JPH02213120A - Resist-pattern forming method - Google Patents

Abstract

PURPOSE:To improve development distribution within the surface of a wafer and to make it possible to form a resist pattern accurately by holding the wafer so that the surface of the resist film of the wafer is directed downward, immersing the resist film in developer in a container, thereafter supplying rinsing liquid into the container, and substituting the rinsing liquid for the developer. CONSTITUTION:A resist film 23 is applied on a wafer 24 and treated by exposure. When a pattern is formed on the resist film 23, said wafer 23 is held so that a surface 26 of the resist film 23 is directed downward. The result film is immersed into developer 29 in a container 27. Thereafter, rinsing liquid is supplied into said container 27, and the rinsing liquid is substituted for the developer 29. For example, the container 27 is lifted by the operation of a cylinder 30. The developer 29 is brought into contact with the entire surface of the resist film 23 of the wafer 29 at a time. During the development, a spindle 32 is driven with a motor 31 through a belt, and the wafer 24 is rotated slowly at about 10r.p.m. so that the difference in concentration does not occur during the treatment due to the agitation of the developer. Temperature regulating water is made to flow in the container 27, and the temperature of the developer 29 is regulated at the specified temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of forming a resist pattern on a wafer.

In order to improve the yield of ICs, it is important that the development be done evenly over the entire surface of the evaporator.

[Prior Art] FIGS. 9(A) and 9(B) show a conventional example. This is called a paddle development method, and FIG. 11A shows a state in which the phenomenon is occurring, and FIG. 2B shows a state in which development is stopped.

The resist film 2 that has been exposed to light is fixed on the chuck 3 with the exposed resist film 2 facing upward, and a developer is dripped from the nozzle 4 above the resist film 2. form. As a result, development is started.

After several tens of seconds have passed, the rinsing liquid for the development stopper is dripped from the nozzle 7, and as shown in FIG. is formed.

(Problem to be solved by the invention) To spread the developer and rinse solution quickly over the entire surface of the wafer.
Although the wafer 1 is rotated at a very low speed and the nozzle 4 is moved by 7ffi, there are inevitably spots where the liquid moves slowly.

For this reason, in the case of a developer, there is a time difference in the start of the development reaction at each location on the wafer.

In the case of rinsing liquid, add ffi? to the rinsing liquid. This delay causes a time difference in stopping the development reaction.

Due to this FtIWA difference, the development distribution varies within the wafer surface, making it impossible to form a highly accurate resist pattern.

An object of the present invention is to form a resist pattern with high precision by improving the development distribution within the wafer surface.

[Means to solve the problem]

As shown in FIG. 1, the present invention includes a step 10 in which a wafer is held with its resist film facing downward and the resist film is immersed in a developer solution in a container, and then a rinsing solution is poured into the container. This consists of a step 11 of supplying the developer and converting the developer into N with a rinse solution.

[For n]

In step 10 of the current immersion process, the resist film on the wafer comes into contact with the developer over the entire surface of the wafer at the same time, and development is started on the entire surface of the wafer at the same time without any time difference.

In the rinsing liquid a replacement step 11, the developer in the container is quickly replaced with the rinsing liquid, and development is stopped almost simultaneously over the entire surface of the wafer.

[Actual pus case]

FIG. 2 shows an embodiment of the resist pattern forming method of the present invention, and FIGS. 3 to 8 show the operation of the resist pattern forming apparatus used in the resist pattern forming method of the present invention. As shown in FIG. 3, the semiconductor resist pattern forming apparatus 220 includes a chuck mechanism 21 and a container mechanism 22. As shown in FIG.

Medium Immersion in developer liquid regarding step 10: Wafer 24 containing exposed positive resist film 23
is conveyed as shown by the arrow in FIG. 3 and placed on the chuck 25. The chuck 25 holds the wafer 24
is fixed by suction (Step S+ in Fig. 2). Below [8! are shown in Figure 2.

Next, the chuck machine W421 rotates 180 degrees around the axis X and reverses the chuck 4 (step S2). FIG. 4 shows the state at this time, in which the wafer 24 is placed on the surface 2 of the resist film 23.
Hold 6 horizontally (-) facing downward.

The container 27 is dish-shaped, and the four parts 28 on the top surface are shallow and have a size corresponding to the diameter of the container 4.

The developer 29 is stored here. The position of the developer 29 is 1
It is small at around 00cc.

The cylinder 30 is actuated and the container 27 is raised as shown in FIG. 5 (step 33).

As a result, the developer 29 is applied to the resist film 23 of the wafer 24.
contact all surfaces at the same time. When viewed from the wafer 24 side, resist G! The entire surface of 23 is immersed in the developer 29 at the same time.

