JPH03215867A - Developing processing method for positive resist - Google Patents

Abstract

PURPOSE:To eliminate dust attracted by electrostatic charge and to form a clean resist pattern by cleaning a substrate to be processed after it is developed with the aid of immersing it in rinse liquid made by mixing pure water and alcohol. CONSTITUTION:The substrate to be processed 1 coated with positive resist is set on the rotating stage 2 of a developing processing device after it is selectively exposed by a reduction exposure device and statically developed by alkaline solution (developer). Next, the liquid obtained by mixing the pure water and the isopropyl alcohol is made to flow from a rinse liquid nozzle 5 while rotating the substrate 1. Then, the substrate 1 is spun and dried by accelerating the revolving speed of the stage 2. At this time, the pure water where the isopropyl alcohol of 10% is mixed is used as the rinse liquid. By this developing processing method, the dust on the pattern is eliminated and the dust is hardly attached thereafter. Besides, the fine pattern is formed with high accuracy. As a result, this method is made useful for improving the yield and the quality of a semiconductor device.

Description

[Detailed Description of the Invention] [Summary] Regarding the improvement of the rinsing process after development, the purpose of forming a processed substrate surface with a clean resist pattern with less dust is to use a processed substrate coated with a body resist. In the development processing method of selectively exposing, developing and rinsing, the substrate to be processed after development is stopped and washed using a rinsing solution containing a mixture of pure water and alcohol. shall be.

[Industrial application field]

The present invention relates to an improvement in post-development rinsing in a positive resist development process.

Lithography technology is used heavily in the manufacturing process of semiconductor devices, and the development and rinsing processes in the lithography technology are also extremely important for high-precision patterning.

[Conventional technology]

Lithography technology involves applying a resist onto a substrate (wafer) to be processed, selectively exposing it to a predetermined pattern, developing it, and then rinsing it with a rinsing solution;
Then, development is stopped and washed to form a resist pattern. Recently, automated processing has been carried out to improve efficiency, and this is a single-wafer processing system that processes each substrate one by one.

Therefore, a single-fed type is used for the developing process, and the first
The figure shows a schematic diagram of the main parts of a developing processing apparatus (developer). Symbol 1 in the figure is the substrate to be processed. Reference numeral 2 designates a rotation stage that rotates by chucking (vacuum suctioning) the substrate to be processed, 3 a cover, 4 a developing solution nozzle, and 5 a rinsing solution nozzle.

The developing device shown in the figure is called a rotary paddle developing device that can be rotated and stopped, and has a structure that has been widely used recently.The developing processing method thereof will be explained below.

(2) Chucking the substrate 1 to be processed onto the rotation stage 2.

(2) While rotating the substrate 1 to be processed, the developer is dripped onto the surface of the substrate to be processed from the developer nozzle 4 located at the center of the substrate to be processed, so that the developer is applied onto the surface of the substrate to be processed.

■Hold it in a still state for about 1 minute.

(2) Next, the substrate 1 to be processed is rotated again and the developing solution is shaken off, and the developing solution nozzle 4 is replaced with the developing solution nozzle 4 and positioned at the center.

■Next, stop the flow of rinsing liquid and rotate at high speed to dry.

At this time, for example, if the rotation speed when the rinsing liquid is flowing down is several hundred rpm, the rotation speed during drying is increased to about 3000 rpm.

As is well known, there are two types of resists to be applied to the substrate to be processed: positive resists and negative resists.Positive resists are resists in which exposed areas are removed for development, and negative resists are resists in which exposed areas are removed for development. This is a type of resist in which the unexposed areas are removed by development. Further, while negative resists usually use organic solvents as a developer and a rinsing solution, positive resists use an alkaline aqueous solution as a developer and water (pure water) as a rinsing solution.

However, recently, as semiconductor devices have been miniaturized and the number of submicron-level patterns has increased, electron beam exposure methods suitable for miniaturization have been increasingly used, and resists for such electron beam exposure have a 4- A positive resist with good properties is often used.

[Problem to be solved by the invention]

As mentioned above, pure water is commonly used as a rinse solution for body resist, and even though it is possible to wash away the developer and stop development in the step (2), there is a problem in that it is difficult to remove dust. ing.

This is because the resist is an insulator and generates static electricity on its surface, which easily attracts dust.Furthermore, friction occurs between the pure water flowing down from the rinse liquid nozzle and the resist, and this friction generates static electricity. Therefore, dust is attracted and removed from the developed resist pattern for cleaning (cleaning).
It is considered difficult to do so. If this happens, pattern short circuits and the like are likely to occur, reducing the quality and yield of semiconductor devices.

The present invention solves these problems and proposes a method for developing a positive resist 5 for the purpose of forming a substrate surface to be processed having a clean resist pattern with less dust.

[Means to solve the problem]

This problem is solved by a positive resist development method in which the substrate to be processed after development is immersed in a rinsing solution containing a mixture of pure water and alcohol to stop and clean the development.

[For production]

That is, the present invention uses a rinsing liquid containing alcohol mixed with water instead of the conventional rinsing using only water (pure water). Then, since alcohol has an antistatic effect, it prevents electrification caused by friction between water and resist, prevents dust from adhering, and also removes dust that has already been adsorbed due to electrification, leaving a clean resist. A pattern can be formed.

〔Example〕

Hereinafter, a detailed description will be given with reference to an example. For example, a substrate to be processed coated with TSMR-V3 (manufactured by Tokyo Ohka; trade name) as a body resist is selectively exposed using a reduction exposure device (stepper), and then the first Set it in the developing processing apparatus shown in the figure, and statically develop it for 1 minute with an alkaline aqueous solution (developer). Next, while rotating the substrate to be processed at 800 rpm, a mixed solution of pure water and isopropyl alcohol (rinsing solution) is flowed down from the rinsing solution nozzle for 30 seconds, and then the rotation speed is increased to 3000 rpm for spin drying. At this time, pure water mixed with 10% isobrobyl alcohol is used as the rinsing liquid.

After carrying out the process in this manner, the substrate to be processed was left for one hour, and as a result of observing dust with a size of 0.3 μm or more using a wafer surface inspection device, it was possible to reduce the number of dust by about 30%. Therefore, according to the development processing method of the present invention, it is possible to remove dust on a pattern, and it is difficult for dust to adhere even after that, and a fine pattern can be formed with high precision.
This can be useful for improving the yield and quality of semiconductor devices.

In this example, the rinsing liquid was pure water mixed with 10% isobrobyl alcohol, and the amount of the mixture was 40%.
% or less, because if the alcohol amount increases, the resist may be slightly dissolved, and the appropriate amount is considered to be about 10 to 20%.

Further, the alcohol is not limited to the isopropyl alcohol used in the examples, but ethyl alcohol or methyl alcohol may also be used.

〔Effect of the invention〕

As explained above, the development process according to the present invention can reduce dust in resist patterns, form fine patterns with high precision, and has a great effect on improving the yield and quality of semiconductor devices. It is.

It goes without saying that the present invention can be applied not only to semiconductor wafers but also to pattern formation of electronic components such as printers 1 and substrates.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the main parts of the developing device. In the figure, 1 is a substrate to be processed, 2 is a rotation stage, 3 is a cover, 4 is a developer nozzle, and 5 is a rinse liquid nozzle. 9th

Claims (1)

[Claims] In a development processing method in which a substrate coated with a positive resist is selectively exposed, developed and rinsed, the substrate after development is rinsed with a mixture of pure water and alcohol. A method for developing a positive resist, characterized in that development is stopped and washed using a solution.