TWI247049B - Method for etching aluminum or aluminum alloy - Google Patents

Abstract

The present invention provides a method for etching aluminum or aluminum alloy, which is applicable on a process for producing a TFT LCD and comprises the following steps: providing a TFT substrate having an aluminum or aluminum alloy layer thereon; and performing a plasma etching on a high density plasma (HDP) etcher, such as induction coupling plasma etcher (ICP) or a transformer coupling plasma etcher (TCP), to etch a portion of the aluminum or aluminum alloy layer, in which the power or bias power of the plasma etching is smaller or equal to 2500W/(600x720)mm<2> substrate, thereby avoiding the formation of pollutant residue during the plasma etching process.

Description

1247049

FIELD OF THE INVENTION The present invention relates to a thin

Transistor, TFT) process, crystal process plasma: the remaining method. BACKGROUND OF THE INVENTION A film transistor (Thin Film, in particular, an improved thin film electric film transistor (TFT) can be used as a switching element in a liquid crystal display (LCD) or the like. The so-called thin film transistor panel (TFT叩(10) is transparent : A display element of an array is formed on the glass, and a TFT array is formed by using the film technology II as an integrated circuit. The manufacturing process is to perform various sputtering on the glass substrate by reverse sputtering.形成, photoresist coating, exposure, development, money engraving, photoresist stripping and ion implantation: sequence, stacking the lines and components to be fabricated layer by layer.

In the process of TFT LCD array, / after the metal aluminum or aluminum alloy (aluminum-bismuth alloy or aluminum-bismuth-copper alloy, etc.), the plasma is plasma-etched. ) Define the gate or wire pattern of the current aluminum or aluminum alloy etching, usually with chlorine (Cl2) as the main etching gas, with chloride, such as SiCl4, BC13, BBrs, CC14 as #刻辅佐' to improve aluminum etching Non-isotropic. The aluminum atom generates volatile aluminum trichloride (A 1C13) during the process of electric insects, and is extracted and removed. In order to achieve good contact with Ming or Ming alloy, the electric charge of the electric equipment is the reaction to the average. The state of the low-pressure reaction is maintained, thereby increasing the residual rate of the coating, and the etching product aluminum trichloride (aici3) can be quickly removed to prevent it from remaining on the semiconductor element.

1247049 V. INSTRUCTIONS (2) In the etching process of thin film transistor (TFT), the current aluminum or aluminum alloy is usually a high-density (HDP) etching machine, such as an inductive two-electrode plasma engraving machine ( ICP) or transformer coupled plasma etching machine (TCp). After forming a metal layer of aluminum or aluminum alloy on the TFT substrate, etching is performed in a high-density electro-converging machine to pattern the metal layer. ' ^ Referring to Figure 1, there is shown a schematic diagram of the configuration of a reaction chamber of a conventional high density etching machine. The TFT substrate 12 is normally placed on the electrostatic chuck of the lower electrode of the HDP-ICP etching machine, and is connected to the RF bias power supply 丨4. The inductive power supply 22 on the upper portion of the reaction chamber is connected to the induction coil 2〇, and is disposed above the upper electrode 18/in response, inducing self-biasing of the plasma ions dissociated by the plasma source 22 via the electrostatic chuck of the lower electrode. The plasma ion is attracted to form a plasma ring 16' to generate an ion bombardment effect, and the (four) effect is achieved. = When the aluminum or aluminum alloy is etched in the above TFT process, the high-density electric current = the sub-electrode is easily hit. The surface of the upper electrode 18 is usually covered with insulation. The ceramic material (CeraiD1C) or quartz (quartz). However, in the second degree of electricity, such materials will be subjected to long-term plasma ion impact and will be subject to residual reed (reSidUe) or particles, which contaminate the TFT f plate = surface: easy to reduce the process yield. In order to reduce the incidence of this situation, online people must increase preventive maintenance (PM) 仏 仏, 仏 4 mesh — ^ ^ ^ sheep review the damage of the upper electrode 18, and avoid affecting the process rate. However, too intensive pre-. , a low 71 ^ process efficiency, affecting the productivity of the etching machine

