JP2021065804A - Method for removing titanium nitride-containing lump - Google Patents

Abstract

To provide a method for removing a high-hardness titanium nitride-containing lump including metal oxides adhering and accumulating onto a cleaning object without damaging the cleaning object.SOLUTION: A removal method for titanium nitride-containing lumps includes a process of immersing a cleaning object in a mixture liquid of nitric acid and acidic ammonium fluoride, and a process of physically treating the cleaning object after the immersing process. In this case, (1) the immersion process is preferably carried out by dividing plural cleaning objects into plural groups comprising one or more and by charging one group at a time in an immersion tank additionally spacing in terms of time, and (2) the physically treating process includes preferably one or more operations among air injection, water injection, buffing, brushing and flushing.SELECTED DRAWING: None

Description

The present invention relates to a method for removing titanium nitride-containing lumps adhering to and deposited on a cleaning object, in particular, removing a high-hardness lump containing a metal oxide together with titanium nitride without damaging the cleaning object. Again, the above-mentioned removal method that can be effectively used.

Titanium nitride is not only extremely hard, but also non-toxic and has excellent properties such as exhibiting a golden color. Therefore, it protects the surface of ceramics such as semiconductors, metal members such as dentistry, and other materials. It is used in a wide range of fields such as decoration and decoration.

The surface protective layer of titanium nitride is generally formed by a CVD method or the like, and at this time, an object to be protected (that is, various objects as described above forming the titanium nitride layer) is subjected to an apparatus such as a CVD method. A jig to hold is used.
Various materials such as metal and ceramic are used as the material of this jig, but carbon-based materials are heavily used from the viewpoints of easy processing, non-toxicity, and ease of handling.

By the way, in recent years, it has become difficult to obtain carbon-based materials in the market, and it is becoming increasingly necessary to repeatedly use the above jigs a plurality of times.
In repeated use, the titanium nitride lumps adhering to and accumulating on the jig must be removed.

Various techniques for removing titanium nitride have been conventionally proposed. For example
(I) A titanium stripping solution (Japanese Patent Laid-Open No. 2005-232559) comprising an aqueous solution having a pH of 5 or less containing a fluorine compound and a metal ion (trivalent titanium, divalent iron) having a reducing power.
(Ii) Titanium nitride stripping solution containing hydrofluoric acid, hydrogen peroxide, water, and inorganic acids (sulfuric acid, nitric acid, hydrochloric acid) other than hydrofluoric acid (Japanese Patent Laid-Open No. 2009-19255),
(Iii) Titanium nitride stripping solution containing hydrofluoric acid, hydrogen peroxide, a water-soluble organic solvent (imidazole, pyrazole), and an anticorrosive agent (ether) (Japanese Patent Laid-Open No. 2009-21516).
(Iv) Titanium nitride stripping solution containing hydrofluoric acid, hydrogen peroxide, and a water-soluble organic solvent (polyhydric alcohol, alkyl ether thereof) (Japanese Patent Laid-Open No. 2009-44129).
And so on.

Japanese Unexamined Patent Publication No. 2005-232559 Japanese Unexamined Patent Publication No. 2009-19255 Japanese Unexamined Patent Publication No. 2009-21516 Japanese Unexamined Patent Publication No. 2009-44129

However, it is impossible to cleanly remove the titanium nitride-containing mass from the jig by using any of the above-mentioned stripping solutions (i) to (iv) and by changing the method of using the stripping solution. Of course, the jig has not been reused.
For jig materials, especially jigs manufactured from carbon-based materials, there is a serious problem in obtaining jig materials, so it is urgent to develop a beautiful removal technology for titanium nitride-containing lumps. ing.

In the present invention, under the above circumstances, the object to be formed of the titanium nitride protective layer (sometimes referred to as “object to be formed of the titanium nitride layer” in the present specification) is the protective layer of a CVD device or the like. The titanium nitride-containing lumps adhering to and accumulating on the jig used for holding in the forming apparatus (sometimes referred to as “object to be cleaned” in the present specification) are neatly removed, and the jig is repeated. The subject is to propose a method of cleaning to a usable state.

As a result of repeated studies to solve the above problems, the present inventor has obtained the following findings.
(1) When an attempt was made to remove the titanium nitride-containing mass using the stripping solutions (i) to (iv) above, a mass (layer) of an oxide of a metal other than Ti was found in the lower layer of the titanium nitride mass (layer). It is present and this metal oxide cannot be removed by the stripping solution described above.
(2) The above metal oxide is formed as a base layer when forming a titanium nitride protective layer, and if this base layer is not formed, titanium nitride protection may be provided depending on the object to which the titanium nitride protective layer is formed. Not only is the layer not formed well, but there is also the problem that the protective layer that has been formed is easily peeled off.
(3) Naturally, this metal oxide also adheres and deposits on the jig, and titanium nitride adheres and deposits on the metal oxide. Therefore, when the above jig is used repeatedly, it is necessary to cleanly remove not only the titanium nitride lump (layer) but also the metal oxide lump (layer).
(4) Therefore, first, while studying a drug for removing the titanium nitride mass (layer), when a mixed solution of a specific fluorine compound and nitric acid was used, only the titanium nitride mass (layer) was beautifully removed. Instead, the metal oxide mass (layer) existing under the layer is in a roughened state, and it is confirmed that this roughened surface is hangnail-like by the touch of fingers. It was.
(5) Further, it is preferable to perform the operation of washing the object to be cleaned with the above-mentioned mixed solution by immersing it in the mixed solution from the viewpoint of convenience. Sufficient removal may be difficult even if the operation is used in combination. In such a case, it was found that the removal proceeds unexpectedly when the untreated cleaning object is additionally immersed.
(6) Next, as a result of pursuing the method for removing the metal oxide mass (layer) roughened in the shape of a hangnail, air or water injection, buffing, brushing, etc. It was confirmed that the removal by physical treatment can be performed while smoothing the surface of the object to be cleaned, and it was found that the object to be cleaned that has been physically treated can be reused as it is.

The present invention has been proposed based on the above findings.
(1) A method for removing a titanium nitride-containing mass, which comprises a step of immersing a cleaning object in a mixed solution of nitric acid and acidic ammonium fluoride and a step of physically treating the cleaning object.
At this time, (2) in the above dipping step, a plurality of objects to be cleaned are divided into a plurality of groups consisting of one or more, and one set is additionally charged into the dipping tank at intervals of time (that is, first). The first set of the above is immersed, and after an appropriate time elapses, the second set is added to the first set), and the dipping step is at room temperature to 90 ° C. for 0.5 hours to 30. It may be carried out on a daily basis, or a stirring operation may be added. Further, (3) the physical treatment step may be performed by any one or more of air injection, water injection, sand injection, buffing, brushing, and washing with water.
In the case of the split additional charging method of (2) above, the number of the first set to be charged is more than half of the total number of objects to be cleaned, and the number of the final set to be charged is about 20% or less of the total number of objects to be cleaned. It is preferable to do so.

According to the method of the present invention, a titanium nitride ingot (layer) containing a metal oxide adhered and deposited during a titanium nitride layer forming operation on a cleaning object such as a tool for holding a titanium nitride layer forming object in a CVD device or the like. Can be cleaned and removed neatly with a simple operation, and the tool or the like can be used repeatedly.
In particular, in a carbon-based tool in which the raw material is depleted, the metal oxide-containing titanium nitride lump (layer) adhering to and deposited on the tool is beautiful without damaging the tool by the method of the present invention. Since the tool can be removed by exhibiting a surface state, the tool processed by the method of the present invention can be used repeatedly as it is.

The mixed solution of nitric acid and acidic ammonium fluoride in the method of the present invention, that is, the mixed solution used in the dipping step of the object to be cleaned is a solution prepared by dissolving acidic ammonium fluoride (powder) in nitric acid (liquid), and is generally a solution. , Commercially available powdered acidic ammonium fluoride is added to a commercially available concentrated nitric acid (98% concentration) solution, or conversely, a commercially available concentrated nitric acid solution is injected into powdered acidic ammonium fluoride, stirred, and powdered acidic foot. Prepared by dissolving ammonium carbonate in a concentrated nitric acid solution. At this time, the mixing ratio of concentrated nitric acid and acidic ammonium fluoride is not particularly limited, but in consideration of work efficiency, 0.5 to 10 liters of concentrated nitric acid per 1 kg of acidic ammonium fluoride (hereinafter, liter is “L”. ", Milliliter is written as" mL ").

