TWI232541B - Aluminum hillock-free metal layer, electronic part, and thin flat transistor and its manufacturing method - Google Patents

Abstract

A kind of aluminum hillock-free metal layer and its manufacturing method are disclosed in the present invention. The compound film composed of aluminum neodymium alloy and aluminum is used as the metal layer, in which the aluminum layer is located on top of the aluminum neodymium alloy layer and the aluminum layer thickness is larger than aluminum neodymium alloy layer thickness. Thus, the formation of aluminum hillock can be suppressed effectively; and the manufacturing cost can be greatly reduced.

Description

1232541

[Technical field to which the invention belongs] The present invention relates to an aluminum wire layer, and the invention relates to a hillock-free gate, electronic components, and thin film transistors, and a manufacturing method thereof. . [Previous technology] In the semi-V system process, molybdenum (moybdenum, Mo) or Cr is generally used as the material of the metal layer. However, the expensive molybdenum or chromium metal will make the entire process cost high. No less. The most abundant metal on the earth, aluminum, is not only easy to obtain, but also cheap. It is usually used in metals. Choosing pure Shao as the material for the metal layer process has the following advantages: “Made in low air resistance coefficient” and good dependence on the substrate (substrate) also shows better etching characteristics . However, if pure aluminum having a melting point lower than that of a general metal is used as the metal layer ', there will be a problem of formation of aluminum spikes on the surface. Referring to Fig. 1A ', a schematic diagram showing metal deposition on a glass substrate is shown. First deposit the metal on the glass substrate at a lower temperature (about 150 τ). Therefore, the glass substrate 102 has crystal particles 104, and there are crystals between the crystal particles 104 and 104. The grain boundary 啰 J 〇6 is formed. Of course, the actual grains will not be as square as in Figure A. Here, for the sake of explanation, the crystal grains are neatly square. Then, “annealing” is performed, and the vibration of the crystal grains is increased by the thermal energy provided by the high temperature heating, so that the arrangement of the crystal grain atoms can be reorganized, and the crystal grains can be recrystallized by the disappearance of the crystals (recrysta 11 ine). After recrystallization

1232541 Case No. 92119085 said Amendment 5. The internal stress (in n e r s t r e s s) of the grains of the invention description (2) will decrease sharply due to the reduction of the defect row and defect density. If the tempering temperature continues to increase, so that the grains formed during the recrystallization stage have enough energy to overcome the surface energy between the grains, the grains will start to grow and consume in the process of consuming small grains. Larger grains and the grain boundaries of small grains are eliminated. At this time, the internal stress of the grains will be further reduced. When pure aluminum is used as the metal of the metal layer, there is a problem of small bumps. Please refer to Figure 1B, which shows a schematic view of tempered aluminum on a glass substrate. The high temperature of the tempering process causes thermal expansion of both aluminum grains 104 and glass substrates 102, but the thermal expansion coefficient of aluminum is greater than the thermal expansion coefficient of glass, which causes great stress on aluminum grains 104. compressive stress), since the aluminum system is adhered to the glass substrate 102, aluminum atoms grow along the grain boundary 106 and aluminum hillocks 110 are formed thereon. The aluminum spikes 11 formed on the metal layer not only cause unevenness in the thickness of other layers in the subsequent process, but excessive aluminum spikes 110 may pass through the insulating layer above the metal layer and cause A metal layer is in contact, causing a short circuit. The most common and most effective traditional practice is to add a few other higher melting elements to aluminum, such as “(Nd), titanium (Ti), hafnium (Zr), tantalum (Ta), silicon (Si) or copper ( Cu) to solve the above-mentioned problem of aluminum spikes. Please refer to Figure 2A, which shows the schematic diagram of the tempered aluminum alloy on the glass substrate. After the tempering (high temperature heating) of the aluminum alloy grains 204 on the glass substrate 202, the non-aluminum elements cannot be miscible with aluminum, so when the grains 204 grow, the non-aluminum elements will be transferred to Grain boundary 20 6 and aggregated into one in grain boundary 20 6