It is still another object of the present invention to provide an etching method for reducing the pre-expansion of the plasma etching machine and increasing its PM time interval. , an aluminum or aluminum alloy plasma preventive maintenance (Ρ Μ) times, according to an aluminum or aluminum step of the present invention, providing a substrate having a plasma etched thereon to etch a portion of the layered power supply and The bias power is less than the mm2 substrate. a Meng's money engraving method, including the following Cui Lu layer or aluminum alloy layer; and, in or alloy layer, wherein the electric erosion is equal to 2500W / (6 00 X U0) = Ming also provides - Xianyu alloy (4) Method - Thin film transistor (TFT) process for liquid crystal display, package 2 for providing a thin film transistor substrate, set iy _ _ _ _ ^ with a layer of inscription or aluminum screen - 咼 density plasma (HDP) Etching machine a Bu, 隹 - Emperor Jiang >, q, in the layer of Ming or Ming alloy, complex V will: two \ water: engraved with the etched part at or equal to 2. Just / (6GG x 72 two =, power: rate and bias power of small gas (Y and trichlorinated bri3), electropolymerization (four) pressure is about 3 can: today's film transistor (m) process or The etching method of the alloy includes the following steps: providing a layer of an inscription layer or an alloy layer deposited on the thin film transistor substrate; n:::r alloy layer ±; and, using the photoresist layer as a mask The electric power engraved to pattern the layer or the alloy layer, wherein the power and bias power of the electric engraving is less than or equal to 25 〇〇 [(6〇〇\ 72〇) 1247049 V. Invention description (4) -- -----------_ mm ^ bottom, finally, remove the photoresist layer to obtain a patterned aluminum layer or aluminum alloy layer as the gate or wire of the thin film transistor. The method provided by the invention can reduce the concentration of the engraved product generated by the plasma etching chamber: 4, and can be immediately evacuated to avoid the collision with the upper electrode to form a contaminant and remain on the thin film transistor substrate. In the above, the thin film transistor process yield is effectively improved. Embodiments Hereinafter, a thin film transistor fabrication process of a liquid crystal display is taken as an example, and the present invention is described in detail according to the present invention. The etching method of aluminum or aluminum alloy is not limited by the present invention. Referring to Figures 2A to 2E, the flow chart of the general thin film transistor is shown. First, as shown in Fig. 2A, on a transparent substrate 2 2 (such as 6 〇〇χ 720 mm2 transparent glass substrate), deposit a metal layer, such as aluminum or aluminum alloy (Al-Nb), molybdenum / aluminum - lanthanum (Al-Nd) alloy, aluminum - Titanium alloy, aluminum-stone-copper or titanium-aluminum-titanium, or one of tantalum nitride/aluminum alloy.) A photoresist with a gate une pattern is formed on the metal layer by a lithography process. The layer is plasma etched with the photoresist layer to form a gate line 2 〇 4. In a preferred embodiment, the plasma is etched in an inductively coupled plasma (ICP) #刻机 or transformer coupling Performing in a plasma (TCp) etching machine, such as

Tokyo Electron Ltd. (TEL)'s (FPD) series of TFTs for the use of plasma #刻机. According to the present invention, the power and bias power of the plasma etching machine is controlled to be less than or equal to 2500 W / (600 720 ft) mm2 substrate, preferably less than or equal to 200 0 W / (600 X 72 0) mm2 substrate. . In a better

