JPS60164336A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent generation of stress by a method wherein the first semiconductor layer is grown on a semiconductor substrate, a plurality of plane surfaces having different heights are formed oxidating and etching a part of said semiconductor layer, the second semiconductor layer is grown, and a part of the semiconductor surface is electrically isolated by oxidation. CONSTITUTION:An N<+> type buried layer and a P<+> channel stopper 103 are diffused on a P type semiconductor substrae 101, and an N type epitaxial layer 104 having the thickness approximately ond half of the epitaxial layer is grown. Then, a thin oxide film 105 and a nitride film 106 are grown, and a window is provided. Subsequently, a thick oxide film 107 is formed. Then, said thick oxide film, the thin oxide film 105 and the nitride film 106 are removed, and an epitaxial layer 104' is grown again until it will be formed to the desired thickness. A thin oxide film 105' and a nitride film 106' are grown again, and a thick oxide film 107' is formed. Besides an N<+> type diffusion layer 108 is formed, a P type base region 110 is diffused, and after an N<+> type emitter region 112 has been diffused, a metal wiring 113 is vapor-deposited. As a result, the stress accumulated on the region located in the vicinity of the interface of the oxide film and the semiconductor is reduced, thereby enabling to improve the withstand voltage of the semiconductor device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical summary to which the invention pertains] The present invention relates to an oxide film insulation isolation method or a partial oxide film insulation isolation method for semiconductor devices, and particularly relates to an oxide film insulation isolation method or a partial oxide film insulation isolation method for semiconductor devices, and in particular, to This invention relates to a method for using a semiconductor device in which a semiconductor chip is formed by growing an epitaxial part on this plane and partially oxidizing a part of the surface (3) of the epitaxial part.

[Prior art]

Conventionally, as the air supply reduction method #2 for bipolar type hand conductor devices, a buried layer is diffused on a flat semiconductor substrate and the subsequent process 1-'
An oxide film insulation isolation method or a partial nitride film insulation isolation method has been used in which a taxial layer is formed and a portion 5 of the epitaxial portion is selectively oxidized.

Figure 1 shows the conventional method of growing a thick oxide film twice (
An oxide film created by the method (hereinafter referred to as the double-purification method)? This is a cross-sectional view to clarify the type of process used to form a bipolar transistor using the edge separation method.

In the first section (a), an N+ type folding layer 2 is formed on a P type semiconductor substrate 1.
t Diffuse L, P+ trajectory channel stopper 3. And N-type epitaxial I? F4kMfk was used to form a thin permeable film 5 and a nitride film 6, and then
Using i11 technology, a window is opened as shown in the figure. after that,
A first thick 112 film 7 is formed on the ridge of Figure 1(b) by a pressure oxidation method or the like. And Figure 1 (C)
As shown in , the thick oxide film 7, the thin oxide film 5, and the voicing film 6 are etched, and if necessary, the thin oxide film 5 is etched again.
' and the nitride film 6' are reattached. Furthermore, a second thick oxide film 7' is formed by pressure oxidation (Fig. 1(d)).
. This embedding film becomes an insulating film for electrical isolation of a semiconductor device. Next, an N+ type diffusion region for reducing the electrical resistance of the collector shown in 1-ff1(e) is formed, a thermal oxide film 9 is grown, and the P type base head of 10 is diffused. .next.

As shown in FIG. 1(f), by forming an N type emitter diffusion region 12 and forming a metal electrode wiring 13, a bipolar base transistor is completed.

In the method shown in FIG. 1, when forming a thick oxide film with an electrical separation of 1%, the thick oxide film is grown twice.

Therefore, during the first oxidation shown in FIG. 1(b), the semiconductor expands when it changes into an oxide film, and stress accumulates in the region near the interface between the oxide film and the epitaxial layer. During the second acetylation as shown in FIG. 1(d), stress is further accumulated in the region near the interface between the oxide film and the epitaxial layer. The breakdown voltage of the base and collector (hereinafter referred to as BVcbo) of the transistor thus formed had the disadvantage of being low due to crystal defects generated by the addition of stress caused by these two oxidations.

[Purpose of the invention]

The purpose of the present invention is to provide a method for separating oxide films in semiconductor devices.
1 Hikari is a partial oxide film insulation division method, and in the dielectric isolation method using the double oxidation method, we have developed a method to reduce the stress accumulated in the region near the interface between the oxide film and the semiconductor, and to create semiconductor devices with high BVcbo. It is about providing.

