Semiconductor device and preparation method thereof

Abstract

The invention provides a semiconductor device and a preparation method thereof. According to the invention, the SiC pre-buffer layer is used as a buffer structure between the Si substrate and the epitaxial layer, so that the growth quality of the epitaxial film can be ensured. In addition, the traditional processes of pre-paving an aluminum layer and growing a low-temperature aluminum nitride buffer layer are omitted, so that the buffer layer process of the semiconductor device can be simplified, and the risk of parasitic reaction in the process can be reduced. In addition, the problem of electric leakage caused by electric conduction of the Si substrate due to diffusion of Al in the traditional pre-paved aluminum layer to the Si substrate is avoided, so that the risk of electric leakage of the semiconductor device can be reduced.

Description

technical field [0001] The present application relates to the technical field of semiconductors, and in particular, to a semiconductor device and a preparation method thereof. Background technique [0002] The third-generation wide-bandgap direct-bandgap semiconductor material represented by GaN is a new type of semiconductor material that has received international attention in recent years. It has excellent physical and chemical stability, high saturation electron drift velocity, high breakdown field strength and Superior properties such as high thermal conductivity make it the most preferred material for the preparation of short-wavelength semiconductor optoelectronic devices and high-frequency, high-voltage, and high-temperature microelectronic devices. [0003] Traditionally, the substrate for growing GaN thin films in this field is mostly sapphire (Al 2 O 3 ), lithium aluminate (LiAlO 2 ), silicon carbide (SiC), gallium arsenide (GaAs), etc. Among them, the epitaxi...

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Problems solved by technology

However, due to the serious lattice mismatch between Si and GaN (lattice mismatch rate of 17%), thermal mismatch and reflow etching, etc., it is easy to cause cracks and uneven surface morphology of GaN epitaxial film and other phenomena

[0005] In view of this, it is usually necessary to pre-lay an aluminum layer on a Si substrate, grow a low-temperature aluminum nitride (AlN) buffer layer, a high-temperature aluminum nitride (AlN) buffer layer, and then grow a GaN film, resulting in the current Si substrate and The buffer layer process between GaN thin films is cumbersome and time-consuming, and parasitic reactions are prone to occur during the process, and there is a high risk of leakage

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