TW591346B - Soft baking equipment for photoresist and method for forming a patterned photoresist - Google Patents

Abstract

A soft baking equipment for photoresist and method for forming a patterned photoresist is provided by adjusting the height of the pins disposed on the heater plate so as to fine tune the temperature of the soft baking process. In addition, a plurality of temperature controller precisely control a plurality of heating area of the heater plate respectively is also provided to proceed the soft baking process in an appropriate condition. In the case that the temperature of soft baking process can be fine tuned, the photoresist developed has the same critical dimension.

Description

591346 V. Description of the invention (2) The thin film transistor array is mainly formed by stacking a patterned conductive layer and a dielectric layer formed by a plurality of photomask processes. For example, the patterned conductor layer must be repeatedly sputtered into a film and photoresist in the production; it has soft baking, exposure, post-exposure baking, development, hard baking, etching, and photoresist peeling. . Among them, the mask process used to define the conductor layer mainly involves coating a photoresist liquid on a glass substrate (usually at the center of the glass substrate) on which the conductor layer is formed, and rotating the photoresist The liquid is evenly distributed on the glass substrate. Then the glass substrate is placed on a hot plate for soft baking, and after soft baking, exposure is performed, post-exposure baking, bulk, hard baking, etching, and light. Steps such as resistance peeling, etc., thus completing the production of the patterned conductive layer. Figure 1 shows a schematic diagram of a conventional soft baking using a photoresist soft baking device, and Figure 2 shows a key dimension of the pattern of the photoresist layer on the conventional glass substrate after development. And end point difference. First, please refer to FIG. 1. The conventional photoresist soft roasting device 100 is mainly composed of a heating plate 102 ° and a support pin 104. Among them, the supporting pin 〇 04 is disposed on the heating plate 〇 02 to support the glass substrate 106. In the process of soft baking " ', a glass substrate 106 is first provided. A photoresist layer 108 has been formed on the glass substrate 106, and then the glass substrate 106 is placed on a heating plate 1. The support pin 2 of 2 is turned on, and the photoresist layer 8 on the glass substrate 10 is heated by a heating plate 102. Since the support pin 104 on the heating plate 102 does not conduct heat, the photoresist layer 108 on the glass substrate 106 is heated by the heat radiation effect of the heating plate 102, so the glass substrate 1 The distance between 6 and the heating plate 102 will directly affect the soft baking temperature of the photoresist layer 108.

Page 6 591346 V. Description of the invention (3) Please refer to Figure 1 and Figure 2 at the same time. After soft baking, then perform an exposure process to transfer the ~ pattern on the mask to the light drop. Level 1 0 8. After that, the developing solution is sprayed on the glass substrate 106 in a developing direction 202 by the spraying device 200 in a scanning manner, and the developing solution sprayed on the glass substrate 106 will interact with the glass substrate 106. The photoresist layer 108 reacts to achieve the purpose of development. However, the reaction times of the developer and the photoresist layer 108 sprayed on the starting end 106a and the end end 106b of the glass substrate 106 are different, generally about 10 seconds. That is to say, the reaction time between the developer and the photoresist layer 108 at the starting end 106a is longer. The reaction time between the developer and the photoresist layer 108 at the end end 106b is shorter. Since the development time of the glass substrate 1 0 at the starting end 10 6 a is different from the developing end 10 6 b, the key dimension CD 1 of the pattern formed at the starting end 10 6 a is smaller than the ending end 1 6 6 b The key dimension CD 2 of the formed pattern. In the conventional technology, since the spraying of the developer is performed in a scanning manner, the difference in the reaction time between the developer and the photoresist layer is inevitable, so the key dimensions of the photoresist layer pattern are often different. In addition to the spraying direction of the developer solution, which affects the critical dimensions of the photoresist layer pattern, the uniformity of the photoresist itself in thickness during photoresist coating and the temperature distribution of the heating plate itself during the soft baking process will also affect the photoresist. The critical dimension of the layer pattern has a direct effect. However, the critical dimensional changes caused by the development process, the uniformity of the photoresist thickness, or the temperature distribution of the heating plate cannot be effectively overcome in the conventional technology. SUMMARY OF THE INVENTION In view of this, the object of the present invention is to provide a photoresist soft baking device and a method for forming a patterned photoresist layer, which can form the photoresist layer after development.

