JP2008263027A - Substrate processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To remove an unwanted film containing a silicon oxide based or silicon nitride based highly hardened film, and a rugged face at a high efficiency, and to enhance a polishing face accuracy. <P>SOLUTION: This substrate processing method contains the steps of: bringing a first polishing face which fixes abrasive grains having particles having a chemical effect as a main component with respect to a silicon oxide based or silicon nitride based film 11, 12 into contact with a peripheral part of a semiconductor substrate 10 to polish the substrate 10; and bringing a second polishing face which fixes the abrasive grains having particles having a mechanical effect as a main component into contact with the peripheral part of the substrate 10 to polish the substrate 10. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a substrate processing method for polishing a peripheral portion of a semiconductor substrate, and more particularly to a substrate processing method for removing an unnecessary film or an uneven surface formed on the peripheral portion of a substrate.

With the miniaturization of wiring, the particle and impurity concentration values to be managed are becoming increasingly severe, and the management of the peripheral portion (notch portion and bevel portion) as well as the surface of the semiconductor substrate has become important. . In the manufacturing process of a semiconductor device, fine wiring is formed by repeating film formation / exposure / etching processing of an insulating film such as a SiO ₂ film and a SiN film and a conductive film such as a poly-Si film, a W film, and a Cu film. In this manufacturing process, an insulating film and a conductive film are formed also on the peripheral edge of the substrate, and an unnecessary film and an uneven surface including the insulating film and the conductive film are formed by repeating exposure and etching processes. These unnecessary films and uneven surfaces have become a particle generation source in the manufacturing process, and have become apparent as factors that reduce the yield as the wiring becomes finer.

For example, in the process of forming a trench (Deep Trench) of a trench capacitor, a resist pattern is formed on a laminated insulating film in which a SiN film and a SiO ₂ film are sequentially formed by a CVD method, and this is used as a mask for RIE (Reactive Ion). Etching) sequentially etches the SiO ₂ film, SiN film, and silicon substrate to form a trench. At this time, the generation of plasma and the supply of the etching gas become unstable at the peripheral edge of the substrate, and needle-like protrusions may be formed. These needle-like protrusions are damaged during the transfer of the substrate or during the process and cause particles to be generated. Since such particles lead to a decrease in the yield of the manufactured semiconductor device, it is necessary to remove the needle-like protrusions formed on the peripheral edge of the substrate.

  As a method for treating the peripheral edge of the substrate, there is a polishing technique in which a film to be polished on the substrate is removed by polishing while sliding the substrate having the surface to be polished and the polishing surface while pressing. This polishing technology includes a free abrasive grain method in which a polishing agent containing abrasive particles is supplied to a contact surface between a polishing surface made of nonwoven fabric and a surface to be polished, and a polishing surface and a surface to be polished with the abrasive grains fixed There is a fixed abrasive method that polishes while supplying pure water to the contact surface.

  When removing the needle-like protrusions that occur during trench formation using the fixed abrasive method, conventionally, all of the SiN film and needle-like protrusions on the silicon substrate are polished and removed with diamond abrasive grains # 4000 (grain diameter of about 3 μm) with a high polishing rate. Then, finish polishing was performed with diamond abrasive grains # 10000 (particle diameter of about 0.5 μm). However, according to this method, the polishing time is fast, but the scratches on the silicon substrate due to the diamond abrasive grains # 4000 are large, and the scratches remain after the final polishing with the diamond abrasive grains # 10000 (see, for example, Patent Document 1).

  As a countermeasure in this case, there is a method of using diamond abrasive grains # 10000 for polishing removal of the SiN film, but it takes an enormous time to polish and remove the SiN film of high hardness. As another countermeasure, there is a method of improving the finished surface roughness while gradually reducing the abrasive grain size of diamond abrasive grains # 4000, # 8000, and # 10000. However, since three types of polishing tapes are used, three polishing heads are required, which increases the size of the apparatus. In addition, since the amount of polishing of the silicon substrate becomes large, if the polishing process is performed a plurality of times in the manufacturing process of the semiconductor device, it may deviate from the original shape specification of the substrate and may not flow on the manufacturing line.

