JPS58107635A - Preparation of semiconductor device - Google Patents

Abstract

PURPOSE:To easily confirm the completion of ething by opening a window only to a single crystal region but also to a supporting region in such a case of etching plurality of single crystal region separately formed on the isolated dielectric material substrate having the supporting region. CONSTITUTION:The Si single crystal island regions 113a, 113b are formed on isolated dielectric materiual substrate 110 where the insulating Si oxide films 112a, 112b are formed in a supporring region 111 consisting of the poly crystal Si, and for example vertical transistor and diode are formed on the island regions 113a, 113b. After the surface is covered with an oxide film, contact windows, for example, the collector contact window 114, emitter contact window 115, base contact window 116, cathode contact window 117, anode contact window 118 are finally provided thereon. At this time, a window 119 for checking the end of ethcing for oxide film is provided also on the polycrystal line supporting region 111. Thereby, the end of etching can be checked easily and overetching can also be provented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a semiconductor device, and particularly to a method of manufacturing an integrated circuit device using a dielectric isolation substrate.

When diffusing into a conventional dielectric isolation substrate, a method is adopted in which selective diffusion is performed into single crystal silicon using a silicon oxide film grown by thermal oxidation as a mask.

In the case of Jin, the completion of oxide film etching in the photolithography process was determined by the color of the opening on the single crystal silicon using a Gold J4 microscope. However, with this method, it is not possible to accurately observe the etching state, resulting in problems such as insufficient etching or excessive etching.

An object of the present invention is to provide a method for manufacturing a semiconductor device that solves these problems.

The present invention provides a semiconductor device comprising a photolithography f process on a dielectric isolation substrate comprising a support region that supports a plurality of single crystal regions on which circuit elements are formed while electrically insulating and separating them from each other. The method of manufacturing a semiconductor device is characterized by comprising the step of forming a window not only in the single crystal region but also in the support region.

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a plan view of a dielectric isolation substrate for explaining a conventional manufacturing method. This dielectric isolation substrate 10 has an insulating silicon oxide film 12 in a silicon polycrystalline support region 11.
1 and 12b through silicon single crystal island regions 13, respectively.
Even though the silicon single crystal island regions 1311 and 13b buried side by side with a% 13b are of the same conductivity type,
There may be 4 different conductivity types. A vertical transistor is diffused in the silicon single crystal island region 131.
The other silicon single crystal island region 13bK shows a state in which a diode is diffused and a contact window is opened. Collector contact window 1 for vertical transistors
4. Emitter contact window 1 s s Base contact window 16 area is provided, the diode is provided with cathode contact window 177 node contact window area. In the conventional method, the completion of oxide film etching was determined by observing with a metallurgical microscope whether or not an oxide film remained on these contact windows.

FIG. 2 is a plan view of a dielectric isolation substrate for explaining the manufacturing method of the present invention. In the figure, in this dielectric isolation substrate 110, silicon single crystal island regions 113a and 113b are provided in a silicon polycrystal support region 111 via insulating silicon oxide films 112J1 and 112b.

Vertical transistors are diffused in the silicon single crystal island region 11351, and the other silicon single crystal island region 113b
shows the state when the diode is diffused and the contact window is opened.

The vertical transistor has a collector contact window 114,
Emitter contact window 115, base contact window 11
The diode 117 is provided with a cathode contact window 117 and an anode contact window 118. At the same time, a window 119 for checking the completion of oxide film etching is provided on the polycrystalline support region 111. By providing this check window 119, confirmation of the completion of etching for forming contact windows in the collector and emitter space regions of the silicon single crystal island regions 113a and 113b can be very well controlled.

That is, a support region made of polycrystalline silicon and an element formation region made of single-crystal silicon were thermally oxidized under the same conditions, and a window was opened by photolithography, and ammonium heptatide and heptazate were respectively formed. When etching an oxide film with a mixed solution of Etching takes time, and the polycrystalline pattern can be clearly observed with a metallurgical microscope. When the pattern caused by the polycrystalline oxide film disappears, the oxide film on the single crystal silicon is completely removed, and there is substantially no excessive etching.

Therefore, according to the present invention, it is very easy to observe the end point of oxide film etching, so it is possible to manufacture a highly reliable semiconductor device with uniform characteristics.

The above embodiment describes the opening of the contact window.

However, it goes without saying that the present invention can be applied to all photolithography steps after thermal oxidation and before selective diffusion.

[Brief explanation of drawings]

FIG. 1 is a plan view partially showing a dielectric isolation substrate of a conventional semiconductor device, and FIG. 2 is a plan view partially showing a dielectric isolation substrate of a semiconductor device illustrating an embodiment of the present invention. . In the same figure, 10%110...dielectric isolation substrate, 1.1,1
1.1...Silicon polycrystalline support region, 12a,
12b1112a, 112b...---Silicon oxide film, 13a, 13b, 113Jl, 113b
...Silicon single crystal island region, 14,114...
...Collector contact window 515sl15...
...Emitter contact window, 16.116...
Base contact window, 17% 117... Cathode contact window, 18, 118... Anode contact window, 119... Window for checking completion of oxide film etching.

Claims (1)

[Claims] In a method of manufacturing a semiconductor device comprising a photolithography process on a dielectric isolation substrate comprising a support region that supports a plurality of single crystal regions on which circuit elements are formed while electrically insulating and separating them from each other, A method for manufacturing a semiconductor device, comprising the step of forming a window not only in the region but also in the support region.