The dipping step of the method of the present invention is carried out by immersing the object to be cleaned in the mixed solution prepared as described above. The temperature of the mixed solution at the time of immersing is preferably about room temperature to 90 ° C., and the dipping time is long. It cannot be unconditionally determined depending on the size and number of objects to be cleaned, as well as the adhesion state of the titanium nitride lumps to be removed, but 1 to 1 to small ones of 10 mm × 10 mm × 10 mm or less to large ones of about 1000 mm × 1000 mm × 1000 mm. When washing about 100 pieces, it takes about 0.5 hours to 30 days.
During this dipping step, a stirring operation may be added, and the stirring operation may be performed continuously during the dipping step, at regular intervals, or randomly and intermittently. As for the degree of stirring, about 0.1 to 10 rpm is generally sufficient because it is sufficient that the above-mentioned mixed solution can come into contact with the entire surface of the object to be cleaned.

Further, in the present invention, the plurality of objects to be cleaned are divided into a plurality of groups including one or more, the first group is immersed, and after an appropriate time elapses, the second group is used as the first group. It may be thrown in in an additional manner and immersed. The time interval at this time varies depending on the state of adhesion of the titanium nitride mass (layer) adhering to and accumulating on the object to be cleaned. Generally, the state of the immersion tank is visually observed and the dissolution reaction is becoming stationary. When it is in a judged state (for example, when the dissolution / exfoliation << elution >> from the object to be cleaned decreases or disappears), the second set is put in and the immersion treatment is continued. Again, when it is determined that the elution in the immersion tank is becoming stationary, a third set of objects to be cleaned is additionally immersed. The immersion step is completed by repeating such an additional immersion operation.
In this split additional charging method, the cleaning efficiency is such that the number of the first set to be charged is at least half of the total number of objects to be cleaned, and the number of the final set to be charged is about 20% or less of the total number of objects to be cleaned. It is preferable from the point of view, and the number of pairs between the first pair and the final pair may be gradually reduced, conversely, gradually increased, or randomly many → few → many, Alternatively, the same number → the same number → the same number may be used.
Needless to say, even in the dipping step by the divided additional charging, the immersion step may be performed at the above temperature and time, and a stirring operation may be further added.

In the above dipping step, the titanium nitride mass (layer) adhering to and accumulating on the object to be cleaned dissolves in the above mixed solution, in other words, the immersion liquid and is separated from the object to be cleaned. At this time, the metal oxide mass (layer) that is mainly adhered and deposited on the lower side of the titanium nitride mass (layer) is partially peeled off, but most of the surface is hangnailed by the touch of a finger or visually. Remain.
This hangnail metal oxide mass (layer) is removed by the physical treatment in the next step.

The physical treatment in the present invention is any one or more of air injection, water injection, buffing, brushing, and washing with water, and a metal oxide mass (when a small amount of titanium nitride is contained) remaining after the above dipping step is performed. An appropriate method is selected depending on the amount and condition of (there is also), the structure and size of the object to be cleaned to which the metal oxide mass adheres and remains, or the type of the constituent material. For example, when the structure is simple and the constituent material has high strength, it can be beautifully removed by injecting air or water at a certain injection pressure from a large size to a small size.
Further, in such a case, a method of injecting water or air in water can be adopted, and the speed of physical processing can be improved.

The injection nozzle used when injecting the above-mentioned air or water is preferably a convertent type, and its size or injection pressure is determined by the amount and state of the above-mentioned residual metal oxide mass, the structure and size of the object to be cleaned, and the like. It is appropriately selected according to the type of constituent material.
For example, a carbon graphite outer diameter of 100 to 700 mm, an inner diameter of 70 to 650 mm, and a thickness of 10 to 50 mm. A holding portion having a structure having a plurality of openings (approximately a cylindrical shape having an opening diameter of 5 to 25 mm and a depth of about 3 to 15 mm), or a carbon graphite outer diameter of 100 to 700 mm, an inner diameter of 8 to 50 mm, and a thickness. It has a structure in which a plurality of concave holding portions (similar to the above, an opening diameter of 5 to 25 mm and a depth of about 3 to 15 mm are roughly cylindrical) are provided on a thin-walled donut-shaped disc-shaped disc surface having a diameter of 10 to 50 mm. When a cylinder is used as an object to be cleaned, the nozzle size is 0.1 to 0.7 mm at the tip and 0.5 to 1.5 mm at the rear, and the injection pressure is about 1 to 50 L / sec. In the case of a jet bath type that injects water or air in water, use a water tank that is large enough to allow multiple objects to be cleaned to be immersed.

Further, in the case of only washing with water without injecting air or water, a stirring means having at least one blade such as a flat plate or a spiral is used. The ingredients and dimensions of the stirring means are appropriately selected from synthetic resin, metal, wood, etc., depending on the amount and condition of the remaining metal oxide mass, the structure and size of the object to be cleaned, and the type of constituent material. The dimensions are also appropriately selected.

Further, in the method of the present invention, the above-mentioned metal oxide mass can be removed by buffing or brushing. The ingredients and dimensions of buffing materials and brushing materials also depend on the amount and condition of the above-mentioned residual metal oxide mass, or the structure and size of the object to be cleaned, and the type of constituent material. It is appropriately selected from animals. In addition, a mixture of metal and ceramic (for example, a brush in which diamond particles are mixed in a metal base) or a mixture of synthetic resin and plant (for example, a short branch of bamboo or palm is mixed in a synthetic resin base). You can also use a brush, etc.).
When buffing or brushing is adopted as the physical treatment in the method of the present invention, the object to be washed is washed with water prior to these treatments to remove the immersion treated water remaining on the surface of the object. However, in the case of physical treatment by jetting air or water as described above or washing with water, it is possible to eliminate the need for washing with water prior to these treatments.

In the embodiment of the present invention, it is a figure for demonstrating the configuration example of the apparatus used at the time of performing the physical processing, (A) is the explanatory view of the apparatus main body of one example, (B) is the apparatus main body of another example. (C) is a conceptual diagram showing a control unit.

[Example 1]
Concave holding part (holding part for titanium nitride layer forming object, opening diameter 20 mm) along the outer circumference of a thin donut-shaped disk (stag beetle) made of carbon graphite with an outer diameter of 300 mm, an inner diameter of 250 mm, and a thickness of 25 mm. , Jig used when forming the layer by the CVD method while holding the object to be cleaned (titanium nitride layer forming object) having a structure having a plurality of objects (cylindrical shape having a depth of 10 mm) << Hereinafter, "used jig" In addition, 12 pieces of alumina formed as a base layer of the titanium nitride layer << hereinafter may be described as "with a base layer">>) were treated by the following steps.

<Immersion process>:
A two-tank type immersion tank was used in which a liquid for immersion was injected into an inner tank (content capacity 200 L) and hot water was circulated through the outer tank to keep the temperature of the immersion liquid in the inner tank constant.
The immersion liquid was 20 kg of acidic ammonium fluoride (trade name "Acid Ammonium Fluoride (D)" manufactured by Stella Chemifa Co., Ltd.) and nitric acid (trade name "CAS 7697-37-2" manufactured by Takeda Shoji Co., Ltd. with a concentration of 98%) 14 Prepared by mixing at a ratio of .2 L.
150 L of this immersion liquid was injected into the inner tank of the above-mentioned immersion tank, and hot water at 80 ° C. was circulated through the outer tank to maintain the immersion liquid at 65 ° C.

In this immersion liquid, the entire amount of the above 12 objects to be cleaned is buried at intervals of 20 mm, 15 L of the immersion liquid is discharged every 8 hours, and 13.5 L of a new immersion liquid for make-up is discharged. The soaking solution was solid-liquid separated, mixed with 1.5 L separated from the liquid, and the operation of returning the mixed soaking solution for make-up to the inner tank was repeated. During this operation, the inner tank was manually stirred at about 3 rpm using a stirring rod, and the object to be cleaned was manually rotated by 180 ° along its circumference.

After performing the above operation for 48 hours, 12 objects to be cleaned were taken out and the surface condition was visually observed. As a result, although there are some differences, the surface of all 12 pieces is raised even to the inner surface of the holding part of the titanium layer forming object, and most of the titanium nitride lumps (layers) can be removed. It was confirmed that there was.

<Physical processing process>:
The object to be washed after the immersion treatment taken out from the immersion tank was washed with tap water and dried.
A metal brush for large to small areas (trade name "Scotch-Brite Industrial Pad 7448" manufactured by 3M) and diamond electrodeposition for extremely small areas are applied to the entire surface including the inner surface of the holding part of the object to be cleaned after drying. Using a brush (diamond shaving) (brand name "DCW5" sold by VIP Shoko Co., Ltd.), brushing is done manually, and by visual inspection and touch of the finger, the hangnail state of almost the entire surface of the object to be cleaned is eliminated and smooth. Brushing was performed until it became full.
The object to be cleaned after the physical treatment could be satisfactorily used as it is as a holder for the object to form a titanium nitride film in the CVD apparatus.

