A kind of semiconductor device and its preparation method

Abstract

The invention discloses a semiconductor device and a preparation method therefor. The semiconductor device comprises a substrate, a semiconductor layer positioned on the substrate, and a source electrode and a drain electrode positioned on the semiconductor layer, and a grid electrode positioned between the source electrode and the drain electrode, wherein the semiconductor layer comprises an active region and a passive region; at least one of the grid electrode, the source electrode and the drain electrode is divided into at least two sections, and one section is positioned in the active region while the other section is positioned in the passive region. According to the semiconductor device and the preparation method therefor, the passive region is formed in the semiconductor layer, and a part of conductive channels in the regions below the grid electrode, the source electrode and / or the drain electrode are destroyed, so that the heat generated by the channel is reduced, namely, the self heating of the semiconductor device is reduced, and the areas of the grid electrode, the source electrode and the drain electrode are not changed; and therefore, relatively speaking, the heat dissipation area of the device is enlarged, so that the heat can be effectively emitted.

Description

Technical field [0001] The present invention relates to the field of semiconductor technology, in particular to a semiconductor device and a preparation method thereof. Background technique [0002] The wide-bandgap compound semiconductor materials gallium nitride and silicon carbide have the characteristics of large forbidden band width, high electronic saturation drift speed, high breakdown field strength, and good thermal conductivity. They have shown extreme performance in high frequency, high temperature, high power and other fields. Great potential, especially GaN high-electron mobility devices, has attracted the attention of many researchers all over the world for its superior performance and huge development potential. [0003] However, due to the very high power density of the wide bandgap compound semiconductor device, its heat density is also very high, resulting in a very large amount of heat generated during the operation of the device. If the heat cannot be dissipated...

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Problems solved by technology

[0003] However, due to the high power density of the wide bandgap compound semiconductor device, its heat density is also very high, resulting in a very large amount of heat generated by the device during operation. If the heat cannot be dissipated in time, the internal temperature of the device will rise. Affect the stability and reliability of the device, while limiting the further improvement of the output power of the device

[0004] In order to increase the output power of the device, one method is to increase the size of the device, that is, to increase the heat dissipation area and improve heat dissipation by enlarging the width of the entire semiconductor device, but this will make the entire semiconductor device very wide, making the aspect ratio of the semiconductor device It will be very large, resulting in increased difficulty of subsequent processes (such as cutting and packaging, etc.), reduced yield, and reduced performance (increased gate resistance or out-of-sync RF signal phase), etc., and the heat in the central area of ​​this semiconductor device still cannot Spread out in time, the center temperature is still higher, the edge temperature is lower, and the temperature distribution is still uneven

[0005] Another method is to use a substrate material with higher thermal conductivity, such as grinding off the silicon carbide substrate, and forming a diamond film on the back of the epitaxial layer by CVD (Chemical Vapor Deposition, chemical vapor deposition), sputtering or bonding. or diamond-like carbon, but increases process complexity and cost

[0006] Another method is to improve the heat dissipation of the package, such as optimizing the packaging process, using a shell structure with better heat dissipation, etc., but it does not solve the fundamental problem, and the temperature inside the device cannot be effectively and evenly distributed through the shell in a timely manner. Uneven temperature distribution, highest in the center

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