Thus, even if it considers from the objective of the grinding | polishing process of a peripheral part of a board | substrate, it is required in order to suppress generation | occurrence | production of a subsequent defect to improve the surface roughness of a to-be-polished surface. However, to improve the surface roughness of the surface to be polished, it is effective to reduce the size of the abrasive grains. However, when removing high hardness films such as SiN films and SiO ₂ films, the polishing rate is significantly reduced and productivity is reduced. There are side effects that get worse.

In order to increase the polishing removal efficiency without deteriorating the surface roughness of the surface to be polished, addition of a chemical solution during polishing has been proposed (see, for example, Patent Document 2). In this proposal, polyethyleneimine or tetramethylammonium hydroxide is added to increase the removal efficiency of the SiN film on the silicon substrate. However, in this method, since the substrate surface is also exposed to the same chemical solution, etching to the silicon substrate becomes a problem as a side effect.
JP 2003-234314 A JP 2007-012943 A

  The present invention has been made in view of the above circumstances, and its object is to provide an unnecessary film or uneven surface including a silicon oxide-based or silicon nitride-based high-hardness film formed on a peripheral portion of a semiconductor substrate. An object of the present invention is to provide a substrate processing method which can be removed with high efficiency and can improve the accuracy of a polished surface.

  A substrate processing method according to an aspect of the present invention includes a first polishing surface in which abrasive grains mainly containing particles having a chemical effect on a silicon oxide or silicon nitride film are fixed to a peripheral portion of a semiconductor substrate. And polishing the substrate, and contacting the peripheral edge of the substrate with a second polishing surface fixed with abrasive grains mainly having a mechanical effect to polish the substrate. It is characterized by that.

  In addition, a substrate processing method according to another embodiment of the present invention uses a polishing liquid containing abrasive grains mainly containing particles having a chemical effect on a silicon oxide-based or silicon nitride-based film, or A process of polishing a peripheral portion of a semiconductor substrate by bringing the abrasive grains into contact with a fixed polishing surface, and using a polishing liquid containing abrasive grains mainly having a mechanical effect, or contacting with a polishing surface having the abrasive grains fixed And polishing the peripheral edge of the substrate.

  According to the present invention, an unnecessary film including a silicon oxide-based or silicon nitride-based high hardness film can be obtained by using both polishing using abrasive grains having a chemical effect and polishing using abrasive grains having a mechanical effect. The uneven surface can be removed with high efficiency, and the polished surface accuracy can be improved.

  The details of the present invention will be described below with reference to the illustrated embodiments.

(First embodiment)
FIG. 1 is a cross-sectional view showing a substrate processing process according to the first embodiment of the present invention, where (a) shows a state before polishing of the substrate to be processed, and (b) shows a state after polishing of the substrate to be processed. Show. In the figure, 10 is a silicon substrate, 11 is a SiO ₂ film, and 12 is a SiN film.

In the present embodiment, abrasive grains mainly composed of ceria (cerium oxide) particles having a chemical effect on SiO ₂ and SiN are fixed to the peripheral portion of the silicon substrate 10 with respect to the structure shown in FIG. The peripheral edge of the substrate is polished by contacting and pressurizing the first polished surface and rotating the substrate 10. Next, the peripheral edge portion of the silicon substrate 10 is polished by contacting and pressurizing the second polishing surface on which diamond abrasive grains mainly having a mechanical effect are fixed and rotating the substrate 10. As a result, as shown in FIG. 1B, the SiO ₂ film 11 and the SiN film 12 are removed at the periphery of the substrate 10 and the surface roughness of the substrate periphery is extremely small.

  Hereinafter, this embodiment will be specifically described.

  FIG. 2 is a schematic configuration diagram showing a fixed abrasive type polishing apparatus used in the present embodiment.