[Example 2]
The physical treatment step was carried out in the same manner as in Example 1 except that an iron buff material (trade name “Iron Buff TE100 × 12.7” manufactured by Ariake Abrasive Abrasives Co., Ltd.) was used and buffing was performed manually.
As a result, as in the case of Example 1, the surface including the inner surface of the holding portion is not hangnailed and the surface is smooth, and the surface is satisfactorily used as it is as a holder for the titanium nitride film-forming object of the CVD apparatus. Was done.

[Example 3]
The physical treatment process is performed in a water tank with a jet injector (content capacity 200L) (a water tank with the same specifications as the inner tank of the dipping tank used in the dipping process, and a jet bath for general household use. Inject 150 L of tap water into the bubble generator BU-BU main body set ""), bury 12 objects to be cleaned after immersion treatment at intervals of 200 mm, and inject water into the water. The treatment was carried out in the same manner as in Example 1 except for washing with water. The water injection pressure was adjusted while visually observing the state of the object to be cleaned. As a result of washing for 24 hours with the injection pressure at full power, almost all the objects to be washed could be washed well. A part of the remaining material was treated with the same brush or buff as in Example 1 or 2 as if it were a finishing treatment.
The cleaning object after the treatment could be satisfactorily used as it is as a holder for the titanium nitride film forming object of the CVD apparatus, as in Examples 1 and 2.

[Example 4]
In this example, the physical treatment steps are performed at four locations at equal intervals in the length direction of the transparent synthetic resin cylindrical container (diameter 900 mm × length 1200 mm, opening and closing in the length direction) shown in FIG. 1 (A). It has four air or water injection nozzle installation parts 2, 2 ... In the circumferential direction, and each installation part has four injection nozzles 3, 3 ... at equal intervals (that is, every 45 °). installed. The direction of the nozzle was inclined by 15 ° from the inner surface of the cylindrical container.
For the nozzles 3, 3, ..., A convertent type having a tip portion of 0.5 mm and a rear end portion of 0.8 mm was used. As shown in FIG. 1C, the nozzles 3, 3 ... Are connected to the control unit 5 via the conduits 4, 4 ..., And the injection pressure is controlled to supply air and water. ..
Positioned below the injection nozzle installation portions 2, 2, ... In the transparent synthetic resin cylindrical container 1 having such a configuration (that is, the holding portion of the cleaning object whose air, water, or sand from the nozzle is not shown). After setting four immersion-treated cleaning objects (not shown) so that they are impacted on the installation surface at an angle of 15 °), air is injected at 30 L / sec from each of the four nozzles. Was processed in the same manner as in Example 1.

As a result, I tried to adjust the injection pressure while visually observing the inside from the outside of the transparent container, but the fine powder (fine metal oxide fine particles) peeling off from the object to be cleaned was scattered throughout the container. In order to block the view, the air injection was stopped every 30 minutes for 5 minutes, and the operation of submerging the scattering in the container and visually observing was continued for 5 hours. , Almost everything was removed. The small amount of residual mass was removed by buffing.
The cleaning object after the treatment could be satisfactorily used as it is as a holder for the titanium nitride film forming object of the CVD apparatus, as in Examples 1 to 3.
The same physical processing as described above was repeated for the remaining 8 pieces by 4 pieces each. The result was similar to the above.

[Example 5]
The treatment was carried out in the same manner as in Example 4 except that the air injection was replaced with water injection and the injection pressure was 20 L / sec.
The cleaning object after the treatment could be satisfactorily used as it is as a holder for the titanium nitride film forming object of the CVD apparatus, as in Examples 1 to 4.

[Examples 6 to 9]
Concave holding part (holding part of titanium nitride layer forming object) along the side side of a thin rectangular disc (rectangular frame shape) with an outer side of 700 mm, an inner side of 450 mm, and a thickness of 40 mm made of carbon graphite. A cleaning object having a structure having a plurality of openings (a cylindrical shape having an opening diameter of 25 mm and a depth of 15 mm) (a jig used when holding the titanium nitride layer forming object and forming the layer by the CVD method). 3 pieces, 5 objects to be cleaned with the same shape and dimensions as Examples 1 to 5, and the same thin-walled donut-shaped disk shape as Examples 1 to 5 except that the dimensions are outer diameter 200 mm, inner diameter 150 mm, and thickness 25 mm. Five (rectangular) objects to be cleaned were prepared and processed by the following steps.

The treatment was carried out in the same manner as in Example 1 except that the mixing ratio of the dipping liquid in the dipping treatment step was as shown in Table 1 and the dipping conditions were as shown in Table 1. Of course, the replacement / stirring of the immersion liquid and the rotation of the object to be cleaned were also carried out in substantially the same manner as in Example 1.
As a result, in each of the examples, although there are some differences as in the case of the first embodiment, the surface of all 12 objects to be cleaned including the inner surface of the holding portion of the formed object is raised. It was confirmed that most of the titanium nitride lumps (layers) could be removed.

The objects to be washed after the immersion treatment in Examples 6 to 9 were subjected to the physical treatment steps shown in Table 2.
The results are as shown in Table 2.

[Example 10]
<Immersion process>:
Twelve cleaning objects having the same shape as in the first embodiment are divided into two sets of 11 sets (first set) and one set (second set), and 11 of the first set. The pieces were dipped under the same conditions as the dipping process of Example 1, and when about 24 hours had passed, one of the second set was additionally dipped in this dipping tank while continuing the dipping process, and about 24 hours had passed. The immersion treatment was carried out for 22 hours.

(2) Twelve objects to be cleaned having the same shape as in Example 1 are arranged in nine sets (first set), two sets (second set), and one set (third set). The nine pieces of the first group were subjected to the dipping treatment under the same conditions as the dipping treatment step of Example 1, and when about 22 hours had passed, the dipping treatment was continued while the dipping treatment was continued in the dipping tank. Two of the second set were additionally immersed, and when about 17 hours had passed, one of the third set was additionally immersed in this immersion tank while continuing the immersion treatment, and the immersion treatment was performed for about 6 hours. It was.

(3) Twelve cleaning objects having the same shape as in Example 1 are arranged in eight sets (first set), two sets (second set), and two sets (third set). The eight pieces of the first group were subjected to the dipping treatment under the same conditions as the dipping treatment step of Example 1, and when about 21 hours had passed, the dipping treatment was continued while the dipping treatment was continued in the dipping tank. The 2 pieces of the 2nd group are additionally immersed, and when about 15 hours have passed, the 2 pieces of the 3rd group are additionally immersed in this immersion tank while continuing the immersion treatment, and the immersion treatment is performed for about 5 hours. It was.

(4) Twelve cleaning objects having the same shape as in Example 1 are arranged in nine sets (first set), one set (second set), and two sets (third set). The nine pieces of the first group were subjected to the dipping treatment under the same conditions as the dipping treatment step of Example 1, and when about 22 hours had passed, the dipping treatment was continued while the dipping treatment was continued in the dipping tank. One of the second set was additionally immersed, and when about 17.5 hours had passed, while continuing the immersion treatment, the two of the third set were additionally immersed in this immersion tank, and the immersion treatment was performed for about 5 hours. Was done.

(5) Twelve cleaning objects having the same shape as in Example 1 are divided into 6 sets (1st set), 4 sets (2nd set), and 2 sets (3rd set). The 6 pieces of the 1st group were subjected to the dipping treatment under the same conditions as the dipping treatment step of Example 1, and when about 20 hours had passed, the dipping treatment was continued while being placed in this dipping tank. The 4 pieces of the 2nd group were additionally immersed, and when about 18 hours had passed, the 2 pieces of the 2nd group were additionally immersed in this immersion tank while continuing the immersion treatment, and the immersion treatment was performed for about 5 hours. It was.

(6) Twelve objects to be cleaned having the same shape as in Example 1 are divided into 6 sets (1st set), 3 sets (2nd set), and 2 sets (3rd set). And one set (fourth set), and six sets of the first set were dipped under the same conditions as the dipping process of Example 1, and when about 20 hours had passed, While continuing the dipping process, the 3 pieces of the second set were additionally immersed in the dipping tank, and when about 17 hours had passed, the dipping process was continued and the 2 pieces of the 3rd set were placed in the dipping tank. After about 3 hours of additional immersion, one of the fourth set was additionally immersed in this immersion tank while continuing the immersion treatment, and the immersion treatment was performed for about 3 hours.

