JPS62120017A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the generation of a facet which makes a semiconductor device cause a malfunction by forming a semiconductor layer on the sidewall of an insulating film of a hole by anisotropically etching, then epitaxially growing a semiconductor layer on a semiconductor substrate. CONSTITUTION:An Si substrate 1 is covered with an SiO2 film 2, then patterned, and a hole 4 is opened. A thin polycrystalline Si layer 5 is formed on the entire surface including the hole 4. Then, a polycrystalline Si layer 5 is anisotropically etched. Thus, the layer 5 remains only on the sidewall of the film 2. Then, the substrate 1 exposed on the bottom of the hole 4 is epitaxially grown to grown a single crystal epitaxial Si layer 6. Since the frictional resistance of the layer 6 and the layer 5 formed on the sidewall of the film 2 is relatively small, it can prevent a conventional facet from occurring.

Description

[Detailed Description of the Invention] [Summary] This method of manufacturing a semiconductor device includes forming a semiconductor layer on the sidewall of an insulating film in an opening by anisotropic etching, and then epitaxially growing the semiconductor layer on a semiconductor substrate. By doing so, it is possible to form a selective epitaxial layer without generating facets.

[Industrial application field]

The present invention relates to a method for manufacturing a semiconductor device, and more specifically, to a method for manufacturing a semiconductor device in which a semiconductor layer is formed on an exposed semiconductor substrate by opening an insulating film.

[Conventional technology]

E-FOX is a conventional method of element isolation using an insulating film.
There are 9 selective epitaxial growth methods. Among these methods, the E-FOX method has a problem in that a so-called bird's peak occurs and the area occupied by the element isolation insulating film becomes substantially large, making it impossible to achieve high integration of the elements. Although the insulating film embedding method does not have the drawbacks of the E-FOX method, it requires a planarization technique such as etching back the insulator formed in the trench, and is complicated.

On the other hand, the selective epitaxial growth method does not have the disadvantages of the E-FOX method, and is suitable for highly concentrating devices, and unlike the insulating film embedding method, there is no need to etch back the semiconductor layer after epitaxial growth. is easy.

[Problem that the invention seeks to solve]

FIG. 2 is a cross-sectional view illustrating the conventional selective epitaxial method, in which 1 is an SI large substrate 2 is a 5102 film.

3 is an epitaxial SAP formed by epitaxial growth on a Si substrate l.

By the way, as shown in FIG. 2, according to the conventional selective epitaxial method, facets may occur due to the frictional resistance between the 5102 film 2 and the epitaxial S1 layer 3 that occurs during growth. If this occurs, it may cause device defects such as poor breakdown voltage.

The present invention was created in view of the problems of the conventional method, and an object of the present invention is to provide a method for manufacturing a semiconductor device that forms a selective epitaxial growth layer in which facets do not occur.

[Means for solving problems]

The present invention includes a step of forming an insulating film on a semiconductor substrate, and then opening the insulating film to expose a part of the semiconductor substrate; and a step of forming a first semiconductor layer on the entire surface including the exposed portion.
etching the first semiconductor layer anisotropically to leave the second semiconductor layer only on the sidewall of the insulating film in the opening; and etching the second semiconductor layer on the semiconductor substrate whose bottom is exposed in the opening. and epitaxially growing a second semiconductor layer.

[Effect]

According to the structure of the present invention, before forming the second semiconductor layer by epitaxial growth, the first semiconductor layer is left on the sidewall of the insulating film by anisotropic etching. When the second semiconductor layer is epitaxially grown, there is relatively little frictional resistance between the semiconductor layer and the first semiconductor layer formed on the sidewall of the insulating film, so no facets are generated.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view illustrating a method of manufacturing a semiconductor device 1 according to an embodiment of the present invention.

(Step 1) First, a 5102 film 2 is deposited on an 81 substrate l, and then patterned to form an opening 4.

(Step 2) Next, a thin polycrystalline Si layer 5 is formed over the entire surface including the opening 4 by CVD technology.

(Step 3) Next, the polycrystalline 51 layer 5 is anisotropically etched.

As a result, the polycrystalline S1 layer 5 remains only on the sidewalls of the S, O2 film 2.

(Step 4) Next, a single crystal epitaxial growth 31 layer 6 is grown by epitaxially growing on the Si substrate l exposed at the bottom of the opening 4. Here, since the frictional resistance between the epitaxially grown S1 layer 6 and the polycrystalline Si layer 5 formed on the side wall of the 5102 film 2 is relatively small, the generation of facets as in the conventional example can be prevented.

Therefore, even when forming an element on the epitaxially grown layer 6, it is possible to prevent element deterioration and defects caused by facets.

〔Effect of the invention〕

As described above, according to the present invention, the simple structure of forming the second semiconductor film on the sidewall of the insulating film makes it possible to prevent the occurrence of facets that may cause device failure.

[Brief explanation of drawings]

FIG. 1 is a sectional view illustrating a method of manufacturing a semiconductor device n according to an embodiment of the present invention, and FIG. 2 is a sectional view illustrating a method of manufacturing a conventional semiconductor device. l...Si substrate (semiconductor substrate) 2...S, 0211! I2 4...Opening 5...Polycrystalline Si layer (first semiconductor layer) 6...Epitaxial growth SLR (second semiconductor layer) 'zr\, Agent Patent attorney Igeta, Sada. -゛i 2, 7 Sil Kei Slmu 1 O (15th Moon no U → (Otsuirorishin, E1 Figure 1

Claims (1)

[Claims] A step of forming an insulating film on a semiconductor substrate and then opening the insulating film to expose a part of the semiconductor substrate, and forming a first semiconductor layer on the entire surface including the exposed part. a step of anisotropically etching the first semiconductor layer so that the second semiconductor layer remains only on the sidewall of the insulating film in the opening; a bottom portion of the first semiconductor layer is exposed in the opening; A method for manufacturing a semiconductor device, comprising the step of epitaxially growing a second semiconductor layer on a semiconductor substrate.