  The stage 21 on which the substrate 20 to be processed is placed is rotatable by a motor 22. The substrate 20 is attracted and fixed to the stage 21 with its center aligned with the center of the stage 21, and a part of the peripheral edge of the substrate 20 contacts the polishing tape 23. The polishing tape 23 is pressed toward the substrate by a polishing head 24 connected to a cylinder (not shown). Then, the peripheral portion of the substrate 20 is polished by rotating the substrate 20 with the motor 22 while the polishing tape 24 is pressed against the peripheral portion of the substrate 20 by the polishing head 24. That is, part or all of the unnecessary film formed on the peripheral edge of the substrate 20 is polished and removed until it reaches the substrate 10. Further, at the time of polishing, pure water is supplied from the nozzle 25 near the center of the substrate to the substrate surface, and this pure water is supplied to the polishing region at the peripheral edge of the substrate.

  As the polishing tape 23, there are two types, a first polishing tape 23a in which abrasive grains mainly composed of particles having a chemical effect are fixed, and a second polishing tape 23b in which abrasive grains mainly having a mechanical effect are fixed. Was used. As shown in FIG. 3A, the first polishing tape 23a is formed by fixing ceria abrasive grains 33 (# 10000: particle diameter of about 0.5 μm) to a PET (polyethylene terephthalate) film 31 with a binder 32. The tape width is 80 mm and the thickness is 50 μm. As shown in FIG. 3B, the second polishing tape 23b is obtained by fixing diamond abrasive grains 34 (# 10000: particle diameter of about 0.5 μm) to a PET film 31 with a binder 32. These two types of polishing tapes 23 can be exchanged as necessary. Furthermore, these polishing tapes 23 can be wound up little by little during polishing, so that a portion deteriorated by polishing can be replaced with a new polishing surface.

As shown in FIG. 1A, a 100 nm thick SiO ₂ film 11 and a 100 nm thick SiN film 12 were sequentially formed on the entire surface of the silicon substrate 10 by a CVD method. The result of applying the polishing method of this embodiment to the removal of the laminated insulating film formed on the peripheral portion of the substrate 10 will be described below.

  Using the polishing apparatus shown in FIG. 2, the first polishing tape 23a to which the ceria abrasive grains shown in FIG. 3 (a) are fixed is set as the polishing tape 23, and the substrate 20 to be processed is adsorbed to the stage 21, While rotating the stage 21 at a predetermined speed and feeding the polishing tape 23 at a predetermined speed, the peripheral edge of the substrate was polished by pressing the polishing tape 23 against the peripheral edge of the substrate.

  The polishing time is twice as long as the conventional combination of diamond abrasive grains # 4000 and diamond abrasive grains # 10000, but the surface roughness after polishing is reduced to 1/5. In addition, the polishing time was shortened to 1/10 and the surface roughness after polishing was reduced to about ½ compared with polishing removal using only diamond abrasive grains # 10000 having the same particle diameter.

On the other hand, when comparing the polishing ability with respect to the silicon substrate 10 from the change in substrate weight before and after polishing, it is 1/150 lower than the diamond abrasive grain # 4000, and further 1/5 compared with the diamond abrasive grain # 10000. And low. These facts indicate that the chemical action of ceria abrasive grains is effective against the SiO ₂ film 11 and the SiN film 12. Further, it shows that no chemical action acts on Si, and it depends on the mechanical strength of the abrasive grains themselves.

When polishing the peripheral edge of the substrate, unlike the substrate surface, since the curvature is in the cross-sectional direction and the circumferential direction of the silicon substrate 10, the polishing head 24 is polished while moving the contact surface along the curvature of the silicon substrate 10. However, excessive polishing is required in order not to generate polishing residue. In this overpolishing, the characteristics of the ceria abrasive grains that have high polishing ability for SiO ₂ and SiN and low polishing ability for Si are advantageous. That is, the ceria abrasive grains are extremely effective for polishing and removing unnecessary films (SiO ₂ film, SiN film) deposited on the peripheral portion of the silicon substrate 10.

  As described above, by using the first polishing tape 23a to which the ceria abrasive grains are fixed, the surface roughness after polishing is sufficiently larger than the combination of the diamond abrasive grains # 4000 and the diamond abrasive grains # 10000 of the prior art. Although reduced, the polishing time becomes longer. Therefore, an embodiment in which the polishing tape 23a to which the ceria abrasive grains (# 10000) are fixed and the polishing tape 23b to which the diamond abrasive grains (# 10000) are fixed is combined for the purpose of shortening the polishing time from the above results will be described.