<Results of the above dipping treatment steps (1) to (6)>:
When each of the 12 objects to be cleaned after being treated in the dipping treatment steps (1) to (6) was taken out and the surface condition was visually observed, all of the dipping treatment steps (1) to (6) were performed. It was confirmed that the hangnail was larger than that of Example 1, and that when the worker picked one of the hangnail with his fingers and pulled it upward, the hangnail was easily peeled off. By visual observation after peeling, it was confirmed that the surface of the material itself of the titanium layer forming object was exposed.

<Physical processing process>:
Each of the 12 objects to be cleaned after the treatments in the dipping treatment steps (1) to (6) were treated in the same manner as in the physical treatment steps of Examples 1 to 5.
As a result, both the same brushing treatment as in Example 1 and the same buffing treatment as in Example 2 were performed with a total time of 12 pieces, and the processing time of Examples 1 and 2 (about 5 hours each) was about 60%. It was able to be reused well in time (about 3 hours each). Further, the water injection treatment in water as in Example 3 takes about 15 hours, and the air injection treatment as in Example 4 and the water injection treatment as in Example 5 both take about 3 hours and are reused satisfactorily. We were able to.

[Example 11]
<Immersion process>:
The same dipping treatment as in the dipping treatment steps (1) and (5) of Example 10 was carried out with the dipping liquid having the blending ratio shown in Table 3 under the temperature conditions shown in Table 3.
The results for the immersion time are as shown in Table 3.

<Physical processing process>:
Each of the 12 objects to be cleaned after being treated in the dipping treatment steps (1) and (5) was treated in the same manner as in the physical treatment steps of Examples 1 to 5.
As a result, both the same brushing treatment as in Example 1 and the same buffing treatment as in Example 2 were performed with a total time of 12 pieces, and the processing time of Examples 1 and 2 (about 5 hours each) was about 60%. It was able to be reused well in time (about 3 hours each). Further, the water injection treatment in water as in Example 3 takes about 15 hours, and the air injection treatment as in Example 4 and the water injection treatment as in Example 5 both take about 3 hours and are reused satisfactorily. We were able to.

[Example 12]
A thin donut-shaped disc made of carbon graphite with an outer diameter of 300 mm, an inner diameter of 55 mm, and a thickness of 25 mm. Twenty-four objects (used jigs with an alumina base layer) were processed by the following steps.

<Immersion process>:
The cleaning object was divided into two sets of 12 pieces each, and each set was carried out in the same manner as in Example 1. The results were substantially similar to Example 1 in all of the two sets.

<Physical processing process>:
(1) The same diamond electrodeposition brush treatment as in Example 1 was performed on the two objects to be cleaned after the dipping treatment step. The results were substantially the same as in Example 1 except that the treatment time was about 30 minutes in total for the two objects to be washed.
(2) The same iron buffing treatment as that used in Example 2 was performed on the other two objects to be cleaned after the dipping treatment step. The results were substantially the same as in Example 2 except that the treatment time was about 30 minutes in total for the two objects to be washed.
(3) The same jet bath treatment as in Example 3 was performed on the other 6 objects to be cleaned after the dipping treatment step. The results were substantially the same as in Example 3 except that the treatment time was about 15 hours.
(4) With respect to the other four objects to be cleaned after the dipping treatment step, in this example, as shown in a partially explanatory view of FIG. 1 (B), a transparent synthetic resin cylindrical shape similar to that of FIG. 1 (A). Vessel (diameter 900 mm x length 1200 mm, open / close in the length direction) 4 places at equal intervals in the length direction of 1 (omitted in FIG. 1 (B)), 1 place on the apex of the upper curved surface of the cylindrical container 1. And, there are three pipes 6, 6 and 6 for installing nozzles for air or water injection in the vertical direction from a total of three places, one at equal intervals in the left-right direction from the apex, and the figure (B). As shown in, the installation pipe 6 at the apex has four nozzles 3, 3, 3, 3 in the length direction, and the installation pipes 6 and 6 in the left-right direction have two nozzles 3 in the length direction, respectively. For the nozzles 3, 3 ... To which the, 3, 3, 3 are attached, the same convertent type as that shown in FIG. 1 (A) was used. As in the case of FIG. 1 (A), the nozzles 3, 3 ... Are connected to the control unit 5 by the conduits 4, 4 ... shown in FIG. 1 (C), the injection pressure is controlled, and air or air or Water is supplied.
Facing the nozzles 3, 3 ... In the transparent synthetic resin cylindrical container 1 having such a configuration (that is, the air, water, or sand from the nozzles hits the holding portion installation surface of the object to be cleaned (not shown). After setting four immersion-treated cleaning objects (not shown), the treatment is the same as in Example 4 except that air is injected at 30 L / sec from each of the four nozzles. did.
As a result, as in Example 4, it is extremely difficult to visually observe the inside. Therefore, as in Example 4, the air injection is stopped every 30 minutes for 5 minutes, and the scattering in the container is submerged for visual observation. When it was continued for 5 hours, almost all of the metal oxide lumps were removed as in the case of Example 4. Subsequently, in order to perform the same air injection treatment on the opposite side surfaces of the nozzles 3, 3, 3 ..., The object to be cleaned was inverted and air injection was performed for 1 hour. As a result, this surface was used. Almost all of the lumps that remained in the air were removed. After that, the slightly remaining lumps were removed by buffing on both sides.
(5) Four other objects to be cleaned after the immersion treatment step were treated in the same manner as in (4) above except that the air injection was changed to water injection and the injection pressure was 20 L / sec.
The object to be cleaned after the treatment could be satisfactorily used as it is as a holder for the object to form a titanium nitride film in the CVD apparatus.

[Example 13]
<Immersion process>:
The object to be cleaned having the same shape as in Example 12 was divided into the same groups as in Examples 10 (1) to (6), and the same dipping treatment as in Examples 10 (1) to (6) was performed. ..

<Results of the above dipping treatment steps (1) to (6)>:
When each of the 12 objects to be cleaned after being treated in the dipping treatment steps (1) to (6) was taken out and the surface condition was visually observed, all of the dipping treatment steps (1) to (6) were performed. It was confirmed that the hangnail was larger than that of Example 12, and when the worker picked one of the hangnail with his fingers and pulled it upward, the hangnail was easily peeled off. By visual observation after peeling, it was confirmed that the surface of the material itself of the titanium layer forming object was exposed.

<Physical processing process>:
Each of the 12 objects to be cleaned after the treatments in the dipping treatment steps (1) to (6) were treated in the same manner as in the physical treatment steps of Examples 1 to 5.
As a result, both the same brushing treatment as in Example 1 and the same buffing treatment as in Example 2 were performed with a total time of 12 pieces, and the processing time of Examples 1 and 2 (about 5 hours each) was about 60%. It was able to be reused well in time (about 3 hours each). Further, the water injection treatment in water as in Example 3 takes about 15 hours, and the air injection treatment as in Example 4 and the water injection treatment as in Example 5 both take about 3 hours and are reused satisfactorily. We were able to.

[Example 14]
<Immersion process>:
The same dipping treatment as in the dipping treatment steps (3) and (6) of Example 13 was carried out with the dipping liquid having the blending ratio shown in Table 4 under the temperature conditions shown in Table 4.
The results for the immersion time are as shown in Table 4.

<Physical processing process>:
Each of the 12 objects to be cleaned after the treatments in the dipping treatment steps (3) and (6) were treated in the same manner as in the physical treatment steps of Examples 1 to 5.
As a result, both the same brushing treatment as in Example 1 and the same buffing treatment as in Example 2 were performed with a total time of 12 pieces, and the processing time of Examples 1 and 2 (about 5 hours each) was about 60%. It was able to be reused well in time (about 3 hours each). Further, the water injection treatment in water as in Example 3 takes about 15 hours, and the air injection treatment as in Example 4 and the water injection treatment as in Example 5 both take about 3 hours and are reused satisfactorily. We were able to.

According to the method of the present invention, a nitrogen titanium-containing mass adhering to and accumulating on a jig used when an object forming a titanium nitride protective layer is held in the protective layer forming apparatus such as a CVD apparatus. It can be removed cleanly, and as a result, the jig can be used repeatedly.
Therefore, in the present situation where the material of the jig is depleted, the method of the present invention has extremely useful utility in the industrial field.