92082TW-correction.ptc page 51232541 V. Description of the invention (3) 丄:?, 2 0k These small particles 210 will block the channel of the grain boundary 2 06, so that the aluminum: when the boundary 206 grows, it cannot pass through the small Particles 21〇 and protruding out of the grain π # \ 方 七 and further suppress the shape of the sharp convex "° and pass the electron micrograph L々a 'i, the grain structure of the layer is more dense, and mixed with metal particles The gold layer 1 has a relatively loose grain structure with pores. Therefore, the rear: The thermal stress generated can be released through the loose junction of the chain alloy layer without pushing Shaoma; you can suffer from aluminum atoms to grow along the grain boundary 106 to become aluminum bumps h111. ck) 110. Among them, Japan's Kobeic 0 Neodymium Ul-Nd) alloy is the most well-known and widely used. Concentrated atom 3: large, high refining point, can effectively form particles in the grain boundary to prevent the atom from protruding from the channel of the grain boundary. When the temperature reaches about = w, no small bumps will be formed. However, 'Syringe is a rare gold, and it is Ή', and because of _d, a slow sputtering rate must be used to prevent splashing. More importantly, it has a high resistance value. The total resistance value is much higher than the pure name. According to the above, how to apply inscriptions to reduce costs in general semiconductor processes or metal layer processes of liquid crystal displays, but to prevent the generation of hU locks, is an important research goal for industry players. [Summary of the Invention] In view of this, the object of the present invention is to provide a metal layer without aluminum spikes and a method for manufacturing the same. A composite film composed of aluminum alloy and aluminum is used as the metal | Formation

1232541 V. Description of the invention ⑷ " Exposure to the sun " According to the purpose of the present invention, a metal layer without aluminum spikes and a manufacturing method thereof are proposed to avoid the occurrence of aluminum spikes. The metal layer is located on a substrate and includes at least two layers. Aluminum layer. An aluminum-alloy (Al-Nd) layer is first formed on the substrate; then an aluminum layer is formed over the aluminum-alloy layer. Among them, the thickness of the "aluminum alloy layer is in the range of about 100A to 4,000A" and preferably in the range of about 300A to 900A. The thickness of the aluminum layer is in a range of about 500 A to 4 500 A, and preferably in a range of about 1500 A to 3000 A. In order to make the above-mentioned objects, features, and advantages of the present invention more comprehensible, hereinafter, preferred embodiments are described in detail with the accompanying drawings as follows: [Embodiment Mode] The technical features of the present invention are applications Shaolu) alloy and Shao's composite film 'to suppress the generation of small bumps (hi 1 lock). Among them, the thickness of the Su layer is greater than that of the titanium alloy layer. The present invention is particularly applied to electronic components such as thin film transistors as its metal electrode layer. Please refer to FIG. 2, which illustrates a schematic diagram of an aluminum-alloy-aluminum composite film according to a preferred embodiment of the present invention. First, an aluminum-alloy (Al-Nd) layer 204 is formed on the substrate 202. Its film thickness ranges between about 100A and 4000A, and preferably between about 300A and 900A. Next, an aluminum layer 206 is formed over the aluminum-titanium alloy layer. Film thickness range