  First, polishing removal of the laminated insulating film was started with the polishing tape 23a to which the ceria abrasive grains were fixed, and polishing was continued until a part of the underlying Si was exposed. Next, the polishing was changed to polishing with a polishing tape 23b to which diamond abrasive grains having higher polishing ability with respect to the silicon substrate than ceria abrasive grains were fixed. As a result, the total polishing time was improved to about ½ that of the ceria abrasive grains alone. That is, it was the same time as the combination of diamond abrasive grains # 4000 and diamond abrasive grains # 10000 of the prior art. The surface roughness after polishing at this time was reduced to about 1/3 of the conventional combination of diamond abrasive grains # 4000 and diamond abrasive grains # 10000.

  When the polishing step with ceria abrasive polishing tape 23a and the polishing step with diamond abrasive polishing tape 23b are separated, the polishing step is performed using the change in the rotational load of the motor that holds and rotates the substrate to be polished. It is efficient to switch.

  Further, instead of performing the polishing with the polishing tape 23b after the polishing with the polishing tape 23a, the same effect as described above can be obtained by alternately repeating the polishing with the polishing tape 23a and the polishing with the polishing tape 23b. It was.

  Further, as shown in FIG. 4, the polishing tape 23a having ceria abrasive grains fixed at two locations on the peripheral portion of the substrate 20 to be processed and the polishing tape 23b having diamond abrasive grains fixed are simultaneously brought into contact with each other so that the ceria abrasive grains and diamond Polishing with abrasive grains was performed in parallel. In this case, the polishing time was improved to about 1/3 that of the ceria abrasive grains alone. That is, with respect to the combination of diamond abrasive grains # 4000 and diamond abrasive grains # 10000 of the prior art, the polishing time was shortened to 2/3, and the surface roughness after polishing was reduced to about 1/3.

This is due to a synergistic effect of polishing with ceria abrasive grains having high polishing efficiency for the high hardness SiO ₂ film 11 and SiN film 12 and improvement of silicon polishing efficiency with diamond abrasive grains after the underlying silicon substrate is partially exposed. It shows that the removal efficiency of the laminated insulating film has been improved.

As described above, according to the present embodiment, the ceria abrasive grains are fixed to the substrate to be processed on which the unnecessary film including the high hardness film such as the SiO ₂ film 11 and the SiN film 12 is formed on the surface of the silicon substrate 10. By polishing using the polishing tape 23b to which the tape 23a and diamond abrasive grains are fixed, the unnecessary film can be removed with high efficiency, and the polished surface accuracy can be improved. Therefore, it is possible to improve yield by improving productivity and reducing defects.

In place of the laminated film of the SiO ₂ film 11 and the SiN film 12, a 200 nm thick SiO ₂ film is formed on the silicon substrate 10 by the CVD method. As a result of applying this embodiment using the polishing apparatus shown in FIG. 4, the polishing time is about 1 for the combination of ceria abrasive grain # 10000 and diamond abrasive grain # 10000, compared to the conventional combination of diamond # 4000 and # 10000. The surface roughness was improved to 1/3.

  Similarly, a SiN film having a thickness of 200 nm is formed on the silicon substrate 10 by the CVD method, and the present embodiment is applied to the film removal at the peripheral edge of the substrate using the polishing apparatus shown in FIG. Compared to the conventional diamond # 4000 and # 10000 combination, the combination of ceria abrasive grain # 10000 and diamond abrasive grain # 10000 reduces the polishing time to about 3/4 and improves the surface roughness to 1/3. It was done.

(Second Embodiment)
5A and 5B are cross-sectional views showing a substrate processing process according to the second embodiment of the present invention, in which FIG. 5A shows a state in which a trench is formed, FIG. 5B shows a state before polishing of the substrate to be processed, and FIG. Indicates a state after polishing of the substrate to be processed. In the figure, 10 is a silicon substrate, 11 is a SiO ₂ film, 12 is a SiN film, and 13 is a needle-like protrusion of silicon.

