Power semiconductor device and manufacturing method thereof

Abstract

The invention discloses a power semiconductor device. The device comprises a main body, an oxide layer, a grid, and an isolated layer. The main body includes: a substrate; an injection region, which is formed on a portion of the substrate; a diffusion region, which is formed on a portion of the substrate; and a source region, which is embedded into portions of upper surfaces of the injection region and the diffusion region; besides, the substrate and the source region have same conductivity and the injection region and the diffusion region has conductivity that is opposite to that of the substrate and the source region. The oxide layer is formed on the main body and is transversely extended to areas of the injection region and the diffusion region. The grid is arranged on the oxide layer. And the isolated layer is formed on the grid and at side surfaces of the grid; and an enclosed space is formed by the isolated layer and the oxide layer, so that the grid is isolated from the main body. In addition, the isolated layer at least comprises two layers and all the layers are formed by different materials; one layer of the isolated layer is used for offsetting stresses generated by another layer of the isolated layer and another layer of the isolated layer has a blocking function. According to the power semiconductor device provided in the invention, steam and movable foreign ions like Na+ and K+ and the like can be effectively blocked; and moreover, the device has good heat stability and reliability as well as are suitable for working environments like a high temperature environment, a moisture environment and a larger power environment and the like.

Description

technical field [0001] The present invention relates to semiconductor devices in the technical field of microelectronics, in particular to a power semiconductor device and a manufacturing method thereof. Background technique [0002] like figure 1 As shown, the existing power metal-oxide-semiconductor field-effect transistor (i.e. PowerMOSFET power semiconductor device), insulated gate bipolar transistor (i.e. IGBT power semiconductor device) mainly includes a substrate 3, an implant formed on a part of the substrate 3 region 4, diffusion region 5, and source region 6 embedded in part of the upper surface of implantation region 4 and diffusion region 5. Substrate 3 and source region 6 have the same electrical conductivity, and implantation region 4 and diffusion region 5 It has the opposite conductivity; the oxide layer 7 formed on the body 100 extends laterally to the region of the implantation region 4 and the diffusion region 5; the gate 8 disposed on the oxide layer 7; ...

AI Technical Summary

Problems solved by technology

[0003] Most PowerMOSFET and IGBT power devices use single-layer phosphosilicate glass (PSG), but phosphosilicate glass (PSG) is easy to absorb water, so single-layer phosphosilicate glass (PSG) cannot effectively block water vapor and Na+, K+, etc. Move impurity ions, and have poor thermal stability and reliability, and are not suitable for working environments such as high temperature, humidity and high power

Images