JPS62216219A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To eliminate a problem of a step when deposited beta-SiC is flattened to be laminated in a multilayer by selectively forming an SiO2 film pattern on a silicon substrate, and depositing the beta-SiC only on the substrate. CONSTITUTION:A semiconductor device is composed of a single crystal silicon substrate 11, an SiO2 film 12, and an SiC film 13. After the film 12 formed on the substrate 11 is patterned, (3SiHCl3+C3H8+H2) gas is set by a reduced pressure CVD method to 400cm/sec of flowing velocity to react as (3SiHCl3+C3 H8+H2) (3SiC+9HCl+H2), thereby selectively growing SiC on the substrate 11. Single crystal beta-SiC is grown on a region limited by the film 12. Thus, the deposited SiC is flattened to eliminate a problem of a step when laminated in a multilayer to apply it to the manufacture of a superhigh speed hetero-junction bipolar transistor by utilizing the SiC as an emitter.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] β-3iC (3C-StC) is selectively grown on St using 5i02 as a mask.

[Industrial application field]

The present invention relates to a method for manufacturing a semiconductor device, more specifically,
The present invention relates to a method for selective growth of β-Si'C.

[Conventional technology]

SiC has a stable structure with a melting point of 2800°C and an energy band gap of 2 eV compared to 1.1 eV for Sl.
．． Since it is also 2eV, use SiC as an emitter,
Wide gap emitter bipolar transistor (ultra high speed heterojunction bipolar transistor, H~BT
) is attracting attention.

To grow SfC on a St substrate, there are methods such as atmospheric pressure chemical vapor deposition (CVD), sputtering, and sublimation.

[Problem that the invention seeks to solve]

Growth of SiC by atmospheric pressure CVD requires a high temperature of 1390° C., and cannot be used in the manufacturing process of semiconductor devices using St. In the case of sputtering, it was found that the crystallinity of the grown SiC film was not good.

In the sublimation method, a carbon source is turned into a vapor phase gas at high temperature and attached to a Si substrate, but there is a problem in that a SiC film with a large area cannot be formed.

In addition, in both methods, Si with good crystallinity is
There is a problem that the C film is not deposited and easily peels off.

The present invention has been made in view of the above points, and is based on the Sac
The object of the present invention is to provide a method for selectively depositing single crystals of.

[Means for solving problems]

FIG. 1 shows an embodiment of the present invention, in which 11 is a single crystal silicon substrate, 12 is a SiO+ film, and 13 is a SiC film.

In the present invention, SiO2 formed on a silicon substrate
After coating the 12 membranes, by low pressure CVD method,
3Si) Iri3 + C3Fly + H2 gas flow velocity (linevelocity) 400cm/s
3SiHCI by setting ec! 3 + C
, Hy+ H2→3SiC+ 9HCj! +H2 reaction to selectively grow SiC on the Si substrate.

[Effect]

In the above method, polycrystalline (po
lychrystalline)-like SiC grows, but because of its weak binding energy, HCI! Single-crystal SiC grows on the St substrate that is etched by Hα and is easily attached to SiC, and since it is deposited without being etched by Hα, single-crystal β-3iC grows in the area limited by the 5i02 film 12. do.

〔Example〕

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

Returning to FIG. 1 again, a film of 5i02 is formed on a single-crystal silicon substrate 11 (hereinafter simply referred to as a substrate) using a conventional technique.
Butter it to make 5iOz ff12.

Next, β-3iC (3C-Si) was
C) is selectively grown, but the reaction gas (3SiHCe
3 +C3Hr+ 82) at a flow rate of 400cm/s
ee, and 3SiH (J! 3 + C3Hy→
A reaction of 3SiC+ 98α+H2 is caused.

In the above reaction, SfC grows on the substrate, but 5I0
Polycrystalline SiC, which is not a single crystal, is grown on the two-layer film 12, which is marked with a circle in FIG. 1(a). The reason for this is that on the substrate, St and SiC are in a 1:1 stoichiometric state, and StC is easy to deposit there, but on the 5iO2 film 12, 5iOz and SiC are in a 1:1 ratio. Since there is no such state, single crystal SiC is difficult to grow, and polycrystalline SiC is deposited. Since such polycrystalline SiC has weak binding energy, HCJ? By continuing the above-mentioned reaction, SiO
Single crystal β-Si is selectively deposited on the two substrates 11 between the two films 12.
C is deposited.

Moreover, since SiC is deposited flatly only between the SiO2 film patterns 12, flattening is possible.
It is also possible to create a multilayer structure in which the structures shown in the figure are laminated.

An application example of the present invention is shown in FIG. 2, in which an n+ type buried layer which becomes a collector 12 is formed on a substrate 11, an n type epitaxial layer 15 is grown, and a p type epitaxial layer which becomes a base 16 is grown on it. and then grow 5i using the method described above.
02 film 12 is formed, and β-SiC film 13 is grown.

In order to make the β-SiC film 13 an emitter 23, it is made into n+ type by normal vapor phase doping or ion implantation, and a polysilicon film 17 for an electrode is formed thereon, thereby creating a HOT that operates at high speed.

Since StC is deposited flatly between 12 SiO2 films,
The structure shown in FIG. 2 can be stacked, and even in a multilayer structure, the problem of level differences does not occur.

The apparatus shown in Figure 3 was used to grow the β-30 film, in which 31 is a quartz double tube, 32 is an 8 KHz induction heating coil, 33 is a graphite susceptor, and 34 is a mass flow controller. (NFC), 35 is a vaporization controller. Using such an apparatus, (SiH(J! 3 +)
12 +C, H,) system gas was supplied to the inner tube of the double-structured tube 31, the susceptor 33 was heated to raise the temperature of the silicon substrate, and a β-SiC film was grown on the substrate.

〔Effect of the invention〕

As described above, according to the present invention, SiC is deposited flatly, so that no step problem occurs when stacked in multiple layers, and by using SiC as an emitter, ultra-high speed heterojunction bipolar transistors can be manufactured. It is applicable to

[Brief explanation of drawings]

Figures 1+a) and (1)) are cross-sectional views of embodiments of the present invention, Figure 2 is cross-sectional views of applied examples of the present invention, and Figure 3 is SiCIl! FIG. 2 is a cross-sectional view of the growth apparatus. 1 and 2, 11 is a silicon substrate, 12 is a SiO2 film, 13 is a SiC film, 14 is a collector, 15 is an n-type epitaxial layer, 16 is a base, 17 is a polysilicon film, and 23 is an emitter. . Example of the θ8 firing of this invention Figure 1 of the button flash Figure 2 of the difficult example of the invention of the nail ω flash Figure 2

Claims (1)

[Claims] A SiO_2 film pattern (12) is selectively formed on a single crystal silicon substrate (11), and 3SiHCl_3+C_3H_8→3SiC+9HCl is formed by low pressure chemical vapor deposition.
A reaction of +H_2 is generated, and β-SiC (13) is formed only on the substrate between the SiO_2 film patterns (12).
1. A method for manufacturing a semiconductor device, comprising depositing.