JPH04298017A - Method and device for stabilizing temperature in developing device or wet etching device - Google Patents

Abstract

PURPOSE:To carry out surface temperature control of a wafer and a mask accurately and readily and to stabilize a temperature thereof in a resist pattern developing device and a wet etching device. CONSTITUTION:A device is composed of circulation solution which heats and cools a substrate holding stand 4 for holding a processing substrate 1 such as a wafer and a mask, a means 2 for detecting a surface temperature of the processing substrate 1 which is held on the substrate holding stand 4, and means 6, 7 for controlling a surface temperature of the processing substrate 1 to be inside a specified allowable temperature range by controlling a temperature and flow rate of circulation solution based on a surface temperature which is detected by the surface temperature detecting means 2.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a developing device for forming a resist pattern when manufacturing high-density integrated circuits such as LSIs and VLSIs, or photomasks used for manufacturing the same, and a developing device for forming a resist pattern. The present invention relates to a method and apparatus for stabilizing temperature in a lithography apparatus such as a wet etching apparatus through a resist pattern.

0002

2. Description of the Related Art In recent years, demands for higher performance and higher integration of semiconductor integrated circuits and the like have been increasing. Therefore, efforts are being made to establish ultra-fine pattern processing technology by lithography using electron beams, soft X-rays, ion beams, etc. in place of conventional photolithography using ultraviolet rays.

[0003] Currently, spray, paddle, and dipping methods are used in the developing process and the rinsing process, which are the processes for forming fine resist patterns. In addition, a method similar to the above is also used in wet etching, which is a process during photomask manufacturing. FIG. 3 shows a schematic configuration of an example of a conventional developing device for performing development and rinsing. In the figure, the apparatus includes a developer tank 12, a substrate holder 4 that penetrates the bottom of the tank 12 and is rotatably and watertightly attached by an O-ring 9, a motor 5 that rotates the substrate holder 4, and a developer supply pipe 3. and a spray nozzle 8 for supplying a rinsing liquid, the wafer or mask 1 fixed on the substrate holding table 4 is transported from the developer supply pipe 3 to the developer tank 1.
Developed with the developer supplied in 2, and after development was completed,
Rinsing is performed using a rinsing liquid sprayed from a rinsing liquid supply spray nozzle 8.

By the way, temperature control in these steps involves controlling the temperatures of the developing solution, rinsing solution, etching solution, etc., the temperature of the wafer and mask before development or etching, and
This is done by controlling the environmental temperature of the developing or etching equipment, and the temperature is also stabilized by flowing constant temperature water through supports such as wafer and mask spinners. However, direct surface temperature control of the wafer and mask is not performed.

[0005]

[Problems to be Solved by the Invention] In order to make ultra-fine lithography technology possible, the exposure precision required of ionizing radiation exposure equipment has become stricter, and the resist process has also become very important. In particular, temperature control during development is important; unless the temperature is kept constant, the desired resist pattern cannot always be obtained. From this, it can be said that no matter how much the precision of the ionizing radiation exposure apparatus improves, unless the precision of the resist process improves, the precision of the resulting resist pattern will not improve. However, in the development of these fine patterns, as mentioned above, only the temperature control of the developer and rinsing solution and the seasoning of the wafer or mask before development are performed, and the wafer or mask during development and rinsing is There is no direct surface temperature control of the mask.

[0006] Also, wet etching of chromium, etc. during photomask manufacturing is similarly not sufficiently temperature controlled. In particular, etching uses a chemical reaction,
It can be said that temperature control of the mask surface is important.

The present invention has been made in view of the above circumstances, and its object is to provide a developing device for forming a resist pattern including an ultra-fine pattern, and a wet etching device for using the formed resist pattern. It is an object of the present invention to provide a method and apparatus for accurately and easily controlling the surface temperature of a wafer or mask and for keeping the temperature constant.

[0008]

[Means for Solving the Problems] During the operation of a developing device used for developing and rinsing an exposed wafer or mask, or an etching device used for etching the exposed wafer or mask, the surface temperature of the wafer or mask is It does not become constant due to reactions inside and vaporization of the processing liquid.