Page 7 591346 V. Description of the invention (4) The pattern has the same height difference between the heating plate and the multi-heating plate for supporting the above-mentioned layers for soft baking. The height difference is 4. Omm to 7. 0 0. 2mm 5.1. 2mm In this embodiment, the uniformity (unif mode) is thicker and taller, and the central support is applied to the thinner light in the light. Generally, the edges of the needles are gradually reduced by the support. One of the key purposes of the substrate needle is affected by the developing solution of the needle, the photoresist is softly placed > placed between support bases such as mm. Medium, branch ity), other parameters coating this book . The hot plate is designed to be sprayed on the south side of the resistance layer. After the completion of the height from the south side, the substrate is lined up at one end. The present invention proposes a light-baking device that can bake light on a substrate. This photoresist soft-baking device is mainly composed of two supporting pins on a heating plate. The support pins of the material have different heights, and the branch system is greater than 0.2 mm. When the height of the support pins is medium, the height difference of the support pins, for example, the height distribution between the support pins can be heated according to the thickness of the photoresist. The temperature distribution of the plate and the subsequent development process are taken into consideration. When the photoresist layer is near the center of the substrate, the height of the support pin can be designed to be middle. In other words, the height of the support pin is determined by the edge of the heating plate. Or, in accordance with the photoresist coating result, the height of the thicker area of the photoresist coating is higher than that of the photoresist, and the developing solution is along a developing side to the other side of the substrate. Therefore, this embodiment Can be high on one side and low on the other. In other words, one side of the hot plate is gradually reduced to the other side of the heating plate. If the heating plate is rotated with the developing direction as the axis, the action will also affect the key dimensions of the photoresist layer. For example, the height of the support pin can be designed as a corner.

Page 8 591346 V. Description of the invention (5) One corner of the board with high and other corners is gradually reduced to the height of the closing pin if the resistance layer of the heating plate itself is developed. A partial photoresist layer on the heating plate is developed after development. In this embodiment, it is between 140 degrees Celsius and in this embodiment. In order to achieve the above purpose, the light barrier is soft-baked, a heating plate, a plurality of high school temperature controllers (in t, the supporting pins are equipped with thermal blocks, and these are added to the heating temperature to control the temperature of the heating plate in the heating plate. Medium. The temperature is controlled so as to bake at different positions. In this embodiment, the temperature of the heating plate is increased by

Appearance. In other words, the height of the branch needle is heated by heating the other corners of the plate. "≫ Even if there is a difference in temperature or other factors that cause the size of the light key to change, this embodiment can also be adjusted by supporting the soft roasting temperature. In other words, this embodiment can adjust the height of the area of the support pin to Ensure that the critical dimensions are the same. The heating temperature of the heating plate is, for example, 70 ° C, and the preferred temperature is, for example, 10 1.5 ° C. The height of the support pin is, for example, between 4.0 mm and 7.0. In m, the present invention proposes another kind of photoresist soft roasting device on the substrate. The photoresist soft roasting device is mainly composed of supporting pins with equal degrees and a plurality of employment controllers arranged on a heating plate. Board, and the heating board can be divided into multiple heating blocks, which can be provided by the temperature controller without soft baking of different areas of the photoresist layer. In addition, the controller can be distributed in the adder corresponding to each heating block, for example. The temperature of each heating block is precisely controlled. The photoresist layer can be softened at the appropriate temperature. For example, one side of the hot plate can be increased to the other side of the heating plate by the control of multiple temperature controllers. ,or