1 Container 2 Nozzle installation part 3 Nozzle 4 Pipe 5 Control part 6 Nozzle installation pipe

The present invention relates to a method for removing titanium nitride-containing lumps adhering to and accumulating on a jig made of a carbon-based material , which is a cleaning object, and particularly damages a high-hardness lump containing a metal oxide together with titanium nitride to the cleaning object. The present invention relates to the above-mentioned removing method capable of removing a cleaning object without any trouble and effectively utilizing the cleaning object again.

Titanium nitride is not only extremely hard, but also non-toxic and has excellent properties such as exhibiting a golden color. Therefore, it protects the surface of ceramics such as semiconductors, metal members such as dentistry, and other materials. It is used in a wide range of fields such as decoration and decoration.

The surface protective layer of titanium nitride is generally formed by a CVD method or the like, and at this time, an object to be protected (that is, various objects as described above forming the titanium nitride layer) is subjected to an apparatus such as a CVD method. A jig to hold is used.
Various materials such as metal and ceramic are used as the material of this jig, but carbon-based materials are heavily used from the viewpoints of easy processing, non-toxicity, and ease of handling.

By the way, in recent years, it has become difficult to obtain carbon-based materials in the market, and it is becoming increasingly necessary to repeatedly use the above jigs a plurality of times.
In repeated use, the titanium nitride lumps adhering to and accumulating on the jig must be removed.

Various techniques for removing titanium nitride have been conventionally proposed. For example
(I) A titanium stripping solution (Japanese Patent Laid-Open No. 2005-232559) comprising an aqueous solution having a pH of 5 or less containing a fluorine compound and a metal ion (trivalent titanium, divalent iron) having a reducing power.
(Ii) Titanium nitride stripping solution containing hydrofluoric acid, hydrogen peroxide, water, and inorganic acids (sulfuric acid, nitric acid, hydrochloric acid) other than hydrofluoric acid (Japanese Patent Laid-Open No. 2009-19255),
(Iii) Titanium nitride stripping solution containing hydrofluoric acid, hydrogen peroxide, a water-soluble organic solvent (imidazole, pyrazole), and an anticorrosive agent (ether) (Japanese Patent Laid-Open No. 2009-21516),
(Iv) Titanium nitride stripping solution containing hydrofluoric acid, hydrogen peroxide, and a water-soluble organic solvent (polyhydric alcohol, alkyl ether thereof) (Japanese Patent Laid-Open No. 2009-44129).
And so on.

Japanese Unexamined Patent Publication No. 2005-232559 Japanese Unexamined Patent Publication No. 2009-19255 Japanese Unexamined Patent Publication No. 2009-21516 Japanese Unexamined Patent Publication No. 2009-44129

However, it is impossible to cleanly remove the titanium nitride-containing mass from the jig by using any of the above-mentioned stripping solutions (i) to (iv) and by changing the method of using the stripping solution. Of course, the jig has not been reused.
For jig materials, especially jigs manufactured from carbon-based materials, there is a serious problem in obtaining jig materials, so it is urgent to develop a beautiful removal technology for titanium nitride-containing lumps. ing.

In the present invention, under the above circumstances, the object to be formed of the titanium nitride protective layer (sometimes referred to as “object to be formed of the titanium nitride layer” in the present specification) is the protective layer of a CVD device or the like. The titanium nitride-containing lumps adhering to and accumulating on the jig used for holding in the forming apparatus (sometimes referred to as “object to be cleaned” in the present specification) are neatly removed, and the jig is repeated. The subject is to propose a method of cleaning to a usable state.

As a result of repeated studies to solve the above problems, the present inventor has obtained the following findings.
(1) When an attempt was made to remove the titanium nitride-containing mass using the stripping solutions (i) to (iv) above, a mass (layer) of an oxide of a metal other than Ti was found in the lower layer of the titanium nitride mass (layer). It is present and this metal oxide cannot be removed by the stripping solution described above.
(2) The above metal oxide is formed as a base layer when forming a titanium nitride protective layer, and if this base layer is not formed, titanium nitride protection may be provided depending on the object to which the titanium nitride protective layer is formed. Not only is the layer not formed well, but there is also the problem that the protective layer that has been formed is easily peeled off.
(3) Naturally, this metal oxide also adheres and deposits on the jig, and titanium nitride adheres and deposits on the metal oxide. Therefore, when the above jig is used repeatedly, it is necessary to cleanly remove not only the titanium nitride lump (layer) but also the metal oxide lump (layer).
(4) Therefore, first, in consideration of a medicament for removing titanium nitride mass (layer), when using a mixed solution of a specific fluorine compound and nitric acid, if titanium nitride mass (layer) is beautifully removed met, the metal oxide mass is present on the lower side of the layer (layers) has become a surface roughening condition, the surface roughening condition, in touch finger, confirmed that the shape hangnail Was done.
(5) Further, it is preferable to perform the operation of washing the object to be cleaned with the above-mentioned mixed solution by immersing it in the mixed solution from the viewpoint of convenience. Sufficient removal may be difficult even if the operation is used in combination. In such a case, it was found that the removal proceeds unexpectedly when the untreated cleaning object is additionally immersed.
(6) Next, as a result of pursuing the method for removing the metal oxide mass (layer) roughened in the shape of a hangnail, air or water injection, buffing, brushing, etc. It was confirmed that the removal by physical treatment can be performed while smoothing the surface of the object to be cleaned, and it was found that the object to be cleaned that has been physically treated can be reused as it is.

The present invention has been proposed based on the above findings.
(1) A step of immersing a jig made of a carbon-based material , which is a cleaning target, in a mixed solution of nitric acid and acidic ammonium fluoride, and the cleaning target after the dipping step are air-injected, water-injected, sand-injected, and buffed. pawl in place, a method for removing any one or more physical processing to titanium nitride containing mass adhering deposited carbonaceous material made jig characterized by comprising the step of brushing.
At this time, (2) in the above dipping step, a plurality of objects to be cleaned are divided into a plurality of groups consisting of one or more, and one set is additionally charged into the dipping tank at intervals of time (that is, first). The first set of the above is immersed, and after an appropriate time elapses, the second set is added to the first set), and the dipping step is at room temperature to 90 ° C. for 0.5 hours to 30. It may be carried out on a daily basis, or a stirring operation may be added. Moreover, water injection in (3) the physical processing step may be performed by have use a nozzle or whirlpool.
In the case of the split additional charging method of (2) above, the number of the first set to be charged is more than half of the total number of objects to be cleaned, and the number of the final set to be charged is about 20% or less of the total number of objects to be cleaned. It is preferable to do so.

According to the method of the present invention, a titanium nitride ingot (layer) containing a metal oxide adhered and deposited during a titanium nitride layer forming operation on a cleaning object such as a tool for holding a titanium nitride layer forming object in a CVD device or the like. Can be cleaned and removed neatly with a simple operation, and the tool or the like can be used repeatedly.
In particular, in a carbon-based tool in which the raw material is depleted, the metal oxide-containing titanium nitride lump (layer) adhering to and deposited on the tool is beautiful without damaging the tool by the method of the present invention. Since the tool can be removed by exhibiting a surface state, the tool processed by the method of the present invention can be used repeatedly as it is.

In the embodiment of the present invention, it is a figure for demonstrating the configuration example of the apparatus used when performing the physical processing, (A) is the explanatory view of the apparatus main body of one example, (B) is the apparatus main body of another example. Around the nozzle part in(C) is a conceptual diagram showing a control unit.

The mixed solution of nitric acid and acidic ammonium fluoride in the method of the present invention, that is, the mixed solution used in the dipping step of the object to be cleaned is a solution prepared by dissolving acidic ammonium fluoride (powder) in nitric acid (liquid), and is generally a solution. , Commercially available powdered acidic ammonium fluoride is added to a commercially available concentrated nitric acid (98% concentration) solution, or conversely, a commercially available concentrated nitric acid solution is injected into powdered acidic ammonium fluoride, stirred, and powdered acidic foot. Prepared by dissolving ammonium carbonate in a concentrated nitric acid solution. At this time, the mixing ratio of concentrated nitric acid and acidic ammonium fluoride is not particularly limited, but in consideration of work efficiency, 0.5 to 10 liters of concentrated nitric acid per 1 kg of acidic ammonium fluoride (hereinafter, liter is “L”. ", Milliliter is written as" mL ").

The dipping step of the method of the present invention is carried out by immersing the object to be cleaned in the mixed solution prepared as described above. The temperature of the mixed solution at the time of dipping is preferably about room temperature to 90 ° C., and the dipping time is long. It cannot be unconditionally determined depending on the size and number of objects to be cleaned, as well as the adhesion state of the titanium nitride lumps to be removed, but 1 to 1 to small ones of 10 mm × 10 mm × 10 mm or less to large ones of about 1000 mm × 1000 mm × 1000 mm. When washing about 100 pieces, it takes about 0.5 hours to 30 days.
During this dipping step, a stirring operation may be added, and the stirring operation may be performed continuously during the dipping step, at regular intervals, or randomly and intermittently. As for the degree of stirring, about 0.1 to 10 rpm is generally sufficient because it is sufficient that the above-mentioned mixed solution can come into contact with the entire surface of the object to be cleaned.