For this reason, in the method of stabilizing the temperature of a processed substrate such as a wafer or mask in a developing device for developing and rinsing for forming a resist pattern or a wet etching device for forming a resist pattern according to the present invention, By heating or cooling the substrate holder that holds the substrate during , rinsing, or wet etching operations, the surface temperature of the substrate to be processed can be directly controlled to a predetermined temperature. Accuracy can be improved.

For this purpose, for example, a temperature-controlled liquid such as water is caused to flow inside the substrate holding table at a controlled flow rate. In addition, while monitoring the surface temperature of the substrate to be processed held on the substrate holder, the monitored surface temperature
It is desirable to control at least one of the temperature and flow rate of the liquid so that the temperature falls within an allowable temperature range for rinsing or etching.

Further, the temperature stabilization device for a substrate to be processed such as a wafer or a mask in a developing device for developing and rinsing for forming a resist pattern or a wet etching device for forming a resist pattern according to the present invention is suitable for stabilizing the temperature of a substrate to be processed such as a wafer or a mask. means for heating and cooling a substrate holding stand that holds the substrate holding stand; means for detecting the surface temperature of the processed substrate held on the substrate holding stand; and means for heating and cooling the substrate holding stand that holds the substrate holding stand; The method is characterized by comprising means for controlling the cooling means so that the surface temperature of the substrate to be processed falls within a predetermined allowable temperature range.

[0012] In this case, the heating and cooling means comprises a device for heating or cooling liquid such as water and flowing it in an adjustable flow rate inside the substrate holding table, and the surface temperature control means adjusts the surface temperature detected by the surface temperature detection means. It is desirable to adjust at least one of the heating or cooling temperature of the liquid and its flow rate based on the above-mentioned conditions, and furthermore, it is desirable that the surface temperature detection means comprises an infrared surface temperature measuring device.

[0013]

[Operation] By using the method and apparatus of the present invention, changes in the surface temperature of the wafer or mask due to extrinsic temperature changes and intrinsic temperature changes during development, rinsing, or etching can be suppressed, and resist By eliminating temperature dimensional changes in the pattern or etching pattern, fine patterns can be accurately and stably obtained, and the effect on throughput can be eliminated.

[0014] Also, unlike the case of simply flowing a constant temperature solution, it is possible to monitor the surface temperature using infrared rays and change the temperature and flow rate of the circulating fluid based on this, thereby responding to sudden temperature changes.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below based on the illustrated embodiments. FIG. 1 shows an embodiment of an apparatus for developing and rinsing using the method of the present invention. FIG. 4(a) is a sectional view thereof, FIG. 2(b) is a sectional view showing a developing step, and FIG. 4(c) is a sectional view showing a rinsing step. Further, FIG. 2 shows a resist pattern forming process. Components in FIG. 1 that are similar to those in FIG. 3 are given the same reference numerals.

As shown in FIG. 1(a), the device of this embodiment, like the conventional device shown in FIG. It has a watertightly attached substrate holding table 4, a motor 5 for rotating the substrate holding table 4, a developer supply pipe 3, and a spray nozzle 8 for supplying a rinse liquid. The difference from the conventional example shown in FIG. 3 is that the circulating liquid is configured to flow within the substrate holding table 4. The arrow in the figure indicates the direction of flow of this circulating fluid. As shown in the figure, an O-ring 9 is provided at a position that allows rotation of the circulating fluid flow path. The flow rate and temperature of this circulating fluid are controlled by directly measuring the surface temperature of the wafer or mask 1 using an infrared surface temperature measuring device 2. This control is performed by a computer 6 and a circulator 7 with a heating/cooling device. That is, the detected temperature signal from the infrared surface temperature measuring device 2 is input to the computer 6, and the computer 6 controls the heating/cooling device and sends out the circulation from the circulator 7 so that the surface temperature is within a predetermined allowable temperature range. Control the flow rate of liquid. For example, if the surface temperature is too high, the heating/cooling device is controlled in the direction of cooling, and if the surface temperature is too low,
Control the heating cooler in the direction of heating. If the treatment liquid only generates heat or absorbs heat, the cooling/heating device may be configured to perform either cooling or heating. Further, if the deviation from the target temperature is large, the flow rate of the circulating fluid sent out from the circulator 7 is increased, and if the deviation is small, the flow rate is decreased. The above is one form of control; alternatively, the flow rate may be kept constant and the temperature of the circulating fluid may be controlled to keep the surface temperature constant.