Page 9 591346 V. Description of the invention (7) 1 06a, 3 0 6a: start end 1 1 6 b, 3 0 6 b: end end '108, 308: photoresist layer 200, 400: spraying device 2 0 2, 4 0 2: developing direction 3 0 6: base material 4 0 4: developing solution discharge direction 5 0 6: temperature controller- # CDl, CD2, CD3, CD4: MMK " tg The photoresist layer is made through photoresist coating, soft baking, exposure, post-exposure baking, development, and hard baking. Therefore, each process step may affect the key dimensions of the pattern. For example, in the process of photoresist coating, it is usually made on the substrate by spin on coating. If the thickness of the photoresist coating is not very uniform, it is very likely that The thickness of the pattern affects the critical size of the pattern. During the soft baking process, if the soft baking temperature of the photoresist layer is uneven at different positions, the critical size of the pattern will also be affected; and during the development process, However, the reaction time between the developing solution and the photoresist layer is directly related to the critical size of the pattern, so even the direction in which the developing solution is discharged may affect the critical size of the pattern. In this embodiment, the temperature control in the soft baking process is used to compensate for the above-mentioned key dimensional changes caused by different factors, thereby fine-tuning the soft baking temperature of the photoresist layer at different positions to control the photoresist. Layers in different- '

Page 11 591346 V. Description of the invention (8) The degree of conversion or solvent content in the position, so that after the photoresist layer is depleted in development, its pattern can have the same key size in different positions. FIG. 3 is a schematic flow chart of forming a patterned photoresist layer according to a preferred embodiment of the present invention. Referring to FIG. 3, the method for forming the patterned photoresist layer in this embodiment mainly includes the following steps: (a) providing a substrate; (b) forming a photoresist layer on the substrate; (c) light The resist layer is soft baked, and the soft baking temperature of the photoresist layer at different positions is controlled so that the solvent content or the degree of hardening of the photoresist layer changes with the position; (d) exposing the photoresist layer; and ^ and (F) developing the photoresist layer. In addition, in this embodiment, after the photoresist layer is exposed in step (d) and before the photoresist layer is developed in step (f), for example, a post-exposure bake step may be performed, and after the photoresist layer is developed in step (f), for example, Perform the φ one hard roast step. Please also refer to FIG. 3, when the developing solution is sprayed along the developing direction to achieve the developing purpose, this embodiment can control the soft baking temperature of the photoresist layer to increase from one side of the substrate to the other of the substrate. Side to avoid critical dimensional changes caused by spraying the developer in the developing direction. When the developing solution is sprayed along the developing direction to achieve the developing purpose, and the heating-plate is rotated with the developing direction as the axis to discharge the developing solution from one end of the substrate, this embodiment can control the soft baking temperature of the photoresist layer. Increment from one corner of the substrate to the other corners of the substrate to improve key dimension variations. When the thickness of the photoresist layer is not uniform, the soft baking temperature of the photoresist layer can be controlled to increase from the center of the substrate to the edge of the substrate to improve the variation of key dimensions. Or, in accordance with the photoresist coating result, adjust the height of the support pin so that the height in the thicker area of the photoresist coating is higher than the height in the thinner area of the photoresist coating. /

Page 12 591346 V. Description of the invention (9) The above-mentioned temperature control method is for illustration only, and it is not limited to the + embedding example is the above-mentioned three temperature control modes. After the disclosure, when the soft baking temperature distribution of the photoresist layer in a local area can be adjusted according to the process requirements, the following describes the implementation of the three temperature control modes in detail below. FIG. 4 is not a schematic diagram of soft baking by a photoresist soft-baking device according to a preferred embodiment of the present invention, and FIG. 5 is a photoresist layer process on a substrate according to a preferred embodiment of the present invention After development, the key dimensions of the pattern are approximately the same at the start and end. First, please refer to Figure 4, before soft baking, 'coat a photoresist layer 3 0 8 on the substrate 3 06, and then place the substrate 3 06 with the photoresist layer 308 on the photoresist soft Soft roasting is performed on a baking apparatus 300. In this embodiment, the photoresist soft roasting device 300 is mainly composed of a heating plate 300 and a plurality of support pins 300 of different lengths. Among them, the supporting pin 300 is arranged on the heating plate 300, and the height of the supporting pin 300 is, for example, increasing from the starting end 3 06 a to the ending end 3 06 b in the developing direction 40 2. In addition, the height difference of each adjacent support pin 304 is, for example, greater than 0.2 mm, and the height of each support pin 304 is, for example, between 4.0 mm and 7.0 mm. In this embodiment, the heating temperature of the heating plate 300 is, for example, between 70 ° C and 140 ° C, and the preferred temperature is, for example, 5 ° C. Since the support pin 304 on the heating plate 302 does not conduct heat, and the photoresist layer 3 0 8 on the substrate 3 is heated by the heat radiation effect of the heating plate 3 02, the photoresist layer 3 0 8 The soft roasting temperature will decrease along the developing direction 408 from the beginning 306a to the end 306b. In other words, after the soft baking process, the solvent content of the photoresist layer 3 0 8 adjacent to the starting end 3 6 a will be higher than that of the photoresist layer 3 0 6 adjacent to the end