Further, in the present invention, the plurality of objects to be cleaned are divided into a plurality of groups including one or more, the first group is immersed, and after an appropriate time elapses, the second group is used as the first group. It may be thrown in in an additional manner and immersed. The time interval at this time varies depending on the state of adhesion of the titanium nitride mass (layer) adhering to and accumulating on the object to be cleaned. Generally, the state of the immersion tank is visually observed and the dissolution reaction is becoming stationary. When it is in a judged state (for example, when the dissolution / exfoliation << elution >> from the object to be cleaned decreases or disappears), the second set is put in and the immersion treatment is continued. Again, when it is determined that the elution in the immersion tank is becoming stationary, a third set of objects to be cleaned is additionally immersed. The immersion step is completed by repeating such an additional immersion operation.
In this split additional charging method, the cleaning efficiency is such that the number of the first set to be charged is at least half of the total number of objects to be cleaned, and the number of the final set to be charged is about 20% or less of the total number of objects to be cleaned. It is preferable from the point of view, and the number of pairs between the first pair and the final pair may be gradually reduced, conversely, gradually increased, or randomly many → few → many, Alternatively, the same number → the same number → the same number may be used.
Needless to say, even in the dipping step by the divided additional charging, the immersion step may be performed at the above temperature and time, and a stirring operation may be further added.

In the above dipping step, the titanium nitride mass (layer) adhering to and accumulating on the object to be cleaned dissolves in the above mixed solution, in other words, the immersion liquid and is separated from the object to be cleaned. At this time, the metal oxide mass (layer) that is mainly adhered and deposited on the lower side of the titanium nitride mass (layer) is partially peeled off, but most of the surface is hangnailed by the touch of a finger or visually. Remain.
This hangnail metal oxide mass (layer) is removed by the physical treatment in the next step.

Physical treatment in the present invention, air injection, water injection, sand injection, and the buffing, brushing only any one or more, including the metal oxide mass (titanium nitride remaining after the immersion step of slightly An appropriate method is selected depending on the amount and condition of the metal oxide mass, the structure and size of the object to be cleaned to which the metal oxide mass adheres and remains, or the type of the constituent material. For example, if the structure is simple and the constituent material is high-strength, it can be removed cleanly by injecting air, water, or sand with a certain injection pressure, from large size to small size. Can be done.
Further, in such a case, a method of injecting water or air in water can be adopted, and the speed of physical processing can be improved.

The injection nozzle used when injecting the above-mentioned air, water , or sand is preferably a convertent type, and its size or injection pressure is determined by the amount and state of the above-mentioned residual metal oxide mass, the structure of the object to be cleaned, and the like. It is appropriately selected according to the size and the type of constituent material.
For example, a carbon graphite outer diameter of 100 to 700 mm, an inner diameter of 70 to 650 mm, and a thickness of 10 to 50 mm. A holding portion having a structure having a plurality of openings (approximately a cylindrical shape having an opening diameter of 5 to 25 mm and a depth of about 3 to 15 mm), or a carbon graphite outer diameter of 100 to 700 mm, an inner diameter of 8 to 50 mm, and a thickness. It has a structure in which a plurality of concave holding portions (similar to the above, an opening diameter of 5 to 25 mm and a depth of about 3 to 15 mm are roughly cylindrical) are provided on a thin-walled donut-shaped disc-shaped disc surface having a diameter of 10 to 50 mm. When a cylinder is used as an object to be cleaned, the nozzle size is 0.1 to 0.7 mm at the tip and 0.5 to 1.5 mm at the rear, and the injection pressure is about 1 to 50 L / sec. In the case of a jet bath type that injects water or air in water, use a water tank that is large enough to allow multiple objects to be cleaned to be immersed.

Further, in the case of only washing with water without injecting air or water, a stirring means having at least one blade such as a flat plate or a spiral is used. The ingredients and dimensions of the stirring means are appropriately selected from synthetic resin, metal, wood, etc., depending on the amount and condition of the remaining metal oxide mass, the structure and size of the object to be cleaned, and the type of constituent material. The dimensions are also appropriately selected.

Further, in the method of the present invention, the above-mentioned metal oxide mass can be removed by buffing or brushing. The ingredients and dimensions of buffing materials and brushing materials also depend on the amount and condition of the above-mentioned residual metal oxide mass, or the structure and size of the object to be cleaned, and the type of constituent material. It is appropriately selected from animals. In addition, a mixture of metal and ceramic (for example, a brush in which diamond particles are mixed in a metal base) or a mixture of synthetic resin and plant (for example, a short branch of bamboo or palm is mixed in a synthetic resin base). You can also use a brush, etc.).
When buffing or brushing is adopted as the physical treatment in the method of the present invention, the object to be washed is washed with water prior to these treatments to remove the immersion treated water remaining on the surface of the object. However, in the case of physical treatment by jetting air or water as described above or washing with water, it is possible to eliminate the need for washing with water prior to these treatments.

[Example 1]
Concave holding part (holding part for titanium nitride layer forming object, opening diameter 20 mm) along the outer circumference of a thin donut-shaped disk (stag beetle) made of carbon graphite with an outer diameter of 300 mm, an inner diameter of 250 mm, and a thickness of 25 mm. , Jig used when forming the layer by the CVD method while holding the object to be cleaned (titanium nitride layer forming object) having a structure having a plurality of objects (cylindrical shape having a depth of 10 mm) << Hereinafter, "used jig" In addition, 12 pieces of alumina formed as a base layer of the titanium nitride layer << hereinafter may be described as "with a base layer">>) were treated by the following steps.

<Immersion process>:
A two-tank type immersion tank was used in which a liquid for immersion was injected into an inner tank (content capacity 200 L) and hot water was circulated through the outer tank to keep the temperature of the immersion liquid in the inner tank constant.
The immersion liquid was 20 kg of acidic ammonium fluoride (trade name "Acid Ammonium Fluoride (D)" manufactured by Stella Chemifa Co., Ltd.) and nitric acid (trade name "CAS 7697-37-2" manufactured by Takeda Shoji Co., Ltd. with a concentration of 98%) 14 Prepared by mixing at a ratio of .2 L.
150 L of this immersion liquid was injected into the inner tank of the above-mentioned immersion tank, and hot water at 80 ° C. was circulated through the outer tank to maintain the immersion liquid at 65 ° C.

In this immersion liquid, the entire amount of the above 12 objects to be cleaned is buried at intervals of 20 mm, 15 L of the immersion liquid is discharged every 8 hours, and 13.5 L of a new immersion liquid for make-up is discharged. The soaking solution was solid-liquid separated, mixed with 1.5 L separated from the liquid, and the operation of returning the mixed soaking solution for make-up to the inner tank was repeated. During this operation, the inner tank was manually stirred at about 3 rpm using a stirring rod, and the object to be cleaned was manually rotated by 180 ° along its circumference.

After performing the above operation for 48 hours, 12 objects to be cleaned were taken out and the surface condition was visually observed. As a result, although there are some differences, the surface of all 12 pieces is raised even to the inner surface of the holding part of the titanium layer forming object, and most of the titanium nitride lumps (layers) can be removed. It was confirmed that there was.

<Physical processing process>:
The object to be washed after the immersion treatment taken out from the immersion tank was washed with tap water and dried.
A metal brush for large to small areas (trade name "Scotch-Brite Industrial Pad 7448" manufactured by 3M) and diamond electrodeposition for extremely small areas are applied to the entire surface including the inner surface of the holding part of the object to be cleaned after drying. Using a brush (diamond shaving) (brand name "DCW5" sold by VIP Shoko Co., Ltd.), brushing is done manually, and by visual inspection and touch of the finger, the hangnail state of almost the entire surface of the object to be cleaned is eliminated and smooth. Brushing was performed until.
The object to be cleaned after the physical treatment could be satisfactorily used as it is as a holder for the object to form a titanium nitride film in the CVD apparatus.

[Example 2]
The physical treatment step was carried out in the same manner as in Example 1 except that an iron buff material (trade name “Iron Buff TE100 × 12.7” manufactured by Ariake Abrasive Abrasives Co., Ltd.) was used and buffing was performed manually.
As a result, as in the case of Example 1, the surface including the inner surface of the holding portion is not hangnailed and the surface is smooth, and the surface is satisfactorily used as it is as a holder for the titanium nitride film-forming object of the CVD apparatus. Was done.