Next, using the apparatus of this embodiment, in particular,
The process of forming a resist pattern on the wafer 1 will be explained with reference to FIG. In addition, in the following explanation,
HEMT using GaAs wafer as wafer 1
(High electron mobility transistor: High Elect
ron Mobility Transistor)
A case will be described in which a gate pattern of a device is developed by a dipping method.

First, before explaining the development process, the electron beam lithography process for forming the resist film 13 on the wafer 1 and forming the resist pattern will be explained. As shown in FIG. 2(b), a positive resist (trade name: Tokyo Ohka Co., Ltd.) containing polymethyl methacrylate as a main component is applied to the upper surface of the GaAs wafer 1 as shown in FIG.
Coat OEBR-1000) with a spinner. After coating, bake at a temperature of 170°C for about 30 minutes until the film thickness is 0.
．． A resist film 13 of 5 μm is formed.

Next, as shown in FIG. 3C, in order to form a gate pattern with a width of 0.3 μm on the resist film 13, a predetermined portion of the resist is etched using the electron beam 14 of the electron beam lithography system. The film 13 is altered in quality. A resist pattern is obtained from this altered resist film portion 15.

After the resist pattern is drawn by the electron beam 14, the drawn resist pattern is developed using the developing device shown in FIG. 1(a). That is, the wafer 1 on which a resist pattern has been drawn using the electron beam 14 is fixed to the substrate holding table 4 of the apparatus. Then, the developer 11 is supplied from the developer supply pipe 3.
supply. The developer 11 is as shown in FIG. 1(b). This developer 11 is a mixed solution of methyl isobutyl ketone and isopropyl alcohol at a mixing ratio of 1:3 at about 23°C. The resist film portion 15 that has changed in quality during development is dissolved in the developer 11, and heat of dissolution is generated. Normally, this heat generation would have a large effect on the line width. However, since the surface of the wafer 1 is kept at a constant temperature by the temperature and flow rate of the circulating liquid flowing through the substrate holding table 4, development can always be performed under constant conditions, and the line width becomes precisely constant. A developing process is performed by immersing the wafer 1 in the developer 11 for 5 minutes.

After the development is completed, as shown in FIG. 1(c), the substrate holding table 4 is raised and the used developer 11 is discharged from a developer discharge port (not shown). At the same time as the developer 11 is discharged, the rinse liquid 1 is discharged from the rinse liquid supply spray nozzle 8.
0 is sprayed onto the wafer 1 and rinsed for 30 seconds. At this time, the sprayed rinse liquid 10 causes vaporization heat absorption, and this heat absorption affects the developed line width. In particular, this heat absorption lowers the temperature of the developer tank 12 itself, which affects the next development. However, since the temperature of the surface of the wafer 1 is kept constant as described above, this influence can be eliminated according to the present invention. After rinsing, Figure 2
A resist pattern as shown in (d) is formed on the wafer 1.

As described above, according to the developing device of this embodiment, even if the resist film portion 15 altered in quality by electron beam lithography melts and heat of dissolution is generated, the circulating fluid is constantly circulating and the surface of the wafer 1 is temperature is kept constant. In addition, even if the developing area is large and the amount of heat generated is large, the surface temperature is monitored by an infrared surface temperature measuring device 3 installed above the substrate holding table 4, and in order to keep the temperature constant, a circulating fluid is used. This is handled by changing the temperature and flow rate. In the rinsing process as well, the sprayed rinsing liquid 10 vaporizes and absorbs heat, but since the temperature of the surface of the wafer 1 is similarly controlled, there is no effect from temperature changes. In addition, this heat absorption lowers the temperature of the developer tank 12 itself, which has a large effect on the time until the next development. However, since the temperature of the surface of the wafer 1 is always constant, even changes in the ambient temperature do not affect development. There is no.