As shown in FIG. 5A, the SiN film 12 and the SiO ₂ film 11 are sequentially deposited on the surface of the silicon substrate 10 by the LP-CVD method, and these are patterned to laminate the SiN film 12 and the SiO ₂ film 11. A hard mask made of a film is formed. Subsequently, using this hard mask, the silicon substrate 10 is etched by the RIE method to form a trench. At this time, etching disturbance occurs at the peripheral edge of the substrate, and mask residues and Si needle-like protrusions 13 are formed. Thereafter, the SiO ₂ film 11 is peeled off by wet etching.

FIG. 5B shows a state where the SiO ₂ film 11 is peeled off, and the SiN film 12 and the silicon needle-like protrusions 13 are generated at the peripheral edge of the silicon substrate 10. The polishing method of the present embodiment is applied to the removal of the silicon needle-like protrusions 13 including the SiN film 12 generated during the trench formation and the planarization of the substrate.

  Also in this embodiment, a polishing method in which the polishing tape 23a to which the ceria abrasive grain # 10000 is fixed and the polishing tape 23b to which the diamond abrasive grain # 10000 is fixed is applied. Using the polishing apparatus shown in FIG. 4, polishing was performed under predetermined polishing conditions, and finished as shown in the sectional view of the substrate to be polished shown in FIG.

  Here, when the removal of the SiN film 12 and the silicon needle-like protrusions 13 and the flattening of the substrate 10 were attempted only with the polishing tape 23a of ceria abrasive grains, the removal of the SiN film 12 progressed, but the removal of the silicon needle-like protrusions 13 progressed. Further, the progress of the planarization of the substrate is slow, and the removal of the silicon needle-like protrusions 13 is completed even if the polishing time is doubled compared to the combination of the diamond abrasive grain # 4000 and the diamond abrasive grain # 10000 of the prior art. There wasn't.

  On the other hand, when a polishing method in which a polishing tape 23a of ceria abrasive and a polishing tape 23b of diamond abrasive are combined is used, the polishing time is shortened to 2/3 as compared with the prior art, and the diamond grinding observed in the prior art. Polishing scratches due to grain # 4000 were eliminated, and the surface roughness was improved to 1/3. That is, in the case where it is necessary to remove the unnecessary silicon oxide film or silicon nitride film and to flatten the substrate, the combination of the ceria abrasive tape 23a and the diamond abrasive tape 23b is more effective. Will show.

  As described above, according to the present embodiment, the polishing tape 23a and the diamond abrasive grains to which the ceria abrasive grains are fixed are attached to the substrate to be processed on which the SiN film 12 and the silicon needle-like protrusions 13 are formed on the surface of the silicon substrate 10. By polishing using the fixed polishing tape 23b, the unnecessary film and the needle-like protrusions 13 on the peripheral edge of the substrate can be removed with high efficiency, and the accuracy of the polished surface can be improved. Therefore, the same effect as the first embodiment can be obtained.

(Third embodiment)
FIG. 6 is a cross-sectional view showing a substrate processing process according to the third embodiment of the present invention.

  This embodiment is an example applied to the removal of metal contamination at the peripheral edge of the substrate that occurs during the formation of a silicide of a metal film (Ni, Co, etc.).

  First, as shown in FIG. 6A, after a SiN film 12 is deposited on the silicon substrate 10, a resist film (not shown) is applied onto the SiN film 12, and photolithography is performed using this resist film as a mask. An opening is formed on the silicon substrate 10 by a technique.

  Next, as shown in FIG. 6B, metal (Co) is deposited by, for example, sputtering, and a metal film (Co film) 61 is formed on the SiN film 12 and the exposed portion of the substrate 10. Thereafter, by performing heat treatment, as shown in FIG. 6C, only the surface of the substrate Si exposed in the opening is reacted with metal to form a silicide film (CoSi film) 62. The unreacted metal film 61 is removed by etching or the like. At this time, if the resist film is not sufficiently applied to the peripheral portion of the silicon substrate 10, the substrate Si may be exposed at the peripheral portion when the opening is formed on the silicon substrate 10. When a metal film is deposited and heat treatment is performed with the substrate Si exposed at the peripheral edge, the silicon exposed at the peripheral edge reacts with the metal, and a metal film such as a silicide film and a reaction product of Si are formed. There is a problem that metal contamination occurs from the peripheral edge of the substrate 10.

