JPS61188948A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To improve the reliability and integration by forming a polyimide film on a nitride silicon film formed on a semiconductor substrate, and then providing step of etching back both at substantially equal etching ratio, thereby flattening the surface of an interlayer insulating film. CONSTITUTION:The first layer electrode 4 connected with an impurity region 2 through a contacting hole and the first layer electrode 4 of the prescribed pattern are formed on an insulating film 3, and a plasma nitride silicon film 5 to coat the electrode 4 is formed on the film 3. Then, a polyimide film 6 to coat the film 5 is formed in the prescribed thickness. The film 6 is etched back by reactive ion etching until arriving at the surface region of the film 5 by substantially equal etching ratio. The recess of the film 5 is buried by the film 6 by flattening the surface to obtain a flat surface.

Description

[Detailed description of the invention] “　χ寥閤n)Chapter 49 Eight Evil〕 The present invention relates to a method for manufacturing a semiconductor device.

[Technical background of the invention]

Conventionally, a semiconductor device having a structure as shown in FIG. 3 has been manufactured as follows. First, an impurity region 21 is formed in a predetermined region of the semiconductor substrate 200, and then an insulating film 22 is formed to cover the surface of the semiconductor substrate 200 including this impurity region 21.
form.

Next, a contact hole communicating with the impurity region 21 is opened in a predetermined region of the insulating film 22. Next, the first layer electrode 23 is connected to the impurity region 21 through two contact holes.
A first layer electrode 23 having a predetermined pattern is formed on the insulating film 22. Next, a silicon nitride film 24 covering each first layer electrode 23 is formed on the insulating film 22. Next, a contact hole communicating with the first layer electrode 23 is opened in the silicon nitride film 24. Next, the second layer electrode 25 connected to the first layer electrode 23 through one contact hole and the second layer electrode 25 of a predetermined arm turn are connected to the silicon nitride film 24Vc.
Form.

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A John film 26 is formed on the silicon nitride film 24 to obtain a semiconductor device 30 that satisfies predetermined specifications.

[Problems with background technology]

This method of manufacturing a semiconductor device has the following drawbacks.

■ Silicon nitride M formed on the first layer electrode 23
Since the stepping force and distance of the second layer electrode 24 deteriorates, a concave portion called a mouse hole is formed in the second layer electrode 25, and breakage is likely to occur. This reduces the reliability of the device.

(2) Since the step coverage of the silicon nitride film is poor, the mutual spacing between the first layer electrodes 23 cannot be narrowed, and the mutual spacing between the second layer electrodes 25 becomes even wider. The degree of integration of the device cannot be increased.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a semiconductor device that can easily obtain a semiconductor device with improved reliability and degree of integration by flattening the surface of a glabellar insulating film.

[Summary of the invention]

The present invention includes a step of forming a silicon nitride film to serve as an insulating film between the eyebrows on a semiconductor substrate, then forming a 4-limide film on the silicon nitride film, and then etch-packing both at approximately the same etching ratio. Especially, this is a method of manufacturing a semiconductor device that can easily obtain a semiconductor device that has improved reliability and degree of integration by flattening the surface of the glabellar insulating film.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings. First, as shown in FIG. 1, an impurity region 2 is formed in a predetermined region of a semiconductor substrate 1, and then this impurity region 2'
An insulating film 3 is formed to cover the surface of the semiconductor substrate 1 including fc. Next, a contact hole communicating with the impurity region 2 is opened in the insulating film 3 by a well-known photolithography method. Then,
A first electrode connected to impurity region 2 through a contact hole.
The layer electrode 4 and the first layer electrode 4 of a predetermined pattern are covered with an insulating film 3.
Form on top. Next, a plasma silicon nitride film 5 covering these first layer electrodes 4 is formed on the insulating film 3.

Next, as shown in FIG. 2B, a polyimide film 6 covering the plasma silicon nitride film 5 is formed to a predetermined thickness.

Next, as shown in FIG. 6C, the polyimide film 6 is subjected to an etch pack process that reaches the surface area of the plasma silicon nitride film 5 by reactive ion etching with the etching ratio being approximately the same. Give well. By this surface flattening, the concave portions of the plasma silicon nitride film 5 are filled with the polyimide film 6 to obtain a flat surface.

Next, as shown in FIG. 1 (b), a contact hole communicating with the first layer electrode 4 is opened in a predetermined region of the plasma silicon nitride film 5. Next, a second layer electrode 7 connected to the first layer electrode 4 via a contact hole is formed on the plasma silicon nitride film 5.

After that, as shown in the same figure @), the second layer electrode 2 is covered.
A compression film 8 is formed on the exposed surfaces of the plasma silicon nitride film 5 and the polyimide film 6 to obtain a semiconductor device 10 that satisfies predetermined specifications.

As described above, according to this semiconductor device manufacturing method, by filling the recesses of the plasma silicon nitride film 5 with the polyimide film 6 and performing an etch pack process, it is possible to easily form a glabella insulating film with a flat surface. can do. the result,
The degree of integration can be improved by making the mutual interval between the first layer electrode 4 and the second layer electrode 7 sufficiently narrow. Also, the second
It is possible to prevent the layer electrode from breaking at 70 stages, thereby increasing the reliability of the device.

In the example, a semiconductor device having a two-layer glabella insulating film including a first layer electrode 4 and a second layer electrode 7 was obtained. However, as shown in FIG. In the same manner as above, a round insulating film between the eyebrows is formed on the second layer electrode 7 by filling the concave part with the 4-limide film 6 and flattening the surface by forming a plasma-thioated silicon film 5, and a contact hole is opened in this. A third layer electrode 11 connected to the second layer electrode 7 may be formed.

〔Effect of the invention〕

As described above, according to the method of manufacturing a semiconductor device according to the present invention, it is possible to easily obtain a semiconductor device in which the surface of the interlayer insulating film is planarized and the reliability and degree of integration are improved.

[Brief explanation of drawings]

1(A) to 1(G) are explanatory diagrams showing the method of the present invention in the order of steps, FIG. 2 is a sectional view showing another example of a semiconductor device manufactured by the method of the present invention, and FIG. 1 is a cross-sectional view showing the structure of a semiconductor device manufactured by a conventional method. DESCRIPTION OF SYMBOLS 1... Semiconductor substrate, 2... Impurity region, 3... Insulating film, 4... First layer electrode, 5... Plasma silicon nitride film, 6... Polyimide film, 7... ...Second layer electrode, 8...Passivation ILIO...Semiconductor device, 11...Third layer electrode. Applicant's representative Patent attorney Takehiko Suzue Figure 1

Claims (1)

[Claims] A step of forming a lower layer electrode in a predetermined pattern on a semiconductor substrate via an insulating film, a step of forming a silicon nitride film on the insulating film to cover the lower layer electrode, and a step of forming a polyimide film on the silicon nitride film. a step of performing an etch-back treatment on the polyimide film to reach the silicon nitride film so that the etching ratio of the polyimide film is approximately equal to that of the silicon nitride film to flatten the surface;
The method further comprises the steps of: opening a contact hole in the silicon nitride film leading to the lower electrode; and forming an upper electrode on the silicon nitride film to connect to the lower electrode through the contact hole. A method for manufacturing a featured semiconductor device.