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1232541 I. V. Description of the invention (5) It is about 500 to 4500 people, and preferably about 150 to 300 people. And the thickness of the aluminum layer is greater than the thickness of the aluminum 'alloy layer. As for the film forming conditions for forming the Al-Nd layer 204 and the aluminum layer 206, there are no particular restrictions, and a general film forming pressure such as 0.3 Pa or 0.4 Pa can be used. The aluminum 'alloy layer 204 located under the aluminum layer 206 can release thermal stress in the subsequent interfacial process and effectively suppress the formation of aluminum spikes. In addition, a “protective layer that is not easily oxidized can be formed on the top layer 206”. Materials such as metallic molybdenum (MO), molybdenum nitride (MON), titanium (Ti), or alloy materials thereof (not shown in the figure) in). The following is a series of experiments for the composite membrane structure of the present invention, and the tempering temperature is 3 2 0. (: After the tempering time is about 10 minutes, use a scanning electron microscope (Scanning electron microscope) to observe the formation of sharp protrusions on the top layer. In addition, a molybdenum nitride layer (MoN) is formed on the composite film of the present invention. 'And check its profile (pr〇Hie check). Table 1 lists several experimental results of the present invention. ΗΐΠΗί Page 8 TW1106F (Chimei). Ptd 1232541 V. Description of the invention (6) The thickness of the alloy layer ( A) Thickness of aluminum layer (A) Check whether there is an aluminum tip bump profile after tempering. 0 2000 Fine 1800 0 No good 300 1000 No good 300 2000 No good 450 2000 No good 450 1000 Good 900 2000 No good 900 1000 No good 1800 2000 No good 1800 1000 No good

H (* Photo group) An aluminum layer was deposited on the substrate with a film forming pressure of 0.3 Pa, and its thickness was 2000 A. After a tempering temperature of 320 ° C and a tempering time of about 10 minutes, a scanning electron microscope (Scanning electron microscope) was used to observe whether there were aluminum spikes formed over the layer. Observation results show that when only the inscription layer is used, the inscription is protruded. Yi-Experiment. 2 (control group) An aluminum alloy layer was deposited on the substrate with a film forming pressure of 0.3 Pa to a thickness of 1800a. After a tempering temperature of 32 ° C and a tempering time of about 10 minutes, a scanning electron microscope (Scanning eiectfQn microscope) was used to observe whether aluminum spikes were formed on the aluminum 'alloy layer.

1232541 V. Explanation of the invention (7) Observation results show that · When only the aluminum-rhenium alloy layer is used, there is no indentation. In addition, a layer of metallic molybdenum (Mo) is formed on the aluminum 'alloy layer, and its thickness is 100 Å. A scanning electron microscope was used to examine the profile (prof i le check), and the results showed that the profile was very good. However, it is too expensive to use all aluminum alloys as the metal layer. In addition, the resistance value of aluminum's alloy is about twice that of aluminum, so it takes longer time to form a thicker film thickness to meet the requirements of component design. 3. Experiment 3 An aluminum alloy layer was deposited on the substrate at a film forming pressure of 0.3 Pa, with a thickness of 300 A; then, an aluminum layer was formed over the aluminum alloy layer to a degree of 2000 A. After the tempering temperature of 3200 ° C (tempering time of about 10 minutes, it was observed with a scanning electron microscope. The observation results were prominent. The sharp aluminum i: gold ΐ㈤m step was formed on another substrate to form a thickness The same # is 〇〇〇 °, but the thickness of the aluminum layer is halved to 1000 Α. After tempering, it is about 10 minutes after the temple is inspected with a scanning electron microscope. Inspection, & quot The results show: / Also no aluminum spikes are formed. After a, a layer of metal molybdenum (Mo) is formed over the aluminum layer of the two, and its thickness is 900A. The profile is checked with a scanning electron microscope (profile) check) 'The results show that the profiles of both are very good. Experiment 4

Page 10 TW1106F (Chi Mei) .ptd 1232541 Description of the invention (8) of the layer] ΐ = Γ, except that the thickness of the alloy layer is 45. … R de m. After tempering temperature 320. . Tempering time is about 10 minutes. Production: Microscope observation. Observation results show that there is no Shaojin Lutong! "Also 2 ί: an inscription alloy layer with a thickness of 45〇Α is also formed on the substrate, but the thickness of the aluminum layer is halved to 1,000 A. After tempering time is about 10 minutes Later, scanning with 4 ray j ^ i also showed that there was also no observing convex-type microscope observation. After observing the knot, a layer of metal molybdenum (M0) was formed over the aluminum layer of the two, and the bean 1 degree was 900 A. 。 And the scanning electron microscope to check its cross section (pr0fiie check), the results show that the two cross sections are very good. Experiment 5 The same two steps, except that the thickness of the aluminum titanium alloy layer is 900A, aluminum The thickness is 2000 A. After the tempering temperature is 3200c, and the tempering time is about 10 minutes, it is observed with a scanning electron microscope. The observation results show that no sharp protrusions are generated.