[Structure of the invention]

In the method for manufacturing a semiconductor device of the present invention, a first
By growing a semiconductor layer and oxidizing or etching a portion of it, multiple planes with different heights are created on the semiconductor substrate.
growing a second semiconductor layer;

Thereafter, a part of the semiconductor surface is oxidized again to electrically isolate the semiconductor device.

[Explanation based on examples]

Next, a second method of supplying the semiconductor device of the present invention will be explained using an example.

FIG. 2 is a cross-sectional view for explaining an oxide film insulation isolation method using a double oxidation method for a semiconductor device according to the present invention. Figure 2 (a
), an N-type buried layer and a P-type channel stopper 103 are diffused into a PM semiconductor substrate 101, and finally an Nm epitaxial layer r@104 with a thickness of about half the thickness of the inevitable epitaxial layer is formed. grow. and,
A thin oxide film 105 and M nitride film 106 are grown, and a window is formed using a float etching technique. Thereafter, as shown in FIG. 2(b), oxidation using a pressure oxidation method, etc. 1. The i-th thick oxide film 107 is formed. Next, this thick oxide film and the thin oxide film 105 and nitride film 106 on the semiconductor surface are removed by etching to form the 21st MI (C). then %2nd
As shown in the figure, the epitaxial layer 104' is grown until it reaches the final desired thickness. 1. As shown in Fig. 2(e), a thin oxide a:tos' and nitride film 106' is grown again, and a second thick insulating film 107' is grown. , (see FIG. 2(f)).Furthermore, an N-type diffusion layer 108 for temporary resistor implantation of the collector shown in FIG. 2(g) is formed.
Diffuse the P type base plate shown in 10 and expand the N type emitter region 1 imaginary 112 as shown in Figure 2.Finally, metal wiring 113 for exposing the frost pole is evaporated. By using the manufacturing method of the present invention, a bipolar transistor can be manufactured (Section 2 [(h)).

In the transistor made in this way, the stress caused by the deep oxidation formed the i-th time;
C), but as shown in FIG. 2(d), the epitaxial layer tf
As the length of tQ increases, the effect of stress ψp disappears on the newly grown epitaxial layer (-7). During the second oxide film growth, only the stress at this time is applied, so crystal defects can be significantly suppressed without occurring at the interface between the oxide film and the epitaxial layer. As a result, the BVch□i@ pressure of the transistor can be significantly improved.

〔Effect of the invention〕

As explained above, by using the method for manufacturing a semiconductor device of the present invention, it is possible to significantly improve the breakdown voltage of a semiconductor device using an oxide film isolation method using a double oxidation method or a partial oxide film isolation method. .

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing a method of manufacturing a bipolar semiconductor device by an oxide film insulation isolation method using a conventional double oxidation method. FIG. 2 is a sectional view for explaining a method of manufacturing a bipolar semiconductor device by an oxide film insulation isolation method using a double oxidation method according to an embodiment of the present invention. 1.101...P-type semiconductor substrate, 2,102.
...N type buried layer, 3,103...P
Type channel stopper, 4,104,104'...
...N-type epitaxial layer, 5.5', 105,10
5'...Thin oxide film, 6. 6', 106.
106'...Nitride film. 7.7', 107, 107'...Thick oxide film,
8゜108...N type collector diffusion layer, 9,1
09°・. Oxide film, 10, 110...P type base region, 1
1゜111...Oxide film, 12,112・River...
N type emitter region, 13, 113...Metal wiring for exposing electrode area, (A)...First and second
The interface of the second epitaxial layer. Figure 2

Claims (1)

[Claims] The first conductivity type or the second conductivity type is formed on the semiconductor substrate shouldering the stripe 14 conductivity type.
By growing a first semiconductor layer of a conductive type and reducing the thickness of a portion of the first semiconductor layer, the cow! A plurality of planes having different heights are provided on the body substrate 11, a second semiconductor layer of a first conductivity type or a second conductivity type is provided on the first semiconductor layer, and the second semiconductor layer is provided with a first conductivity type or a second conductivity type. 1. A method for manufacturing a semiconductor device, characterized in that a rat ridge is provided in a part of the semiconductor device.