The temperature stabilization method and apparatus of the present invention have been described above regarding the developing device for developing and rinsing.
The temperature stabilization method and apparatus of the present invention can also be applied to a wet etching apparatus having a configuration substantially similar to that shown in FIG. Note that the present invention is not limited to these embodiments and can be modified in various ways. For example, the temperature of the substrate holding table 4 may be controlled by another heating/cooling device that does not use circulating fluid.

[0024]

As described above, according to the temperature stabilization method and device for a developing device or a wet etching device of the present invention, the wafer is Alternatively, it is possible to suppress changes in the surface temperature of the mask, eliminate dimensional changes in resist patterns or etched patterns, and accurately and stably obtain fine patterns.
Moreover, the influence on throughput can be eliminated.

[0025] Also, unlike the case of simply flowing a constant temperature solution, it is possible to monitor the surface temperature using infrared rays and change the temperature and flow rate of the circulating fluid based on this, thereby responding to sudden temperature changes.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of a wafer developing apparatus according to the present invention, in which (a) is a cross-sectional view thereof, (b) is a diagram showing a developing process, and (c) is a diagram showing a rinsing process.

FIG. 2 is a diagram for explaining a resist pattern forming process.

FIG. 3 is a diagram showing an example of a conventional developing device.

[Explanation of symbols]

1...Wafer or mask 2...Infrared surface temperature measuring device 3...Developer solution supply pipe 4...Substrate holding stand 5...Motor 6...Computer 7...Circulator with heating/cooling device 8...Spray nozzle for rinsing liquid supply 9...O-ring 10...Rinse liquid 11...Developer 12...Developer tank 13...Resist film 14...Electron beam 15... Altered resist film part

Claims (6)

[Claims] 1. A method for stabilizing the temperature of a substrate to be processed, such as a wafer or a mask, in a developing device that performs development and rinsing for forming a resist pattern or a wet etching device using a resist pattern, comprising the steps of developing, rinsing,
Alternatively, a temperature stabilization method is characterized in that the surface temperature of the substrate to be processed is directly controlled to a predetermined temperature by heating or cooling a substrate holder that holds the substrate to be processed during a wet etching operation. 2. A surface temperature of the substrate to be processed is directly controlled to a predetermined temperature by flowing a temperature-controlled liquid such as water into the substrate holding table at a controlled flow rate. 1. The temperature stabilization method described in 1. 3. While monitoring the surface temperature of the substrate to be processed held on the substrate holder, at least one of the temperature and flow rate of the liquid is adjusted so that the monitored surface temperature falls within a predetermined allowable temperature range. 3. The temperature stabilization method according to claim 2, further comprising controlling the temperature. 4. A device for stabilizing the temperature of a substrate to be processed such as a wafer or a mask in a developing device for developing and rinsing for resist pattern formation or a wet etching device for forming a resist pattern, in which the substrate to be processed is held. a means for heating and cooling a substrate holding table; a means for detecting a surface temperature of a substrate to be processed held on the substrate holding table; and a means for heating and cooling the substrate holding table based on the surface temperature detected by the surface temperature detecting means. 1. A temperature stabilizing device comprising means for controlling the surface temperature of a substrate to be processed so as to be within a predetermined allowable temperature range. 5. The heating and cooling means comprises a device that heats or cools a liquid such as water and causes it to flow inside the substrate holding table in an adjustable flow rate, and the surface temperature control means controls the surface temperature detected by the surface temperature detection means. 5. The temperature stabilizing device according to claim 4, wherein at least one of the heating or cooling temperature of the liquid and its flow rate is adjusted based on the temperature. 6. The temperature stabilizing device according to claim 4, wherein the surface temperature detecting means comprises an infrared surface temperature measuring device.