Similarly, an aluminum alloy layer having a thickness of 900 A was also formed on another substrate, but the thickness of the aluminum layer was halved to 1000 A. After tempering temperature 3 2 0. Alas, after a tempering time of about 10 minutes, it was observed with a scanning electron microscope. Observation results were not obvious: there were no sharp peaks. Then, a layer of metallic molybdenum (M0) was formed over the aluminum layer of the two, with a thickness of 900 A. The scanning electron microscope was used to check its profile (pr0 file check), and the results showed that the profile of both was very good.

1232541 V. Description of the invention (9) The same procedure as in Experiment 3, except that the thickness of the aluminum alloy layer is 1800A and the thickness of aluminum f is 2000a. After tempering temperature 3 2 0. (: After a tempering time of 10 minutes, observe with a scanning electron microscope. The observation results show that there are no aluminum spikes. ^ Similarly, an aluminum with a thickness of 1 8 〇 A is also formed on another substrate. "The gold layer", but the thickness of the Ming layer is halved to 丨 00〇A. After tempering temperature of 320 ° C 'tempering time of about 丨 0 minutes, observation with a scanning electron microscope. The observation results show that: Shao-convex formation. Then 'a layer of metallic molybdenum () was formed on the aluminum layer, with a thickness of 900a ° and the profile was checked with a scanning electron microscope (promifi check)' The results showed that the profile was very good From the above, it can be seen that plating an aluminum alloy alloy layer between the substrate and the aluminum layer can indeed effectively suppress the formation of aluminum spikes. In practical applications, a thinner aluminum alloy layer with a thinner film thickness can be used. The thickness of the aluminum layer is matched to reduce the production cost. Taking Experiment 5 as an example, an aluminum-titanium alloy layer with a film thickness of 450A and an aluminum layer with a film thickness of 2000A are selected. Two-thirds. In addition, | The resistance value is lower than that of aluminum 'alloy (only about one half), so the sheet resistance value of the A1N d / A1 composite film under the same film thickness condition is lower than that of the aluminum layer, so that the film thickness required for component design can be thinner , Not only reduces the coating time, but also reduces the total thickness of the product, and improves the flatness of the product.

ιϋΒ1 TW1106F (Chimei) .ptd Page 121232541 V. Description of the invention (10) The metal layer without aluminum spikes disclosed in the above embodiments of the present invention and the manufacturing method thereof have the advantages of effectively suppressing the generation of small protrusions, Compared with the traditional use of aluminum hafnium alloy alone, the cost is greatly reduced, and the production capacity is increased, which also has a positive effect on the reduction of components. The metal layer without aluminum spikes of the present invention can be applied to an electronic device as its electrode. In the following, a thin film transistor is taken as an example to illustrate the application of the present invention to form a metal gate electrode thereof. Fig. 3 is a schematic cross-sectional view of a bottom gate of a thin film transistor. First, a substrate 300 is provided, and a gate layer is deposited on the substrate 300, and the gate layer is patterned using lithography and etching techniques to form a gate 3 10. The gate layer is deposited as described above. A titanium alloy (AbNd) layer is deposited first, with a film thickness in the range of 100a to 4000A, and preferably in the range of 300A to 900A. between. Then, a film thickness ranging from about 500 A to about 450 A is deposited over the aluminum alloy layer, and preferably between about 1500 A to 3000 A. Next, a metal molybdenum (Mo) layer is deposited over the Shao layer, and the film thickness ranges between 300 A and 120 A. Next, a gate insulating layer 3 2 0 is formed over the gate 3 10. Then, an amorphous silicon layer 3 3 0 and an ohmic contact layer 340 are formed on the gate insulating layer 32 0 by a deposition, lithography and etching process. Next, 'a pole 360 and a source 365 are formed. The forming method is a step of depositing a metal layer, such as chromium, aluminum, and the like on the entire substrate 300, and patterning the metal layer by using a lithography and etching process. In the layer, an opening exposing the amorphous silicon layer 33 is formed.