0632-8573TWF(n); AU-91074; PEOGY.ptd Page 8 1247049 V. Invention Description (5) - In the embodiment, the power supply and bias power can be between 2 〇〇〇 and 15 〇〇 . If the membrane transistor substrate is larger than 600 X 720 mm2, its optimum power and bias power can be changed according to its area ratio. In order to obtain a good etching effect on aluminum or its alloy 7, the etching gas can be air gas (C12), and the flow rate is about 3 〇〇 to &lt; 225 Sccm / (6 〇〇 x 720 ) 2 . According to the etching effect, two gasification (B C I3 ) can be selectively added as one of the reaction gases, and the flow rate is controlled to be less than or equal to 100 sccm. The plasma etching pressure is between 3 and 5 mT 〇rr. The temperature of the upper, lower and side walls of the plasma reaction chamber can be controlled to 4 〇, and 6 (TC or so. 匕 By the above-mentioned residual method, the plasma power is controlled to be relatively low (less than or equal to 2500 or 20) 00W / (600 X 720 ) nun2 substrate), can effectively reduce the probability of plasma impact on the upper electrode of the plasma etching machine, while appropriately slowing the etching rate of aluminum, so that the etching product can be immediately extracted out of the reaction chamber, avoiding The formation of deposits contaminates the surface of the substrate, effectively improving the TFT process yield. Still refer to Figure 2A. After the plasma etching is completed, the photoresist layer is removed to complete the patterned aluminum metal or aluminum alloy gate line pattern 2〇4. A gate insulating layer 2〇6 is formed on the gate line 204, and the material thereof may be tantalum nitride. Then, as shown in FIG. 2B, an insulating layer 208 and a first semiconductor layer 210 are sequentially deposited on the transparent substrate 2〇2. For example, amorphous siiiCC n 'hereinafter referred to as a-Si) layer and second semiconductor layer 212, such as n +- doped amorphous silicon. Thereafter, the insulating layer 2〇8, the first semiconductor layer 210, and the second semiconductor layer 212 are defined to form an island-like structure as shown. Next, as shown in FIG. 2C, aluminum or Ming is deposited on the transparent substrate 202.

1247049 V. INSTRUCTIONS (6) Alloy layers, such as aluminum-sharp alloy (Al-Nb), molybdenum/aluminum-niobium (Al-Nd) alloy, aluminum-titanium alloy, aluminum-niobium-copper or titanium-aluminum-titanium Or one of tantalum nitride/aluminum alloy. Thereafter, the aluminum or aluminum alloy layer is defined by a lithography process to form a signal line 2 14 and a source/drain metal layer 2 18 and 2 2 0 as a wire or a conductor. The source/drain metal layers 21 8 and 220 are separated by a channel 216 and expose the first semiconductor layer 21 in the channel 216. According to the invention, the aluminum or aluminum alloy layer described above is patterned by plasma etching. In a preferred embodiment, the plasma etch can be performed in an inductively coupled plasma (ICP) etching machine or a transformer coupled plasma (TCP) etching machine.

Such as the TFTD of the FPD series of Tokyo Electron Ltd. (TEL)

The pulper engraved the machine. According to the present invention, the power and bias power of the plasma silvering machine is controlled to be less than or equal to 260 W/(6 00 X 720 ) mm 2 substrate, preferably less than or equal to 200 〇 W / ( 6 00 X 72 0 ) mm2 substrate. If the thin film transistor substrate is larger than 600 x 7 2 0 mm2, its optimum power and bias power can be converted according to its area ratio. In order to obtain a good money effect on aluminum or its alloy, the gas for the button gas can be chlorine gas (C12) at a flow rate of about 3 〇 2 2 2 5 sccm / (600 x 720) mm 2 . According to the remaining engraving effect, the three gasification shed (BCI3) can be selectively added as one of the reaction gases, and the flow rate is controlled to be less than or equal to 10 03 (^111/(6 0 0 \ 72 0 )1111112. The pressure is between 3~51^ Torr. The temperature of the upper plate, lower plate and side wall of the plasma reaction chamber can be 40t, 15 °C and 6 (TC or so. Work; then, as shown in Figure 2D, transparent Depositing a protective layer 2 2 2 on the substrate 2〇2, such as tantalum nitride, completely covers the TFT element to protect the element from external intrusion. Then a contact opening 2 2 is formed on the protective layer 22 2 4. Again