  In order to prevent this metal contamination, it is desirable to remove the metal silicide film 62 and the SiN film 12 at the peripheral portion after the reactant such as a silicide film is formed. Here, the reason why the SiN film 12 at the peripheral edge of the substrate is removed is that the peripheral SiN film 12 becomes an obstacle when polishing the metal silicide film 62 at the peripheral edge of the substrate, as can be seen from FIG. . That is, if the SiN film 12 remains around the metal silicide film 62, polishing of the metal silicide film 62 utilizing the mechanical effect does not progress.

  The result of applying this embodiment to the removal of metal contamination generated at the peripheral edge of the substrate will be described. A polishing method in which the polishing tape 23a having the ceria abrasive grains fixed in the previous embodiment and the polishing tape 23b having the finishing diamond abrasive grains fixed thereon were combined was applied.

  Using the polishing apparatus shown in FIG. 4, the substrate 20 is adsorbed on the stage, the stage is rotated at a predetermined speed, and the polishing tape 23 (23a, 23b) is fed at a predetermined speed while the peripheral edge of the substrate. Polishing was performed by applying a predetermined pressure to the substrate and finished as shown in the cross-sectional view of the substrate in FIG. At this time, in addition to polishing using the mechanical effect by the polishing tape 23b, polishing using the chemical effect by the polishing tape 23a is performed in parallel, so that the SiN film around the metal silicide film to be removed is efficiently polished. Thus, the metal silicide film can be reliably removed by polishing.

  When a conventional combination of coarse diamond grains (# 4000) and finishing abrasive grains (# 10000) is polished under the same polishing conditions, the polishing time is reduced to 2/3, which is observed in the prior art. The rough abrasive grains were no longer scratched by diamond and the surface roughness was improved to 1/3. Here, the surface roughness was improved because diamond used only finishing abrasive grains and did not use coarse abrasive grains. In addition, the polishing time was shortened despite the fact that the diamond coarse abrasive grains were not used. By using the polishing tape 23a to which the ceria abrasive grains were fixed, the SiN film around the metal silicide film on the periphery of the substrate was removed. This is because it was efficiently removed by the chemical effect.

  In the present embodiment, an example in which a nitride film (Si nitride film system) is used as a mask material is shown, but an oxide film (Si oxide film system) may be used. Even if the oxide film or nitride film is formed after the silicide is formed to temporarily suppress metal contamination to other processes and then the oxide film or nitride film is removed together with the silicide film, the polishing time is shortened and the surface roughness is reduced. The effect of improvement is obtained.

(Modification)
In addition, this invention is not limited to each embodiment mentioned above. In the embodiment, SiO ₂ and SiN are shown as unnecessary films on the peripheral edge of the substrate. However, the present invention is not necessarily limited thereto, and can be applied to, for example, SiOC and SiCN. That is, the present invention can be applied to silicon oxide-based and silicon nitride-based films.

  In addition to silicon oxide films or silicon nitride films, materials difficult to polish and remove with ceria abrasive polishing tape, such as single crystal silicon, amorphous silicon, polysilicon, films in which impurities are introduced into these silicon films, carbon films When a metal film (tungsten, copper, aluminum, ruthenium, titanium, tantalum, hafnium, and compounds containing these materials) is polished and removed as an upper layer, a lower layer, or a mixed layer, such as diamond having the ability to mechanically polish and remove It is effective to combine abrasive grains.

  In the embodiment, ceria particles are used as abrasive grains having a chemical effect on a silicon oxide-based or silicon nitride-based film, but silica particles may be used instead of ceria particles. Furthermore, SiC particles may be used instead of diamond particles.

  In the embodiment, the fixed abrasive method using the polishing tape is described as the polishing using the abrasive mainly composed of the particles having the chemical effect. However, the abrasive particles are included in the contact surface between the polishing surface and the surface to be polished. It is good also as a loose abrasive grain system grind | polishing while supplying an abrasive | polishing agent. Furthermore, the polishing by the mechanical effect using diamond abrasive grains is not limited to the fixed abrasive grain system, and a free abrasive grain system may be employed.