The thirteenth TW1106F (Chimei) .ptd 1232541 Description of the invention (11) At this time, 'a / and pole 3 6 0 and a source 3 6 5 are also formed. Among them, the pole 3 6 0 and the source 3 6 5 are separated by a channel. ^ Then, a protective layer 370 is deposited on the entire substrate 300, and an opening is formed in the protective layer 37 through the lithography and etching steps to expose the drain 360. Finally, a transparent electrode layer 38o covers the protective layer 37o, and fills the openings exposed to the drain electrode 360. Similarly, the lithography and etching processes are used to pattern the transparent electrode layer 38. . Of course, the types of electronic components are very diverse, and there are many different processes for thin film transistors. The above is just one example, so the method of applying the present invention as a gate is not limited to the above. The electronic components manufactured by using the present invention not only greatly reduce the cost, but also effectively suppress the occurrence of small protrusions. The total resistance value is also positively beneficial compared with the traditional use of aluminum-titanium alloys. -'To sum up, although the present invention has been disclosed in the preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in this art can make various changes within the spirit and scope of the invention. Changes and modifications that depart from the scope of protection of the present invention should be defined as the scope of the attached patent application as follows:

1232541 Brief description of the drawings [Simplified description of the drawings] Figure 1A shows a schematic diagram of metal deposited on a glass substrate; Figure 1B shows a schematic diagram of tempered aluminum on a glass substrate; Figure 2 shows a diagram according to the present invention A schematic view of a composite film of aluminum-rhenium alloy aluminum according to a preferred embodiment; and FIG. 3 is a schematic cross-sectional view of a bottom panel of a thin film transistor. Explanation of reference numerals 102, 202, and 300: substrate 104 · crystal grain 106 · grain boundary 110: small bump (hi 1 lock) 2 0 4: titanium alloy layer 2 0 6 : I Lu layer 31 0 β · gate 3 2 0: Gate insulating layer 3 3 0: Amorphous silicon layer 340: Ohmic contact layer 3 6 0: Drain 3 6 5: Source 370: Protective layer 3 8 0 : Scope of patent application for transparent electrode layer

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Claims (1)

