JPS61226750A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent occurrence of dust due to contact and to enhance yield by removing a resist around a wafer at the time of exposing the resist through a mask set above the wafer after coating the resist. CONSTITUTION:The semiconductor substrate wafer 11 is coated with the UV sensitive positive type resist 12 and the resist 12 is prebaked under prescribed conditions. The photomask 13 is set above the wafer 11 by using a projection reflective type exposure device, and the resist 12 is exposed. The mask 13 is formed so as to transmit UV rays and to cast them on the border of the wafer 11 at the time of exposure. The part of the resist 12 exposed to the UV rays is selectively and perfectly removed by immersing the wafer 11 in an alkaline developing soln. in a developing step, and washing it with pure water and drying it, thus permitting stable yield to be attained by eliminating the cause of yield deterioration that the resist 12 is peeled and dust occurs.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a method for manufacturing a semiconductor device, and in particular, in a photolithography process, only the peripheral portion of a resist coated on a semiconductor substrate (wafer) is selected. The present invention relates to a method for removing dust and reducing dust.

[Technical background of the invention and its problems]

Generally, the resist on the periphery of the semiconductor substrate hits the transport mechanism such as a transport carrier or etching device, becomes dust, and is reattached to the semiconductor substrate, causing a decrease in yield. A conventional example will be explained with reference to a resist coating apparatus shown in FIG. 3 and a coating process diagram shown in FIG. 4.

As shown in FIG. 3, the semiconductor substrate 1 is mounted on the vacuum chuck 2, and resist is applied from the nozzle 3. ◎7 is a resist flow rate adjustment valve.

Subsequently, the motor 5 rotates at a low speed to uniformly distribute the resist on the surface of the semiconductor substrate 10 within the surface of the semiconductor substrate. Next, while the motor 5 rotates at a low speed, a nozzle 6 is positioned so that the resist solution is spouted onto the periphery of the semiconductor substrate 1.
Resist solution sprays out. Finally, the motor 5 rotates at high speed, and the resist solution is blown away by centrifugal force, so that the resist is coated to a predetermined film thickness. 8 is a solvent flow rate adjustment valve, 9 is a semiconductor substrate 1
A cup surrounding the 0 rotation device, 10 is a drive control mechanism.
The coating process diagram in FIG. 2 shows the relationship between the number of rotations of the conductor substrate and the processing time, with resist coating at time TI, low speed rotation and resist melting around the semiconductor substrate at time T2, and time T.
.

represents high-speed rotation. In this way, the resist on the periphery of the semiconductor substrate 1 is removed.90However, in the above-mentioned conventional technology, the method of removing the resist on the periphery of the semiconductor substrate 1 in the coating process had the following problems. . The first problem is that the vacuum chuck 2
In order to dissolve and remove the resist by spouting solvent from the nozzle 6 while rotating the semiconductor substrate 1 attached to the periphery of the semiconductor substrate 1, the solvent is spouted onto the periphery of the rotating semiconductor substrate 1.
After that, the solvent splashed into the cup 9 bounces back onto the resist portion of the semiconductor substrate 1 that is not dissolved and removed, thereby dissolving the resist and generating pinholes. @20 The problem is that when mounting the semiconductor substrate 1, it is not possible to mount the substrate 1 accurately in the center, so when dissolving and removing the resist around the periphery of the substrate 1, it is necessary to dissolve and remove the resist between the parts and between lots. The area is different. The problem with @3 is that the resist is removed using an organic solvent, so the used organic solvent needs to be collected and sent to a specialist industrial waste disposal company. Furthermore, there is a risk that organic solvent may enter from the q&1 portion of the vacuum chuck 2 and ignite from the motor or part of the electrical energy.

[Purpose of the invention]

Therefore, the present invention prevents the occurrence of pinholes due to solvent scattering, which are the problems of the conventional technology, and prevents variations in the area of resist removal, and removes the resist with high precision. The purpose is to prevent dust from coming into contact with carriers, etching equipment, etc., and to improve yield. The present invention also aims to solve the problem of industrial waste disposal and safety such as fire by not using organic solvents.

[Summary of the invention]

In the present invention, when performing mask alignment on a semiconductor substrate, a photomask is used in which the transparent part or non-transparent part of the photomask corresponds to the part of the resist on the periphery of the semiconductor substrate that is to be removed. It is characterized in that the photosensitive properties of the semiconductor substrate are utilized to dissolve and remove the smear on the periphery of the semiconductor substrate in the development process.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
The coating process diagram in FIG.

Next, as shown in FIG. 1(b), after the mask of the sea urchin 11 is aligned using a reflection projection type exposure apparatus, exposure is performed to expose the resist 12. That is, the photomask 13 used in this mask alignment and exposure process is sl! As shown in FIG. 2, the photomask is shaped to transmit ultraviolet rays so that when the mask is aligned with the semiconductor substrate 11, the periphery of the semiconductor substrate 110 is exposed to ultraviolet rays. In FIG. 2, 14 is a portion that may or may not allow light to pass through depending on the type of resist, 15 is an /f turn region, and 16 is a matching dot. Next, the resist at the periphery of the semiconductor substrate 11 exposed to ultraviolet rays is immersed in an alkaline developer in the next development process, washed with pure water, and dried, resulting in the resist being exposed to ultraviolet rays as shown in Figure Wc1 (C). This completes the selective removal of the resist around the semiconductor substrate 10.

Note that the present invention is not limited to the above-mentioned embodiments, and can be applied in various ways. For example, if the eighting portion 14f in FIG. 2 is made of a non-transmissive type, it can be used as a photomask for removing a negative resist, and the resist from the peripheral portion of the semiconductor substrate can be removed.

〔Effect of the invention〕

As explained above, according to the present invention, problems such as pinholes caused by solvent scattering on the resist coated on a semiconductor substrate and a decrease in yield due to variations in the area of the resist to be dissolved and removed, as in the prior art, can be avoided. ◎In the present invention, the mask alignment process and the development process are combined,
Since the resist is removed from the periphery of the semiconductor substrate, the area t of resist dissolution and removal can be controlled with high accuracy, and since no solvent is used, problems of fire and pollution can be solved at the same time. In addition, the main purpose of the present invention is to solve the problem of resist peeling off and generation of dust due to contact between the resist around the semiconductor substrate and the carrier or etching equipment, which causes a decrease in yield, thereby achieving stable yield. This is something that can be obtained.

[Brief explanation of the drawing]

Figure 1 is a process explanatory diagram of an embodiment of the present invention, Figure 2 is a schematic configuration diagram of a photomask used in the same embodiment, Figure 3 is a diagram of a conventional resist removal apparatus, and Figure 4 is the same apparatus. 0 11...semiconductor substrate, 12...resist, 13...
・Photomask. Applicant's Representative Patent Attorney Takehiko Suzue Figure 1 Figure I Mt2

Claims (1)

[Claims] 1. A method for manufacturing a semiconductor device, which comprises applying a resist to a wafer in a photolithography process for semiconductor devices, and then removing the resist around the wafer by exposing the resist to light through mask alignment.