JPS5831554A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To provide an insulating and isolating method adapted to manufacture a semiconductor device having low power consumption, high density and high speed by flatly coating a silica film on recesses etched on a semiconductor substrate by a method which has the steps of immersing the substrate in a solution of silicon organic compound and applying an ultrasonic wave externally thereto. CONSTITUTION:An epitaxial layer is etched by a sputter etching method to form recesses 15, a photosensitive resin film 14 is removed, a dioxidized silicon film 16 is thinly formed, a substrate is then immersed in a solution of silicon organic compound dissolved in an organic solvent while applying externally an ultrasonic vibration, the solvent is volatilized in a horizontal drying tray, and a silica film 17 is thereafter coated on the overall surface of the substrate. Subsequently, the substrate is heat treated in a high temperature oxygen atmosphere to convert the film into a dioxidized silicon film. Then, the dioxidized silicon film is etched to expose the raised surface of the semiconductor substrate, and a base 18, an emitter 19 and metal wires 20 are formed by an ordinary method, thereby forming a bipolar semiconductor device. Thus, no defect is produced due to the stress distortion in the region formed with an element.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming insulation separation between each element constituting a semiconductor device, and the present invention relates to a method for forming insulation separation between each element constituting a semiconductor device. The present invention also provides an insulation isolation formation method suitable for manufacturing high-speed semiconductor devices.

Conventionally, PN junction isolation has generally been used to isolate each element of a bipolar semiconductor device.

However, in PN junction isolation, junction leakage current, junction capacitance, and lateral inward spread of diffused impurities when forming a deep isolation layer impede lower power consumption, higher speed, and higher density. Ta.

Therefore, insulation isolation has come to be used instead of PN junction isolation. A conventional insulation isolation method will be explained with reference to FIG. A recess 2 corresponding to an element isolation region is selectively formed in a semiconductor substrate 1 (FIG. 1a), and then the recess is filled with an insulating material, such as silicon dioxide (S 102 ). When filling the recess with Sio2, a method is usually used to thermally oxidize the substrate silicon, forming a layer 51023 as shown in Figure 1 (51023) and performing insulation isolation. However, with this method, the volume expansion due to thermal oxidation Therefore, large stress is applied to the separated regions, many defects occur, and device characteristics deteriorate.

Furthermore, since the element formation region becomes narrower by the thickness of the thermal oxide film, this method is not suitable for increasing the density of semiconductor devices when a thick thermal oxide film is required.

In order to eliminate the above-mentioned drawbacks of insulation isolation using a thermal oxide film, a method of filling the recesses with a silica film can be considered. However, when applying a silica film using the commonly used spin-on method, if the recesses are deep, the silica film may not reach the bottom of the recesses and air bubbles may accumulate. . Further, when the width of the recess is wide, it is difficult to fill the entire recess and obtain a flat silica film by one spin-on operation, and it is necessary to apply the silica film multiple times.

The present invention provides an insulating isolation forming method which eliminates the above-mentioned drawbacks of the conventional method and is suitable for manufacturing high-density, high-speed semiconductor devices with low consumption space and energy.

The present invention consists of the steps described below.

A photosensitive resin pattern is selectively formed on a semiconductor substrate, and the semiconductor substrate is etched by reactive sputter etching or ion milling to form recesses. After removing the photosensitive resin, the substrate is immersed in a solution of a silicon organic compound dissolved in an organic solvent while applying ultrasonic waves from the outside, and a silica film is applied to the entire surface of the substrate. Thereafter, heat treatment is performed in a high temperature oxygen atmosphere to convert the silica film into a silicon dioxide film. Next, after removing the silicon dioxide film formed on the convex portion of the semiconductor substrate, a semiconductor element is manufactured by a conventional method.

The present invention is characterized by a method of applying a silica film to the entire surface of the semiconductor substrate, covering the recesses selectively etched into the semiconductor substrate. In other words, if a semiconductor substrate is immersed in a silicon organic compound solution and a silica film is applied to the entire surface of the substrate by applying ultrasonic waves from the outside, it will fill all the recesses etched into the substrate and the silica film will be flat. It is applied.

Examples of the present invention will be described below with reference to FIG.

An impurity layer 12 of an opposite conductivity type is selectively formed on a Si semiconductor substrate 11 of one conductivity type. A Si semiconductor 13 having a conductivity type opposite to that of the semiconductor substrate is epitaxially grown on the entire surface. After selectively forming the photosensitive resin pattern 14, CF
The epitaxial layer is etched by sputter etching in a four-gas atmosphere to form a recess 16. Next, the photosensitive resin film 14 is removed, and a thin silicon dioxide film 16 is formed in a high temperature oxygen atmosphere to a thickness of, for example, 600 to 3000 Å.

After that, the substrate is immersed in a solution of a silicon organic compound dissolved in an organic solvent while applying ultrasonic vibration from the outside, and then the solvent is evaporated on a horizontal drying table, and a silica film is coated on the entire surface of the substrate. do. Thereafter, heat treatment is performed in a high-temperature oxygen atmosphere to convert the silica film into a silicon dioxide film. Next, the silicon dioxide film is etched to expose the surface of the convex portion of the semiconductor substrate, and a base 18, an emitter 19, and a metal wiring 2o are formed using a conventional method to form a bipolar semiconductor device.

In the method according to the present invention, the recesses formed in the semiconductor substrate are filled with a silicon dioxide film made of silica film, so unlike the conventional case where silicon dioxide is used by thermal oxidation, defects occur due to stress strain in the region where elements are formed. It is possible to manufacture high-performance semiconductor devices without any problems. In addition, since silica film is applied to a semiconductor substrate by impregnating it in a silicon organic compound solution while applying ultrasonic vibration from the outside, even if narrow and deep recesses are formed, it is possible to This prevents the situation where the recesses cannot be completely filled with silica film. Another advantage is that even if a large concave portion is formed in the larvae, the concave portion can be completely filled with silica film by a single application of impregnation.

[Brief explanation of the drawing]

FIG. 1 is a structural sectional view of a semiconductor device for explaining a conventional example, and FIG. 2 is a structural sectional view of a semiconductor device for explaining the present invention in detail. 11...St/semiconductor substrate, 12...
Opposite conductivity type impurity layer, 13...Epitaxial growth layer, 14...Photosensitive resin pattern, 16.
...Concavity, 162...Silicon dioxide film, 17.
・Fist: Silica film.

Claims (1)

[Claims] 1. A method for manufacturing a semiconductor device, comprising the steps of selectively etching a semiconductor substrate to form recesses, and applying a silica film to a sheet metal surface of a silicon-organic compound dissolved in an organic solvent.