1232541 6. Scope of patent application 1. A metal layer (Hillock-free gate) without sharp edges is formed on a substrate to form at least two aluminum-containing layers. The metal layer includes: a: is titanium alloy (Al-Nd) layer on the substrate; and an aluminum layer on the aluminum 'alloy layer. 2. The metal layer according to item 1 of the scope of patent application, wherein the thickness of the aluminum layer is greater than the thickness of the aluminum 'alloy layer. 3. The metal layer according to item 1 of the scope of the patent application, wherein the thickness of the titanium alloy layer is between 100A and 4000A, and the thickness of the aluminum layer is between 50A and 4500A. 4. The metal layer as described in item 1 of the scope of the patent application, wherein the thickness of the aluminum alloy layer is preferably between about 300 A and 900 A, and the thickness of the coating layer is preferably about 150 A Between ~ 3000A range. 5. · A method for manufacturing a metal layer with no sharp edges to avoid the occurrence of uneven aluminum hi (lock), wherein the metal layer is located on a substrate and includes at least two aluminum layers, The manufacturing method includes the following steps: forming an aluminum 'alloy (A1-Nd) layer on the substrate; and forming an aluminum layer above the aluminum-titanium alloy layer; and the thickness of the edge layer is larger than the beryllium alloy layer Of thickness. 6. The manufacturing method as described in item 5 of the scope of the patent application, wherein the thickness of the formed alloy layer is in the range of 丨 00A ~ 400 0 A, and the thickness of the aluminum layer is in the range of 500A ~ 450 ° A range. 7. The manufacturing method as described in item 5 of the scope of patent application, wherein Page 161232541 6. The thickness of the aluminum-titanium alloy layer in the scope of the patent application is preferably between about 3 OO A and 9 OO A, and the thickness of the aluminum layer is preferably about 15 OOA. ~ 3 Ο Ο Ο A range. 8. The manufacturing method according to item 5 of the scope of patent application, wherein the film forming pressure for forming the aluminum 'alloy (A1-Nd) layer and the aluminum layer is about 0.3 Pa. 9. An electronic component comprising at least an electrode disposed on a substrate, wherein the electrode includes at least: an aluminum-rhenium alloy (A1-N d) layer disposed on the substrate; and an aluminum layer disposed on the substrate; Above the aluminum-titanium alloy layer; wherein the thickness of the aluminum layer is greater than the thickness of the aluminum 'alloy layer. 10. According to the electronic component described in item 9 of the scope of the patent application, the thickness of the aluminum alloy layer is in the range of 1000A to 400A, and the thickness of the aluminum layer is about 500 people. The range between 450 ° and 11 °. 11. The electronic component as described in item 9 of the patent application range, wherein the thickness of the aluminum alloy layer is preferably in the range of 300 A to 900 A. The aluminum The thickness of the layer is preferably in the range of 1500 A to 300 A. 12. The electronic component according to item 9 in the scope of the patent application, wherein the electrode further includes a protective layer disposed above the aluminum layer. 13. The electronic component according to item 12 of the scope of application for a patent, wherein the protective layer is selected from one of Mo (Mo), Indium Nitride (MoN), Chi (Ti), and alloy materials thereof. A thin film transistor element includes a substrate, and a gate layer is disposed on the substrate. A gate insulating layer, an amorphous stone layer, and an ohmic contact layer are sequentially deposited on the gate layer. There is a channel above the gate, and there are metal layers on both sides of the channel for TW1106F) .ptd Page 171232541 6. The scope of patent application is a source and an electrode, the source and the drain cover the ohmic contact layer and part of the substrate, and the source and the drain And covered with a protective layer, wherein the gate is characterized by: a Shao-Qin alloy (Al-Nd) layer and a Shao layer, wherein the aluminum layer is formed on the Ming-Yu alloy layer to suppress Shaojian The convexity is formed, and the thickness of the alloy layer is between about 00 A and 4000 A, and the thickness of the aluminum layer is between about 500 A and 4500 A. 15. The thin film transistor device according to item 14 of the scope of patent application, wherein the gate electrode further comprises a protective layer disposed above the aluminum layer. 16. The thin film transistor device according to item 15 of the scope of the patent application, wherein the protective layer is selected from one of molybdenum (Mo), molybdenum nitride (MoN), titanium (Ti), and alloy materials thereof. 17. An electronic component having a patterned electrode, wherein the electrode includes at least: an aluminum-alloy (Al-Nd) layer; and an aluminum layer disposed above the aluminum-alloy layer. 18. The electronic component as described in item 17 of the scope of patent application, wherein the thickness of the aluminum layer is greater than the thickness of the aluminum 'alloy layer.鬌 19. The electronic component as described in item 17 of the scope of patent application, wherein the thickness of the aluminum-titanium alloy layer is in the range of about 100A to 4000A, and the thickness of the aluminum layer is in the range of about 500A to 4500A. 20. The electronic component according to item 17 of the scope of the patent application, wherein the thickness of the aluminum alloy layer is preferably between about 300A and 900A, and the thickness of the aluminum layer is preferably about In the range of 1 500 A to 3 00 A. TW1106F (Chimei) .ptd Page 18 1232541 6. Scope of patent application 21. The electronic component as described in item 17 of the scope of patent application, wherein the electrode further includes a protective layer placed above the aluminum layer. 22. The electronic component according to item 21 of the scope of patent application, wherein the protective layer is selected from the group consisting of molybdenum (Mo), molybdenum nitride (MoN), titanium (Ti), and alloys thereof 〇 m TW1106F (Chi Mei) .ptd Page 19