As a result, the development of the resist film 23 starts simultaneously with τ being 0 on the entire surface.

Development is carried out for 30 to 60 seconds.

Further, the following operation is performed so that the developing image moves uniformly in a circle over the entire surface.

(2) The spindle 32 is belt-driven by the motor 31, and the shaft 24 is slowly rotated at approximately 1 Orpm+. This agitates the developer and prevents concentration differences from occurring during processing.

(2) Flow temperature-controlled water inside the container 27 as shown by arrow B to adjust the temperature of the developer 29 to a predetermined temperature.

■ Also, air is blown out as shown by the arrow 35 through the holes 34 around the cover 33, and the developer 29 is applied to the wafer 24.
Prevent it from going around the top surface.

This is because the developer that has entered the upper surface of the 1c 24 causes stains.

■ Regarding rinse liquid M exchange step 11: After 30 to 60 seconds have elapsed from the start of development, proceed to step (2) above.

While continuing the operations ① and ②, as shown in Fig. 6, operate the rinsing liquid into the container 27 as shown by the arrow C.
is supplied into the recess 28 from the center P of the bottom of the recess 28 (
Step 84).

By supplying the rinsing liquid, the developer overflows from the container 27 as shown by an arrow 39, the inside of the recess 28 is replaced by the rinsing liquid 40, and the rinsing liquid 4o comes into contact with the resist film 23 of the wafer 24, and the development is completed. Stop.

Here, the volume of the recess 28 is as small as about 100cc,
The -1 rinsing liquid 40 is supplied at a flow rate of several hundred cc per second, and since the supply is performed from the center P of the bottom surface of the recess 28, the replacement of the developer with the rinsing liquid is instantaneous.

As a result, the entire surface of the resist film 23 of the wafer 24 comes into contact with the rinsing liquid 40 substantially simultaneously, and development is stopped substantially simultaneously over the entire surface of the wafer, forming a resist pattern.

As mentioned above, development is started and stopped at almost the same time on the entire wafer surface, so development is uniformly performed over the entire wafer surface, and the degree of variation in development within the wafer surface (for example, the same When developing a line of the same width, the degree of variation in the line width dimension at each position is approximately 1/2 that of the conventional method shown in Fig. 9, and a resist pattern with good precision is formed. , the yield of IC is improved.

After the development is stopped, as shown in FIG. 7, the container 27 is lowered and the rinse liquid 40 is drained through the valve 36.

Subsequently, the wafer 34 is heated approximately 3. The wafer 24 is dried by rotating at a high speed of OOO rpm.

After this, as shown in FIG.
The wafer 24 is rotated 0 degrees and returned to the transport position Q.

Thereafter, the dryer 41 that blows out air is moved in the direction of arrow 07-1 so as to scan the top surface of the container 27, and
Dry. Although droplets of the rinsing liquid scatter during this drying, since the wafer 24 is located at the transfer position, the droplets do not adhere to the wafer 24.

(Effects of the Invention) As explained above, according to the present invention, development is started simultaneously over the entire wafer surface and stopped almost simultaneously over the entire wafer surface. It is possible to suppress the variation in color to a smaller value than in the past, to achieve uniform development, to form a resist pattern with good viscosity, and to improve the yield of ICs.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the principle of the resist pattern forming method of the present invention, FIG. 2 is a diagram showing an embodiment of the resist pattern forming method of the present invention, and FIG. 3 is a diagram showing an example of the resist pattern forming method of the present invention. Figure 4 shows the state of the device during the wafer adsorption process, Figure 4 shows the state when the wafer is turned over, Figure 5 shows the state when the container is on its back (at the start of development), Figure 6 shows the condition of the rinsing liquid. Figure 7 shows the state after the current FIi is stopped; Figure 8 shows the state in which the wafer is returned to the transport position; Figure 9 shows the conventional example. It is a diagram. In the figure, 20 is a resist pattern forming device, 21+ is a chuck mechanism, 22 is a container mechanism, 23 is an exposed positive resist resistor, 24 is a wafer, 25 is a chuck, 27 is a container, 28 is a shallow four part, 29 is a developer 30 is a cylinder, 31 is a motor, 33 is a cover 35 is an arrow indicating air blowout, 36 is a valve, 37 is a drainage receiver, 39 is an arrow indicating overflow, 40 is a rinsing liquid, and 41 is a dryer.

Claims (1)

[Claims] A method for patterning a resist film (23) coated on a wafer (24) and exposed to light, comprising: holding the wafer with the resist film facing downward;
A step (10) of immersing the resist film in a developer (29) in a container (27), and then a step (11) of supplying a rinsing solution (40) into the container to replace the developer with the rinsing solution. ) A method for forming a resist pattern.