[Example 3]
The physical treatment process is performed in a water tank with a jet injector (content capacity 200L) (a water tank with the same specifications as the inner tank of the dipping tank used in the dipping process, and a jet bath for general household use. Inject 150 L of tap water into the bubble generator BU-BU main body set ""), bury 12 objects to be cleaned after immersion treatment at intervals of 200 mm, and inject water into the water. The treatment was carried out in the same manner as in Example 1 except for washing with water. The water injection pressure was adjusted while visually observing the state of the object to be cleaned. As a result of washing for 24 hours with the injection pressure at full power, almost all the objects to be washed could be washed well. A part of the remaining material was treated with the same brush or buff as in Example 1 or 2 as if it were a finishing treatment.
The cleaning object after the treatment could be satisfactorily used as it is as a holder for the titanium nitride film forming object of the CVD apparatus, as in Examples 1 and 2.

[Example 4]
In this example, the physical treatment steps are performed at four locations at equal intervals in the length direction of the transparent synthetic resin cylindrical container (diameter 900 mm × length 1200 mm, opening and closing in the length direction) shown in FIG. 1 (A). It has four air or water injection nozzle installation parts 2, 2 ... In the circumferential direction, and each installation part has four injection nozzles 3, 3 ... at equal intervals (that is, every 45 °). installed. The direction of the nozzle was inclined by 15 ° from the inner surface of the cylindrical container.
For the nozzles 3, 3, ..., A convertent type having a tip portion of 0.5 mm and a rear end portion of 0.8 mm was used. As shown in FIG. 1C, the nozzles 3, 3 ... Are connected to the control unit 5 via the conduits 4, 4 ..., And the injection pressure is controlled to supply air and water. ..
Positioned below the injection nozzle installation portions 2, 2, ... In the transparent synthetic resin cylindrical container 1 having such a configuration (that is, the holding portion of the cleaning object whose air, water, or sand from the nozzle is not shown). After setting four immersion-treated cleaning objects (not shown) so that they are impacted on the installation surface at an angle of 15 °), air is injected at 30 L / sec from each of the four nozzles. Was processed in the same manner as in Example 1.

As a result, I tried to adjust the injection pressure while visually observing the inside from the outside of the transparent container, but the fine powder (fine metal oxide fine particles) peeling off from the object to be cleaned was scattered throughout the container. In order to block the view, the air injection was stopped every 30 minutes for 5 minutes, and the operation of submerging the scattering in the container and visually observing was continued for 5 hours. , Almost everything was removed. The small amount of residual mass was removed by buffing.
The cleaning object after the treatment could be satisfactorily used as it is as a holder for the titanium nitride film forming object of the CVD apparatus, as in Examples 1 to 3.
The same physical processing as described above was repeated for the remaining 8 pieces by 4 pieces each. The result was similar to the above.

[Example 5]
The treatment was carried out in the same manner as in Example 4 except that the air injection was replaced with water injection and the injection pressure was 20 L / sec.
The cleaning object after the treatment could be satisfactorily used as it is as a holder for the titanium nitride film forming object of the CVD apparatus, as in Examples 1 to 4.

[Examples 6 to 9]
Concave holding part (holding part of titanium nitride layer forming object) along the side side of a thin rectangular disc (rectangular frame shape) with an outer side of 700 mm, an inner side of 450 mm, and a thickness of 40 mm made of carbon graphite. A cleaning object having a structure having a plurality of openings (a cylindrical shape having an opening diameter of 25 mm and a depth of 15 mm) (a jig used when holding the titanium nitride layer forming object and forming the layer by the CVD method). 3 pieces, 5 objects to be cleaned with the same shape and dimensions as Examples 1 to 5, and the same thin-walled donut-shaped disk shape as Examples 1 to 5 except that the dimensions are outer diameter 200 mm, inner diameter 150 mm, and thickness 25 mm. Five (rectangular) objects to be cleaned were prepared and processed by the following steps.

The treatment was carried out in the same manner as in Example 1 except that the mixing ratio of the dipping liquid in the dipping treatment step was as shown in Table 1 and the dipping conditions were as shown in Table 1. Of course, the replacement / stirring of the immersion liquid and the rotation of the object to be cleaned were also carried out in substantially the same manner as in Example 1.
As a result, in each of the examples, although there are some differences as in the case of the first embodiment, the surface of all 12 objects to be cleaned including the inner surface of the holding portion of the formed object is raised. It was confirmed that most of the titanium nitride lumps (layers) could be removed.

The objects to be washed after the immersion treatment in Examples 6 to 9 were subjected to the physical treatment steps shown in Table 2.
The results are as shown in Table 2.

[Example 10]
<Immersion process>:
(1) Twelve cleaning objects having the same shape as in Example 1 are divided into two sets of 11 sets (first set) and one set (second set), and the first set is used. Eleven sets were immersed under the same conditions as the immersion treatment step of Example 1, and when about 24 hours had passed, one of the second set was additionally immersed in this immersion tank while continuing the immersion treatment. Then, the immersion treatment was carried out for about 22 hours.

(2) Twelve objects to be cleaned having the same shape as in Example 1 are arranged in nine sets (first set), two sets (second set), and one set (third set). The nine pieces of the first group were subjected to the dipping treatment under the same conditions as the dipping treatment step of Example 1, and when about 22 hours had passed, the dipping treatment was continued while the dipping treatment was continued in the dipping tank. Two of the second set were additionally immersed, and when about 17 hours had passed, one of the third set was additionally immersed in this immersion tank while continuing the immersion treatment, and the immersion treatment was performed for about 6 hours. It was.

(3) Twelve cleaning objects having the same shape as in Example 1 are arranged in eight sets (first set), two sets (second set), and two sets (third set). The eight pieces of the first group were subjected to the dipping treatment under the same conditions as the dipping treatment step of Example 1, and when about 21 hours had passed, the dipping treatment was continued while the dipping treatment was continued in the dipping tank. The 2 pieces of the 2nd group are additionally immersed, and when about 15 hours have passed, the 2 pieces of the 3rd group are additionally immersed in this immersion tank while continuing the immersion treatment, and the immersion treatment is performed for about 5 hours. It was.

(4) Twelve cleaning objects having the same shape as in Example 1 are arranged in nine sets (first set), one set (second set), and two sets (third set). The nine pieces of the first group were subjected to the dipping treatment under the same conditions as the dipping treatment step of Example 1, and when about 22 hours had passed, the dipping treatment was continued while the dipping treatment was continued in the dipping tank. One of the second set was additionally immersed, and when about 17.5 hours had passed, while continuing the immersion treatment, the two of the third set were additionally immersed in this immersion tank, and the immersion treatment was performed for about 5 hours. Was done.

(5) Twelve cleaning objects having the same shape as in Example 1 are divided into 6 sets (1st set), 4 sets (2nd set), and 2 sets (3rd set). The 6 pieces of the 1st group were subjected to the dipping treatment under the same conditions as the dipping treatment step of Example 1, and when about 20 hours had passed, the dipping treatment was continued while being placed in this dipping tank. The 4 pieces of the 2nd group were additionally immersed, and when about 18 hours had passed, the 2 pieces of the 2nd group were additionally immersed in this immersion tank while continuing the immersion treatment, and the immersion treatment was performed for about 5 hours. It was.

(6) Twelve objects to be cleaned having the same shape as in Example 1 are divided into 6 sets (1st set), 3 sets (2nd set), and 2 sets (3rd set). And one set (fourth set), and six sets of the first set were dipped under the same conditions as the dipping process of Example 1, and when about 20 hours had passed, While continuing the dipping process, the 3 pieces of the second set were additionally immersed in the dipping tank, and when about 17 hours had passed, the dipping process was continued and the 2 pieces of the 3rd set were placed in the dipping tank. After about 3 hours of additional immersion, one of the fourth set was additionally immersed in this immersion tank while continuing the immersion treatment, and the immersion treatment was performed for about 3 hours.

<Results of the above dipping treatment steps (1) to (6)>:
When each of the 12 objects to be cleaned after being treated in the dipping treatment steps (1) to (6) was taken out and the surface condition was visually observed, all of the dipping treatment steps (1) to (6) were performed. It was confirmed that the hangnail was larger than that of Example 1, and that when the worker picked one of the hangnail with his fingers and pulled it upward, the hangnail was easily peeled off. By visual observation after peeling, it was confirmed that the surface of the material itself of the titanium layer forming object was exposed.

