JPH0246769A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve the adhesion between an Si thin film and an Si substrate by forming a silicide layer of IVA or VA metal, a metal oxide film, and a single crystal Si thin film, on an Si substrate. CONSTITUTION:A thermal oxide film 4 is formed on a substrate 3 of an Si substrate I; Ti (IVA or VA metal 2 such as Zr, Hf, Ta, Nb and V) is formed on a substrate 1 of an Si substrate II; the surface of Ti2 and the surface of SiO24 are brought into contact with each other, and heat-treated. When long time heat treatment is performed at a temperature of, e.g., 1000 deg.C, Ti2 reacts with the Si substrate 1, and forms TiSi25. At the same time, SiO24 and Ti2 react with each other, and form TiO26. The following interfaces are obtained by chemical reaction based on heat, and the adhesion is very excellent; interface between the Si substrate 1 and a Ti silicide layer 5, interface between the TiSi2 layer 5 and a TiO2 layer 6, and interface between the TiO2 layer 6 and the Si substare 3. By polishing the Si substrate 3, a single crystal Si thin film 3' of 0.1-10mum thick is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor device and a manufacturing method. This is particularly effective in improving the reliability of high-speed LSIs.

[Conventional technology]

Conventionally, in semiconductor devices with SOI structure, Si substrate! Alternatively, the surfaces of the Si substrate I′ on which the thermal oxide film was formed and the 31 substrate If on which the thermal oxide film was formed are brought into contact, and after bonding by heat treatment, the Si substrate TI is polished from the back side.
A 5iO=film is formed on the Si substrate by a manufacturing method for forming a single crystal Si thin film of 0.1 to 1Oμm, and the S1
0. A semiconductor device having an SOI structure on which a thin film of Si is formed was used.

[Problems to be Solved by the Invention] However, in conventional semiconductor devices, the adhesion strength of the adhesive interface St/5iOz interface or 51o2/5io2 interface between two Si substrates is poor, and during the process of forming a device on the Si thin film. The present invention avoids such conventional drawbacks and provides a highly reliable semiconductor device with excellent adhesion between the Si thin film and the Si substrate, and a manufacturing method thereof. The purpose is to

[Means for Solving the Problems] In the cross-sectional structure of the semiconductor device of the present invention, I
A VA or VA gold metal silicide layer, the metal oxide film, and a single-crystal Si thin film are formed.6 According to the present invention, the metal silicide and the Si substrate have a bond between the metal and Si. Strong and has excellent adhesion. In addition, the interface between the silicide and the metal oxide film and the interface between the metal oxide film and Si also have strong chemical bonds and excellent adhesion, so the Si thin film forming the upper layer device does not peel off from the Si substrate. A highly reliable semiconductor device can be obtained.

[Example 1] This will be explained below using an example. 1 to 3 show cross-sectional views of a semiconductor device according to the present invention and its manufacturing process. In FIG. 1, a thermal oxide film 4 is formed on a substrate 3 of a Si substrate I,
On the other hand, on the substrate l of the Si substrate II, Ti (Zr, H
In FIG. 2, an IVA or VA metal 2) such as Ta, Nb, or V is formed, and the surfaces of the Ti2 and the SiOz 4 are brought into contact with each other and heat treated. When heat treatment is performed, the Ti2 becomes the S
At the same time as it reacts with the i substrate l to form Ti5iz 5.

This is because when S i O24 and Ti2 react to form Ti026, the reduction of S i O2 proceeds because it is more stable to form IVA, VA gold metal, or oxide.

The interface between the Si substrate 1 and the Ti silicide layer 5, the interface between the Ti51w layer 5 and the TiO□ layer 6, and the interface between the TiO□ layer 6 and the Si substrate 3 are all interfaces obtained by chemical reactions caused by heat. , adhesion is very good. In Figure 3,
By polishing the Si substrate 3, a single crystal Si thin film 3' is formed. By the above manufacturing method, as shown in Fig. 3,
On the Si substrate l, there are a T i S i two layer 5, a TiO2
A semiconductor device having an SO tank structure in which a layer 6 and a St thin film 3'' are formed is obtained.

[Effect 1 of the invention By forming a device on the Si thin film 3', Si
It becomes possible to provide a highly reliable semiconductor device with excellent adhesion between the thin film and the Si substrate.

1 myself

[Brief explanation of the drawing]

1.2.3 are cross-sectional views of a semiconductor device according to the present invention and its manufacturing process. Si substrate Ti Si substrate Ti0g T i S i 2 T i 02 Si thin film 72 items ￥ 3 yen

Claims (2)

[Claims] (1) An insulating film is formed on a Si substrate, a thin film of single crystal Si of 0.1 to 10 μm is formed on the insulating film, and a so-called SOI structure in which devices are created is formed on the thin film of Si. In the semiconductor device, an IVA or VA metal silicide layer is formed on the Si substrate, an IVA or VA metal oxide film is formed on the silicide, and a thickness of 0.1 to 10 μm is formed on the metal oxide film. 1. A semiconductor device comprising a thin film of single crystal Si. (2) On the surface of one of the two Si substrates, S
After forming an iO_2 insulating film and forming an IVA or VA metal layer on the surface of the other substrate II, the SiO
_2 The surface of the film is brought into contact with the metal surface, and the S
A method for manufacturing a semiconductor device, which comprises reducing iO_2 and then polishing the Si substrate I from the back side to form a single crystal Si thin film with a thickness of 0.1 to 10 μm.