JPS58102538A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To allow the formation of an element isolation structure in a simple process, by constituting the isolation structure of an oxide film and a p type Si region left at the bottom of a V-groove. CONSTITUTION:Over the entire surface of a p type Si semiconductor substrate 1, an n type impurity is injected at high density resulting in the formation of an n<+>b region 2. Using dichlorosilane as reaction gas, a p type epitaxial layer 4 is grown over the entire surface on the substrate. This epitaxial growth using dichlorosilane has a large growing speed on a V-groove, and accordingly the surface of the epitaxial layer 4 turns into a gentle surface even on the V-groove. Over the entire surface, an Si3N4 film 5, as an oxidation resisting film, is formed and removed on the V-groove, and then the epitaxial layer 4 on the V-groove is oxidized in oxidizing atmosphere. Even when the epitaxial layer 4 is oxidized from the surface down to the n<+>b region 2, a p type Si region 4' is left at the bottom. After removing the Si3N4 film 5, various kind of elements are formed on the region surrounded by an oxide film 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present IR relates to a method for manufacturing a semiconductor device, and in particular to a method for forming an isolation oxide film using iso-pxanar technology.

--The first half of * separation technology includes isobrener technology that uses oxide films. This technique selectively oxidizes an epitaxial layer formed on a substrate, and isolates elements by surrounding the epitaxial layer with a thick oxide film. The problem with this isoplanar technology is that an n-type inversion layer is formed under a thick oxide film, making it impossible to achieve sufficient device isolation. Rounding Up Conventionally, there have been proposals to form a P-type region for channel cutting under a thick oxide film, but both require complicated processes and are not practical. The purpose of the manufacturing method of the present invention is to provide a manufacturing method that can easily form an oxide film element isolation structure. Form a groove (1, l
, l) Step of exposing the surface metal, dichlorosilane (B
A step of forming an epitaxial layer of one conductivity type on the surface of the skeleton substrate by epitaxial growth using IH*Ok gas, oxidizing the epitaxial layer on the VM groove by selective oxidation, and forming the tip of the VM groove. It is defined as 1% mold to have the steps of forming an oxide film by removing the oxide film, and forming various elements in the region surrounded by the oxide film.

An embodiment of the present invention will be described in detail below with reference to the drawings.

In the present invention, when epitaxial growth is performed using dichlorosilane gas (sin, at,), the crystal plane is (1,0,
This actively utilizes the property that growth is slow on 0) and fast on (1, 1, 1).

Refer to Figure 1, Nl1l is applied to the entire surface of the silicon conductor substrate 1! Impurities (for example, As, Nb, etc.) are implanted at a high concentration to form a region 2tl-. Then, the substrate surface is selectively etched by well-known anisotropic etching (1°1.1).
Etch the vII groove 3t until the surface is exposed.
- form. Core 7) V! Ml@3 has sufficient depth to separate n+ regions 2. Incidentally, phosphorus (1')f is implanted into a part of the n+ region 2 to form a region 2'.

Second! Using d,, B, H,, 81H, Ot, (dichlorosilane) as the gl reference reaction gas, Pa11! was applied to the entire surface of the substrate. Grow epitaxial layers. Epitaxial growth using this dichlor/ran can be performed, for example, with heptanosilane (8i
Compared to growth using H,) or silicon tetrachloride (si(3t4)'), the growth rate is slower on the (1,0,0) plane and faster on the (1,-1,1) plane. Because of this, the growth rate is high on the VG groove 3, and the surface of the epitaxial layer is
Even on vm groove 3 it is gentle.

It becomes a surface.

@See Figure 3 An 811N4 film 5 is formed as an oxidation-resistant film on the entire surface, and V
Remove the top of the mold groove. Then, the epitaxial layer 4 on the VTI trench is oxidized in an oxidizing atmosphere. ■Since the thickness of the epitaxial layer on the end (piece part) of the mold groove 3 is smaller than that on the bottom of the vm groove 3, the epitaxial layer 4 is oxidized from the surface to reach the n+b region 2. Also, a Fip type silicon region 4' remains at the bottom.

Referring to FIG. 4 81, after removing the N4 film 5, various elements are formed in the region surrounded by the oxide film 6. In this embodiment, an ivy region 8T and a collector region 8T are formed in the NFI process, and the P-type epitaxial layer 4 is used as a space region.
1t-provided.

According to this embodiment, the isolation structure is composed of the oxide film 6 and the pg silicon region l left at the bottom of the v3. In the manufacturing process, the epitaxial layer grown on the V-shaped groove 3 is grown using dichlor/ra/gas, and its selectivity makes it V-shaped! Since the four-layer pitaxial layer 4 is formed substantially flat on the surface of the layer 3, the conventional process of scraping the surface, for example, is not necessary.

As explained above, according to the present invention, an element isolation structure can be formed in an extremely simple process.

[Brief explanation of the drawing]

1 to 4 are cross-sectional views of the manufacturing process of one embodiment of the present invention.

Claims (1)

[Claims] A step of exposing a surface of a semiconductor substrate of one conductivity type having a (1,0,0) plane KVtlNllfr type 11te(1,1,1)Iit, dichlorosilane (81H,ot*) a step of forming a conductive epitaxial layer on the surface of the substrate by epitaxial growth using a gas; a step of oxidizing the epitaxial layer on the VTM groove by selective oxidation to form an oxide film except for the tip of the VTM groove; A method for manufacturing a semiconductor device comprising the step of forming various elements in a region surrounded by an oxide film.