Page 13 591346 V. Description of the invention (ίο) The photoresist layer 3 0 8 has a high or low solvent content, or the photoresist layer 3 at the starting end 3 6 a (the degree of hardening of A will be close to the end end 3 0 6 b The degree of hardening of the photoresist layer 308 is high. Then please refer to FIG. 4 and FIG. 5 at the same time, and then perform an exposure process to transfer the pattern on a photomask to the photoresist layer 308, and then use it later. In the scanning method, the developing solution is sprayed on the photoresist layer 3 0 8 through the spraying device 4 0 along the developing direction 4 2 to achieve the purpose of development. During the development process, the photoresist layer 308 is adjacent to each other. The degree of solvent content in the starting end 306a is low or the degree of hardening is high, so that the development speed of the photoresist layer 3 0 8 near the starting end 3 6 a is slower, and the photoresist layer 3 0 near the ending end 3 0 6 b. The development speed of 8 is fast. The difference in development speed can effectively compensate for the key size change caused by the difference in development time, so that the key size CD 3 of the photoresist layer 3 0 8 at the starting end 3 0 6 a will end with The critical dimension CD 4 of end 3 0 6 b is equivalent. Figure 6 shows a preferred embodiment according to the present invention. Schematic diagram of the structure of the photoresist soft roasting device. Please refer to Figure 4 and Figure 6 at the same time. After the development process is carried out, if the heating plate 3 2 is rotated with the developing direction 4 2 as the axis, the developing solution is transferred from the substrate. When 3 0 6 is discharged along the developer discharge direction 4 0 4, this action will affect the key size of the photoresist layer 3 0 8. Therefore, in this embodiment, the height of the support pin 3 0 4 is designed to be one corner high, other The corners are low. In other words, the height of the support pin 3 0 4 is gradually decreased from one corner of the heating plate 3 0 2 to the other corners of the heating plate 3 0 2. It is worth noting that the height of the support pin 3 0 4 The developing solution discharge direction is reduced by 4 0, and in the other direction, the height of the support pin 3 0 4 is increased along the developing direction 4 2. FIG. 7 shows a photoresist according to a preferred embodiment of the present invention. Soft roasting equipment

Page 14 591346 V. Schematic diagram of the description of the invention (11), and Fig. 8 shows the island in the I-I section in Fig. 7 in the light and ^ cause: Λ hot plate 3 0 2 The height of the support pin 3 0 4 is designed to be high in the middle and low in the edge. In other words, the height of the support pin 304 is intended from the center of the heating plate 302. Please refer to Figure 4, Figure 7, and Figure 8 at the same time. The photoresist layer 3 0 8 near the center of the substrate 3 06 may be slightly thicker than other areas due to process control, so this implementation Examples can be to the edge of the heating plate 3 02. Or, in accordance with the photoresist coating results, adjust the height of the support pins to make the height of the thicker areas of the photoresist coating thicker than that of the thin areas of the photoresist film. In addition to the above, if When the heating plate 3 0 2 itself has a temperature difference or other factors that cause the critical size of the photoresist layer 3 0 8 to change after development, this embodiment can also be adjusted by adjusting the height of the support pin 3 0 4. Fine adjustment of soft roasting temperature, and key dimensions after development are adjusted to be consistent. In other words, in this embodiment, the height of the support pins 3 04 in a local area on the heating plate 3 02 can be adjusted to ensure that the key dimensions of the photoresist layer 3 08 will be the same after development.