<Physical processing process>:
Each of the 12 objects to be cleaned after the treatments in the dipping treatment steps (1) to (6) were treated in the same manner as in the physical treatment steps of Examples 1 to 5.
As a result, both the same brushing treatment as in Example 1 and the same buffing treatment as in Example 2 were performed with a total time of 12 pieces, and the processing time of Examples 1 and 2 (about 5 hours each) was about 60%. It was able to be reused well in time (about 3 hours each). Further, the water injection treatment in water as in Example 3 takes about 15 hours, and the air injection treatment as in Example 4 and the water injection treatment as in Example 5 both take about 3 hours and are reused satisfactorily. We were able to.

[Example 11]
<Immersion process>:
The same dipping treatment as in the dipping treatment steps (1) and (5) of Example 10 was carried out with the dipping liquid having the blending ratio shown in Table 3 under the temperature conditions shown in Table 3.
The results for the immersion time are as shown in Table 3.

<Physical processing process>:
Each of the 12 objects to be cleaned after being treated in the dipping treatment steps (1) and (5) was treated in the same manner as in the physical treatment steps of Examples 1 to 5.
As a result, both the same brushing treatment as in Example 1 and the same buffing treatment as in Example 2 were performed with a total time of 12 pieces, and the processing time of Examples 1 and 2 (about 5 hours each) was about 60%. It was able to be reused well in time (about 3 hours each). Further, the water injection treatment in water as in Example 3 takes about 15 hours, and the air injection treatment as in Example 4 and the water injection treatment as in Example 5 both take about 3 hours and are reused satisfactorily. We were able to.

[Example 12]
A thin donut-shaped disc made of carbon graphite with an outer diameter of 300 mm, an inner diameter of 55 mm, and a thickness of 25 mm. Twenty-four objects (used jigs with an alumina base layer) were processed by the following steps.

<Immersion process>:
The cleaning object was divided into two sets of 12 pieces each, and each set was carried out in the same manner as in Example 1. The results were substantially similar to Example 1 in all of the two sets.

<Physical processing process>:
(1) The same diamond electrodeposition brush treatment as in Example 1 was performed on the two objects to be cleaned after the dipping treatment step. The results were substantially the same as in Example 1 except that the treatment time was about 30 minutes in total for the two objects to be washed.
(2) The same iron buffing treatment as that used in Example 2 was performed on the other two objects to be cleaned after the dipping treatment step. The results were substantially the same as in Example 2 except that the treatment time was about 30 minutes in total for the two objects to be washed.
(3) The same jet bath treatment as in Example 3 was performed on the other 6 objects to be cleaned after the dipping treatment step. The results were substantially the same as in Example 3 except that the treatment time was about 15 hours.
(4) With respect to the other four objects to be cleaned after the dipping treatment step, in this example, as shown in a partially explanatory view of FIG. 1 (B), a transparent synthetic resin cylindrical shape similar to that of FIG. 1 (A). Vessel (diameter 900 mm x length 1200 mm, open / close in the length direction) 4 places at equal intervals in the length direction of 1 (omitted in FIG. 1 (B)), 1 place on the apex of the upper curved surface of the cylindrical container 1. And, there are three air or water injection nozzle installation pipes 6, 6 and 6 in the vertical direction from a total of three places, one at equal intervals in the left-right direction from the apex, and the figure (B). As shown in, the installation pipe 6 at the apex has four nozzles 3, 3, 3, 3 in the length direction, and the installation pipes 6 and 6 in the left-right direction have two nozzles 3 in the length direction, respectively. , 3, 3, 3 were attached.
For the nozzles 3, 3, ..., The same convertent type as that shown in FIG. 1 (A) was used. As in the case of FIG. 1 (A), the nozzles 3, 3 ... Are connected to the control unit 5 by the conduits 4, 4 ... shown in FIG. 1 (C), the injection pressure is controlled, and air or air or Water is supplied.
Facing the nozzles 3, 3 ... In the transparent synthetic resin cylindrical container 1 having such a configuration (that is, the air, water, or sand from the nozzles hits the holding portion installation surface of the object to be cleaned (not shown). After setting four immersion-treated cleaning objects (not shown), the treatment is the same as in Example 4 except that air is injected at 30 L / sec from each of the four nozzles. did.
As a result, as in Example 4, it is extremely difficult to visually observe the inside. Therefore, as in Example 4, the air injection is stopped every 30 minutes for 5 minutes, and the scattering in the container is submerged for visual observation. When it was continued for 5 hours, almost all of the metal oxide lumps were removed as in the case of Example 4. Subsequently, in order to perform the same air injection treatment on the opposite side surfaces of the nozzles 3, 3, 3 ..., The object to be cleaned was inverted and air injection was performed for 1 hour. As a result, this surface was used. Almost all of the lumps that remained in the air were removed. After that, the slightly remaining lumps were removed by buffing on both sides.
(5) Four other objects to be cleaned after the immersion treatment step were treated in the same manner as in (4) above except that the air injection was changed to water injection and the injection pressure was 20 L / sec.
The object to be cleaned after the treatment could be satisfactorily used as it is as a holder for the object to form a titanium nitride film in the CVD apparatus.

[Example 13]
<Immersion process>:
The object to be cleaned having the same shape as in Example 12 was divided into the same groups as in Examples 10 (1) to (6), and the same dipping treatment as in Examples 10 (1) to (6) was performed. ..

<Results of the above dipping treatment steps (1) to (6)>:
When each of the 12 objects to be cleaned after being treated in the dipping treatment steps (1) to (6) was taken out and the surface condition was visually observed, all of the dipping treatment steps (1) to (6) were performed. It was confirmed that the hangnail was larger than that of Example 12, and when the worker picked one of the hangnail with his fingers and pulled it upward, the hangnail was easily peeled off. By visual observation after peeling, it was confirmed that the surface of the material itself of the titanium layer forming object was exposed.

<Physical processing process>:
Each of the 12 objects to be cleaned after the treatments in the dipping treatment steps (1) to (6) were treated in the same manner as in the physical treatment steps of Examples 1 to 5.
As a result, both the same brushing treatment as in Example 1 and the same buffing treatment as in Example 2 were performed with a total time of 12 pieces, and the processing time of Examples 1 and 2 (about 5 hours each) was about 60%. It was able to be reused well in time (about 3 hours each). Further, the water injection treatment in water as in Example 3 takes about 15 hours, and the air injection treatment as in Example 4 and the water injection treatment as in Example 5 both take about 3 hours and are reused satisfactorily. We were able to.

[Example 14]
<Immersion process>:
The same dipping treatment as in the dipping treatment steps (3) and (6) of Example 13 was carried out with the dipping liquid having the blending ratio shown in Table 4 under the temperature conditions shown in Table 4.
The results for the immersion time are as shown in Table 4.

<Physical processing process>:
Each of the 12 objects to be cleaned after the treatments in the dipping treatment steps (3) and (6) were treated in the same manner as in the physical treatment steps of Examples 1 to 5.
As a result, both the same brushing treatment as in Example 1 and the same buffing treatment as in Example 2 were performed with a total time of 12 pieces, and the processing time of Examples 1 and 2 (about 5 hours each) was about 60%. It was able to be reused well in time (about 3 hours each). Further, the water injection treatment in water as in Example 3 takes about 15 hours, and the air injection treatment as in Example 4 and the water injection treatment as in Example 5 both take about 3 hours and are reused satisfactorily. We were able to.

According to the method of the present invention, nitrogen adhering to and accumulating on a jig made of a carbon-based material used when an object forming a titanium nitride protective layer is held in the protective layer forming apparatus such as a CVD apparatus. The titanium-containing lumps can be removed neatly, and as a result, the jig can be used repeatedly.
Therefore, in the present situation where the material of the jig is depleted, the method of the present invention has extremely useful utility in the industrial field.

1 Container 2 Nozzle installation part 3 Nozzle 4 Pipe 5 Control part 6 Nozzle installation pipe

Claims (3)

The process of immersing the object to be cleaned in a mixed solution of nitric acid and acidic ammonium fluoride,
A method for removing a titanium nitride-containing mass, which comprises a step of physically treating an object to be cleaned after a dipping step. The first aspect of the present invention, wherein the plurality of objects to be cleaned are divided into a plurality of groups including one or more, and each group is additionally charged into the immersion tank at intervals of time to perform the immersion step. A method for removing titanium nitride-containing lumps. The method for removing titanium nitride-containing lumps according to claim 1 or 2, wherein the physical treatment step is performed by any one or more of air injection, water injection, sand injection, buffing, brushing, and washing with water.

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