1247049 V. INSTRUCTION DESCRIPTION (7) Finally, as shown in FIG. 1E, an indium tin oxide layer (I Τ Ο ) is deposited on the transparent substrate 202 and is subjected to a micro-etching process to define it. It is a signal line area 226 and a pixel area 228. In the above embodiment, although the TFT substrate of 600×7 2 m m 2 is taken as an example, the present invention is not limited thereto, and a larger TFT substrate, for example, 680 X 880 mm 2 , 7 30 X 9 20 mm 2 . 1〇〇〇X i 2 00mm2 or 1 1 0 0 X 1 2 5 0mm2, etc., or a general semiconductor substrate, which can be used in the case of aluminum or aluminum alloy plasma cooking according to the present invention. Low power supply and low bias power to avoid impact on the upper electrode, and thus reduce the effect of the residue on the substrate. Experimental analysis, high-density (HDP) etching machine for aluminum or aluminum alloy, will be etched Both the power supply and the bias power are controlled to moderately slow down the "to the potential of the upper electrode of the money:: ^" while reacting outside the chamber to avoid opening, so that the etching product can be immediately pumped to the TFT process yield, and ~ The surface of the substrate is dyed on the surface of the substrate, effectively raising the time interval between the first and the first (M). When the time interval is evaluated, the most different 18 or the alloys are recorded. Evaluate the best plasma operating conditions. Page 11 0632-8573TlVF(n); AU.91 074;PEGGY.ptd 1247049 V. Description of invention (8) Rare-grain Al-Nd alloy with ICP money machine (Nd content 2 atoms ° bucket 4^ gas (sccm> power (W> pressure (mTorr) such as PM interval ( Slice &gt; Group 〆Cl2^ BC13^ Power ' Bias ^ 0^ 300- 2000^ 3400^ 3^ 200^ 200 wins 10CM 3000+ 300CM 5^ 50CM 270^ 90^ 300CM 3400 5^ 300~5 00^ 270 ^ 90^ 2000^ 2500^ 5^ 800^ 225—1 75^ 2000^ 2000^ 5^ 1000~1500# □ It can be seen from the first table that in the five plasma etching conditions, the number of PM spacers is grouped. The other is the largest, followed by the group 3. It shows that when the etching gas combination and pressure of the general etching aluminum or aluminum alloy are used, when the power supply and the bias power are reduced to 205 W or less, the number of PM pieces can be effectively increased. The time interval for performing PM is effectively elongated, which means that when the power and bias power of the plasma etching are lowered, the pollution caused by the upper electrode of the plasma etching can be effectively improved, and the line personnel can reduce the preventive property of the plasma etching machine. The number of maintenances and the quality of the process. Although the invention is disclosed above in the preferred embodiment, The scope of the present invention is defined by the scope of the appended claims, which is defined by the scope of the appended claims. quasi.

0632-8573TWF(n); AU-91074; PE〇jY.ptd Page 12 1247049 BRIEF DESCRIPTION OF THE DRAWINGS In order to make the above objects, features, and advantages of the present invention more apparent, the following The detailed description is as follows: Brief Description of the Drawings Fig. 1 is a schematic view showing the configuration of a conventional high-density plasma (HDP) etching machine reaction chamber. 2A to 2E are cross-sectional views showing a process for fabricating a thin film transistor according to an embodiment of the present invention. DESCRIPTION OF REFERENCE NUMERALS 10: electrostatic chuck, 12: TFT substrate, 14: RF bias power supply, 16: plasma pad, 18: upper electrode, 20: induction coil, 22: inductive plasma source, 202: TFT transparent substrate, 204 Gate line, 20 6 : gate insulating layer, 208: insulating layer, 210: first conductor layer, 212: second semiconductor layer, 2 1 4, signal line, 2 1 6 · channel, 2 1 8 2 2 〇: source/drain metal layer, 222: protective layer, 224: contact window, 226: signal region, 228: halogen region.