FIG. 9 is a schematic diagram of soft roasting by a photoresist soft roasting device according to another preferred embodiment of the present invention. Referring to FIG. 9, the photoresist soft-baking device 5 0 0 in this embodiment is mainly composed of a heating plate 5 2, a plurality of branch needles 5 0 4 having the same height, and a plurality of 5 5 The temperature controller 5 〇4. Among them, the 'support pin 5 〇4 is arranged on the heating plate 502, and heating, 502 can be divided into multiple heating blocks, and these heating blocks can provide a variety of different heating temperatures by the temperature controller 506. To soft bake different areas of the photoresist layer 308. In addition, the temperature controller in the heating plate 5 02

Page 15 591346 V. Description of the invention (12) 5 0 6 is corresponding to each; for example, ^ hot blocks are distributed in the heating plate 5 0 2. The temperature interpreter 5 0 6 can precisely control the temperature of each heating block of the U, so that the different positions of the photoresist layer 3 0 8 can be soft-baked at an appropriate temperature. In this embodiment, for example, the temperature may be increased from one side of the heating plate 502 to the other side of the heating plate 502 by control of multiple temperature controllers 506, or one of the heating plates 502. The corners are increased to other corners of the heating plate 502, and may also be increased from the center of the heating plate 502 to the edge of the heating plate 502. In summary, the present invention has at least the following advantages and features:-1. The present invention can fine-tune the soft baking temperature of the photoresist layer at different positions by adjusting the height of the support pin to control the photoresist layer at different positions. The solvent content or degree of hardening at the position _, so that after the photoresist layer is developed, its φ pattern still has the same key dimensions at different positions. 2. The present invention can use a plurality of temperature controllers in the heating plate to fine-tune the soft baking temperature of the photoresist layer at different positions to control the solvent content or the degree of hardening of the photoresist layer at different positions, thereby making the photoresist After the layer is developed, its pattern still has the same critical dimensions at different locations. 3. The present invention can improve the uniformity of the thickness of the photoresist, the temperature-distribution of the heating plate, the manner in which the subsequent development process is performed, or other key dimensional changes caused by other factors. Although the present invention has been disclosed as above with four embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications and retouching without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of the protection appeal shall be determined by the scope of the attached patent application.

P.16 591346 Brief description of the diagram. The first diagram is a schematic Λ diagram of the conventional soft roasting by a photoresist soft roasting equipment. The second diagram is a conventional development of a photoresist layer on a glass substrate. Then, the difference between the key dimensions of the pattern at the start and end points is shown in FIG. 3. FIG. 3 shows the process of forming a patterned photoresist layer according to a preferred embodiment of the present invention, and FIG. 4 shows the process according to the present invention. Schematic diagram of soft roasting by a photoresist soft roasting device in a preferred embodiment;

FIG. 5 shows that after the photoresist layer on the substrate is developed according to a preferred embodiment of the present invention, the key dimensions of the pattern are approximately the same at the starting end and the end; FIG. 6 shows that Schematic diagram of the structure of the photoresist soft roasting device of the preferred embodiment; FIG. 7 shows the structure of the photoresist soft roasting device according to a preferred embodiment of the present invention, and FIG. 8 shows I-I in FIG. 7 A cross-sectional schematic diagram of the cross section; and FIG. 9 is a schematic diagram of soft roasting by a photoresist soft roasting device according to another preferred embodiment of the present invention.

