JPS58145126A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To enable to form sharply a pattern having the desired shape, and to enable to integrate the device in a high grade by a method wherein the residue of a photo resist is removed according to an ultrasonic vibration, and the photo detecting part is made to come in contact directly with a developer at all times. CONSTITUTION:Water 14 is accommodated in an outside vessel 11, and the desired developer 15 is accommodated in an inside vessel 12. Ultrasonic waves are generated by an ultrasonic generator 13 in this condition, and when the waves thereof are transmitted to the outside vessel 11, the ultrasonic vibration is transmitted to the developer 15. When a semiconductor wafer 16 finished with the exposure treatment is set in the inside vessel 12 to be developed, even a fine opening part can be developed sharply.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a semiconductor device, and more particularly to an improvement in a method for forming a photoresist pattern in a desired shape using photolithography.

A lift-off method is known as a method for forming fine wiring layers in semiconductor devices. This lift-off method involves forming a pattern of mainly positive photoresist on the surface of a semiconductor substrate or wiring layer, depositing a metal film on top of the pattern, and then removing the photoresist. In this method, only the metal film No. 7 is removed together with the photoresist, and the metal film pattern other than on the photoresist is used as a wiring layer as it is. In this lift-off method 1, it is theoretically possible to form a metal film with an ultra-fine pattern such as a submicron pattern, but in that case, a photoresist pattern corresponding to the ultra-fine pattern must be sharply formed. That is the most important point. When forming this sharp photoresist pattern, selection of photoresist suitable for the desired shape and application conditions,
Although it is important to optimize baking conditions and exposure conditions,
Even after these have been optimized, what is even more important is finding the optimal development conditions. The development is
Theoretically, it is normal for the entire exposed area of the photoresist to be etched uniformly, but in reality, the etching speed may vary depending on the characteristics of the developer, differences in developer concentration, etc. There is. In addition, when the width 2 area of the desired opening (the part to be etched with the developer) of the photoresist film is small, such as the photoresist pattern used in the above-mentioned lift-off method, the development When the semiconductor substrate is immersed in the solution, the residue of the photoresist film etched with the developer remains on the surface of the semiconductor substrate, and only that part is blocked from contact with the etching solution, making it difficult to develop. If the amount is insufficient and an attempt is made to completely develop this portion, over-development will occur and only a pattern 1] wider than the desired shape of the photoresist pattern can be formed.

The present invention aims to improve the above-mentioned developing method, and an object of the present invention is to provide a method for manufacturing a semiconductor device characterized by applying ultrasonic vibration directly or indirectly to a developer. It is said that

The present invention will be explained below based on one embodiment.

This example is a case where the present invention is applied to a lift-off method.

In Figure 1, a positive photoresist (for example, AZ-1350 manufactured by Shipley, Inc., USA) film (2) is deposited on the surface of a semiconductor substrate (1) using a known method such as a spinner, followed by moderate baking treatment. (For example, 90℃ in the air, 2
0 minutes of baking treatment) is shown.

FIG. 2 shows a state in which ultraviolet rays are irradiated through a desired mask (3) as indicated by the dashed arrow in the figure (a-light treatment).

As a result, the photosensitive portion (2a) of the photoresist film (2) is photodecomposed.

FIG. 3 shows a state in which the photosensitive area (2a) has been etched and removed (development treatment) using a developer (for example, AZ developer manufactured by Shipley, Inc., USA), and then washed with water and dried.

FIG. 6 is an explanatory diagram of a developing device for carrying out the present invention, in which (11) is an outer container, (131 is an ultrasonic generator) an outer container, (131 is an ultrasonic generator) Water (141 is contained.

When an ultrasonic wave is generated by the ultrasonic generator (131) and transmitted to the outer container (11) while the inner container (one container contains the desired developer 05), the ultrasonic vibrations are generated. In this state, as shown in FIG. 2, the exposed semiconductor wafer (161) is placed in the inner container 02+ and developed. It was found that even the open areas were developed sharply.

Next, a metal film (for example, aluminum) is applied to the entire surface of the substrate shown in FIG. 3 using a known technique such as vapor deposition or sputtering. FIG. 4 shows a state in which the metal film (4) is applied including over the openings (2a) of the photoresist pattern.

Next, use a suitable photoresist solvent (e.g. acetone).
By melting the photoresist film (2) with do.

This completes the explanation of one embodiment of the present invention, and it can be seen that the present invention has the following effects.

That is, according to the conventional development method, when the opening [1] is narrow or the area is small, in other words, in the case of a fine pattern, the development is insufficient due to the etching residue of the photoresist by the developer. However, according to the present invention, ultrasonic vibration can Since photoresist residue is removed and the photosensitive area is always in direct contact with the developer, it is possible to form sharp patterns in the desired shape, making it possible to highly integrate semiconductor devices. In addition, uniform development can be performed even on large semiconductor substrates.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing a state in which a photoresist film is attached to a semiconductor substrate, Figure 2 is a cross-sectional view showing a state in which exposure processing is performed using a desired mask, and Figure 3 is a state in which development processing is completed. Figure 4 is a cross-sectional view showing the desired metal film adhered to the entire surface, Figure 5 is a cross-sectional view showing the desired metal film applied to the entire surface, and Figure 5 shows the desired metal film pattern obtained by dissolving the photoresist film using the desired solvent. FIG. 6 is a sectional view showing an example of the developing device used in the present invention. In the figure, (1) is a semiconductor substrate, and (2) is a photoresist film. (2a) is a photosensitive area, (2b) is a non-photosensitive area, and (3) is a mask. (4) is a metal membrane, ql) is an outer container, (121 is an inner container, +131 is an ultrasonic generator, tta is water, +1
5) indicates a developer, and +161 indicates a semiconductor wafer (semiconductor substrate). Agent Shin Shimano - Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] (1) A desired positive photoresist film is coated on the semiconductor substrate or the wiring layer formed thereon, and after the desired heat treatment, mask alignment, and exposure treatment are performed, a development treatment is performed to manufacture a semiconductor device. A method for manufacturing a semiconductor device, characterized in that the developing solution is subjected to ultrasonic vibration during the development process.