  Specifically, as shown in FIG. 7, the non-woven fabric 72 fixed to the polishing head 71 is brought into contact with the peripheral portion of the substrate to be processed 20 adsorbed on the stage 21, and ceria particles or the like are formed in the vicinity of the periphery of the substrate 20. A polishing liquid containing abrasive grains containing as a main component may be supplied from the nozzle 73 to polish the peripheral edge of the substrate at the contact portion with the nonwoven fabric 72. Also in this case, the same effect as in the previous embodiment can be obtained by using polishing with diamond abrasive grains in combination. Here, the nozzle 73 supplies a polishing liquid containing abrasive grains mainly composed of particles having a chemical effect, and is not a chemical liquid that reacts with the substrate Si. Can be avoided.

  Further, in the embodiment, the example of polishing the bevel portion, which is a portion having a curved cross section at the end portion of the semiconductor substrate, has been described. However, a mark on alignment or a crystal on the main surface of the wafer is partially aligned around the substrate. It is also possible to apply to polishing of a notch portion provided for orientation recognition. Furthermore, the semiconductor substrate is not necessarily limited to Si, and other semiconductor materials can be used.

  In addition, various modifications can be made without departing from the scope of the present invention.

Sectional drawing which shows the substrate processing process concerning 1st Embodiment. The schematic block diagram which shows the polish device of the fixed abrasive system used for 1st Embodiment. Sectional drawing which shows the example of the polishing tape used for the grinding | polishing apparatus of FIG. The schematic block diagram which shows the other example of the polishing apparatus of the fixed abrasive system used for 1st Embodiment. Sectional drawing which shows the substrate processing process concerning 2nd Embodiment. Sectional drawing which shows the substrate processing process concerning 3rd Embodiment. The schematic block diagram which shows the grinding | polishing apparatus of the loose abrasive system concerning the modification of this invention.

Explanation of symbols

10 ... silicon substrate 11 ... SiO ₂ film 12 ... SiN film 20 ... abrasive tape 24 using the polishing tape 23b ... diamond abrasive grains using a substrate to be processed 21 ... rotation stage 22 ... motor 23 ... abrasive tape 23a ... ceria abrasive ... Polishing head 25 ... Pure water supply nozzle 31 ... PET film 32 ... Binder 33 ... Ceria abrasive grain 34 ... Diamond abrasive grain 61 ... Metal film (Co)
62 ... Silicide (CoSi)
71 ... Polishing head 72 ... Non-woven fabric 73 ... Polishing liquid supply nozzle

Claims (5)

Polishing the substrate by bringing a peripheral surface of the semiconductor substrate into contact with a first polishing surface on which abrasive grains mainly composed of particles having a chemical effect are fixed to a silicon oxide-based or silicon nitride-based film; ,
Polishing the substrate by bringing a peripheral surface of the substrate into contact with a second polishing surface on which abrasive grains mainly having a mechanical effect are fixed; and
A substrate processing method comprising:   The substrate processing according to claim 1, wherein the abrasive grains fixed to the first polishing surface are mainly composed of ceria, and the abrasive grains fixed to the second polishing surface are mainly composed of diamond or SiC. Method.   While rotating the substrate, both the first polishing surface and the second polishing surface are brought into contact with the peripheral portion of the substrate, and polishing by the first polishing surface and polishing by the second polishing surface are performed in parallel. The substrate processing method according to claim 1.   Rotating the substrate and polishing with the second polishing surface after polishing with the first polishing surface, or alternately polishing with the first polishing surface and polishing with the second polishing surface The substrate processing method according to claim 1. The periphery of the semiconductor substrate using a polishing liquid containing abrasive grains mainly composed of particles having a chemical effect on a silicon oxide-based or silicon nitride-based film, or in contact with a polishing surface on which the abrasive grains are fixed Polishing the part,
Polishing a peripheral portion of the substrate by using a polishing liquid containing abrasive grains mainly having a mechanical effect, or in contact with a polishing surface on which the abrasive grains are fixed;
A substrate processing method comprising:

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