Page 17

Claims (1)

591346 6. Scope of patent application 1. A photoresist soft-baking device, suitable for inviting soft baking to a photoresist layer on a substrate, the photoresist soft-baking equipment includes: a heating plate; and a plurality of The supports are greater than 0 · 2 mm 2. As applied to the heating plate 3. As applied to the support pins 4. As applied to the support pins, the pins are arranged on the heating plate to support the substrate, and the needles have Different heights, and the difference in height of these support pins, please refer to the photoresist soft roasting device described in item 1 of the patent scope, where the heating temperature is between 70 degrees Celsius and 140 degrees Celsius. 0mm 之间。 The photoresist soft roasting device described in item 1 of the patent range, wherein the height is between 4.0 mm and 7.0 mm. Please refer to the photoresist soft-baking device described in item 1 of the patent, where the height is gradually reduced from one side of the heating plate to the other side of the heating plate 5. Others of the branches 6 · The edges of the branches. 7. The height of the branches 8. Soft roasting The photoresist soft roasting equipment as described in item 1 of the scope of patent application, wherein the height of the pin is reduced from one corner of the heating plate to the corner of the heating plate. The photoresist soft roasting device described in item 1 of the patent application scope, wherein the height of the pin is decreased from the center of the heating plate to the photoresist soft roasting device described in item 1 of the patent application range, The height of the support pin in the thicker area of the photoresist layer is higher than the thinner area of the photoresist layer. A photoresist soft baking device is suitable for feeding a photoresist layer on a substrate. The photoresist soft baking device includes : Page 18 591346 VI. Patent application scope A heating plate with a plurality of heating blocks, and these heating blocks can provide a plurality of different heating temperatures for soft baking the photoresist layer; and a plurality of supports The pins are arranged on the heating plate to support the substrate, and the supporting pins have the same height. 9. The photoresist soft roasting device according to item 8 of the scope of patent application, wherein the heating temperature provided by the heating area is between 70 ° C and 140 ° C. 10. The photoresist soft roasting device as described in item 8 of the scope of patent application, wherein the height of each of the branch needles is between 4. Omm to 7. Omm. 1 1. The photoresist soft roasting device as described in item 8 of the scope of the patent application, wherein the heating plate has a plurality of temperature controllers, and the temperature controllers are distributed in the heating plate corresponding to the heating blocks. 12. The photoresist soft roasting device as described in item 8 of the scope of the patent application, wherein the temperature of the heating plate is increased from one side of the heating plate to the other side of the heating plate. 1 3. The photoresist soft roasting device as described in item 8 of the scope of patent application, wherein the temperature of the heating plate is increased from one corner of the heating plate to other corners of the heating plate. 1 4. The photoresist soft roasting device according to item 8 of the scope of patent application, wherein the temperature of the heating plate is increased from the center of the heating plate to the edge of the heating plate. 15. A method for forming a patterned photoresist layer, including the following steps: providing a substrate; iii, page 19, 591346 6. The scope of the patent application is to form a photoresist on the substrate to soft bake the photoresist layer at a soft baking temperature so that the position of the photoresist changes; expose the photoresist layer; and This photoresist layer is developed. 16. The first method of applying the patent scope, wherein the soft baking temperature of the photoresist layer is transferred from one side of the substrate. 7. The first method of applying the patent scope, wherein the photoresist layer is softened. The baking temperature is from a corner of the substrate 1. As the first application method of the patent scope, the soft baking temperature of the photoresist layer is transferred from the center of the substrate to 19. As the first application method of the patent scope, The exposure of the photoresist layer includes a step 20 of post-exposure baking. For example, the first method of applying for a patent scope, wherein the photoresist layer is developed in step 0, and the position and position of the photoresist layer are not changed on the hard layer or the resist. The amount of light containing the agent to make solution •, control layer: the layer of the layer of the photoresistance plan described in the layer of light blocking the control system is baked on the soft side 1 other materials should be to the shape of the The layer described in the photoresistance plan. The blocking light angle should be controlled by other materials. Basically, it should be baked until the soft increase line is described in the plan of the photoresistive photoresistance plan. The shape of the cladding in the shape of 5 is more important than the photoresistance before the resist layer. Light and shadow Step roast Page 20