0632-8573TWF(n); AU-91074; PEGGY.ptd Page 13

Claims (1)

^47^9本u丨丨丨丨 The case of a product &quot;Bile 22960 / 〇月? G-day revision sixth, the scope of application for patent one - 1 - 'one &quot; 1 · an etching method of Ming or Ming alloy, comprising the following steps: providing a substrate having an aluminum layer or an aluminum alloy layer; A high-density plasma (HDP) etching machine performs a plasma etching to etch a portion of the aluminum layer or the aluminum alloy layer, wherein one of the plasma etching power and a bias power is less than or equal to 2 500 W / ( 6 0 0 X 72 0 ) mm2 substrate The U paste surname pressure is 3~5 m τ 〇rr, and the plasma engraved money is chlorine gas 'The flow rate of the plasma etching is 3〇〇 ~225sccm/(6 0 0 x 72 0)mm2. The method of etching an aluminum or aluminum alloy according to claim 1, wherein the substrate is a transparent glass substrate. 3. The etching method of aluminum or aluminum alloy according to item 2 of the patent application scope, wherein the aluminum alloy is aluminum-bismuth alloy, aluminum-titanium alloy, aluminum-bismuth alloy, chain-stone-copper or titanium-aluminum - one of titanium, or tantalum nitride/aluminum alloy. 4. The etching method of aluminum or aluminum alloy according to claim 1, wherein the power source and the bias power are less than or equal to 2000 W/(600 x 72 0 ) mm 2 of the substrate. 5 - a method for engraving aluminum or aluminum alloy, comprising the steps of: providing a substrate; depositing an aluminum layer or an aluminum alloy layer on the substrate; forming a patterned photoresist layer on the aluminum layer or And on the aluminum alloy layer, and using the photoresist layer as a mask, performing a plasma etching to pattern the aluminum layer or the aluminum alloy layer, so that one of the plasma etching power and a bias power Less than or equal to 2 5 0 01/(600/ 720)11111]2 substrate, the plasma money engraved 0632-8573twf2(3.7) ; AU91074 ; wayne.ptc Page 14 1247049 __ Case No. 91922960 ^ ! 曰 Amendment _ 6. The reaction gas of the patent application scope contains chlorine gas (Ci2), flow rate is 30 0~225sccm/(600x 720 Between the mm2 substrates, the plasma surface grinding force is between 3 and 5 ffl T rr; and the photoresist layer is removed. 6. The etching method of aluminum or aluminum alloy according to claim 5, wherein the power source and the bias power are less than or equal to 200 0 W/(600 x 720) mm 2 of the substrate. 7 · According to the application for patents, the fifth item of the household name, or the alloy of the chain, the method of the alloy is Ming-hammer alloy, Ming-Xu alloy, chain_titanium alloy, aluminum-shixi-copper or One of titanium-aluminum-titanium or tantalum nitride/aluminum alloy. 8. The method of engraving aluminum or aluminum alloy according to claim 5, wherein the plasma etching is performed on an inductively coupled plasma (丨Cp) etching machine or a transformer coupled plasma (TCP) etching machine. Conducted in one of the stations. 9. The engraving method of aluminum or aluminum alloy according to item 8 of the patent application scope, wherein the induction electro-mechanical (ICP) instrument or the transformer light-man + plasma (TCP) machine is a liquid crystal display film A special machine for crystals: package 1 0. The method of surface aluminum or aluminum alloy according to claim 5, wherein the patterned aluminum layer or aluminum alloy layer is used as a gate or wire of a body. ', private day 0632-8573twf2 (3.7); AU91074 ; wayne.ptc 麓