JPS5984550A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To remove an unnecessary metallic film remaining on a lift-off with excellent reproducibility by forming a coating pattern consisting of a photo- resist, etc. so as to coat a processed pattern section and removing the unnecessary section of a material as a desired pattern material while using the coating pattern as a mask. CONSTITUTION:One part of an insulating film 2 applied on a semiconductor substrate 1 is bored and processed while using a photo-resist film 3 as a mask, a metallic film 5 in Al, etc. is applied, the photo-resist is applied to flatten a recessed section, and a resist pattern 7 with size coating a desired metallic pattern 6 is processed and formed. The metalic film 5 is etched 8, 8' while using the pattern 7 as a mask to expose the upper surface of the photo-resist film 3. When the photo-resist remaining under the state is removed, unnecessary metal sections 9, 9' can be taken away simply. The quality of material of the coating pattern needs not be the photo-resist necessarily.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a method for manufacturing a semiconductor device using fine pattern processing.

[Prior art]

The lift-off method is mainly used to process fine patterns such as wiring metal in semiconductor devices.

Figure 1 is a structural cross-sectional view explaining the conventional lift-off method.
A photoresist film 3 is formed on a part of an insulating film 2 deposited on a semiconductor substrate (for example, a compound semiconductor substrate such as GaAs) 1.
This shows a state in which a hole 4 is made in the mask and a metal film 5 made of At or the like is deposited. Thereafter, when this sample is immersed in a solution that dissolves the photoresist and the photoresist is removed, the unnecessary metal film 5 on the photoresist is completely removed, and only the desired metal pattern 6 is formed. The conventional glue 7 to 7 method had the drawback that the photoresist was easily melted, leaving unnecessary metal and photoresist in some areas. In order to remove unnecessary metal, mechanical force such as ultrasonic vibration is used. If the desired metal pattern has weak adhesion to the semiconductor substrate, such as with FAu, peeling defects may occur. This made it difficult to process a good pattern.

[Purpose of the invention]

An object of the present invention is to provide a lift-off method with excellent reproducibility.

The metal layer deposited on the photoresist becomes a nuisance when dissolving the photoresist and is difficult to remove, especially if there is a large area and a thick metal layer on the photoresist. The present invention has been made to improve this drawback.

[Summary of the invention]

The gist of the present invention is as follows.

In the step of forming a pattern material on a sample, there is a step of uniformly applying the material to the entire surface, a step of applying a coating pattern made of photoresist or the like to cover the processed pattern portion, and a step of coating the entire pattern of the pattern material. The desired pattern material is formed by the step of removing unnecessary portions of the material that will become the desired pattern material as a mask, and the step of removing counterfeit materials from at least the first layer.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be explained with reference to FIG. In this embodiment, following the conventional process shown in FIG. 1, all the steps shown in FIG. 2 are added. After depositing a metal film 5 such as At, photoresist If is applied to flatten the entire recessed area, and the desired metal pattern is covered with a gold-rich resist/<turn 7 (coated material) turn). form (Fig. 2C(a)
)). The dimensions of this resist pattern are not limited, and may be just enough to cover the pattern gold in anticipation of the alignment accuracy of the photoring fin (usually ±0.5 .mu.m), or larger.

Subsequently, the metal film 5 is etched 8.8' using the entire resist pattern 7 as a mask to expose the entire upper surface of the photoresist film 3 (FIG. 2(b)). The remaining gold irises layer is marked 9°9'. If all the remaining photoresist is removed in this state, all unnecessary metal parts 9° and 9' can be easily removed (see Fig. 2 (C)).

The photoresist can be removed using a normal resist dissolving solution, but if contamination of the solution is to be avoided, plasma etching in a 02-gas atmosphere can also be used. did it.

In the above examples, a photoresist was used as the lower member of the metal film, but in the present invention, since the surface of the lower member can be exposed, 8 102 +, which has excellent heat resistance, is used as the lower member.
Using an insulating film such as SiN, the entire metal film can be removed by overetching. This has the characteristic that not only high-density metals such as Pt, Mo, and W, but also materials such as S11 phosphorus glass can be patterned by lift-off. Furthermore, the material of the covering pattern described in the above embodiments does not need to be photoresist.

Although the present invention has been described above as forming a metal pattern for a semiconductor device, it goes without saying that it can be applied to devices that require miniaturization such as Josephson junction devices.

〔Effect of the invention〕

According to the present invention, since most of the unnecessary metal film is removed in advance during lift-off, the photoresist film and the remaining unnecessary metal film can be removed with good reproducibility. As a result, the range of application of the 7-to-7 method has been expanded because there is no need for excessive mechanical vibration work, and even items with weak adhesion can be patterned using the lift-off method.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a process for manufacturing a semiconductor device according to a conventional method, and FIG. 2 is a cross-sectional view showing a process for manufacturing a semiconductor device according to the present invention. DESCRIPTION OF SYMBOLS 1... Semiconductor substrate, 2... Insulating film, 3... Photoresist film, 4... Opening, 5... Metal layer, 6... Metal pattern, 7... Resist pattern, 8 .8'...
- Etched portions 1.9, 9' of metal film 5...remaining metal portions. Army 1 Figure Z

Claims (1)

[Claims] 1. In the step of forming a pattern material on a predetermined substrate, a step of processing a pattern part on at least the first layer or above, and uniformly depositing the material that will become the desired pattern material on the above layers and the upper surface. a step of providing a covering pattern made of photoresist or the like to cover the above-mentioned processed pattern portion; and a step of using the entire covering pattern as a mask to remove unnecessary portions of the stripping material that will become the desired pattern material. A method for manufacturing a semiconductor device, characterized in that a desired pattern material is formed by the step of removing counterfeit money from at least the first layer.