MOSFET device manufacturing method and MOSFET device

Abstract

The invention relates to the technical field of semiconductors and specifically relates to an MOSFET device manufacturing method and an MOSFET device. According to the method, epitaxial technologies are adopted, heavily doped N type wide-gap semiconductor material is used as a substrate; a voltage withstanding drift zone, a P type body zone epitaxial layer and an N+ source zone epitaxial layer are orderly formed via homoepitaxial operation, and a matrix is formed; photoetching and etching technology technologies are used for forming a gate zone groove and a Schottky groove on the matrix; a gate oxide layer is formed on an inner wall of the gate zone groove via thermal oxidization; a gate electrode is formed on an inner wall of the gate oxide layer via depositing, photoetching and etching operation; an outer surface of the gate electrode is subjected to passivation layer deposition operation, and a gate electrode insulation protective layer is formed through the photoetching and etching operation; a Schottky diode is formed after a surface of the Schottky groove is subjected to Schottky barrier metal deposition operation and annealing operation; the MOSFET device is finally obtained. Via use of the MOSFET device manufacturing method and the MOSFET device that are provided in the invention, impurity doping and diffusion technologies are not required, and reliability of the gate oxide layer can be improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor devices, in particular to a method for manufacturing a MOSFET device and the device. Background technique [0002] Wide bandgap semiconductor MOSFET (metal oxide semiconductor transistor) devices, especially silicon carbide MOSFET devices and gallium nitride MOSFET devices are power switching devices that have attracted much attention at present. Its driving circuit is very simple and is compatible with existing power devices. The compatibility of the driving circuit is good. [0003] However, there are two main technical problems in the design of wide bandgap semiconductor MOSFET devices: low channel electron mobility, which leads to large channel resistance of MOSFET; second, insufficient reliability of gate oxide under high temperature and high electric field . [0004] At present, there are two main solutions to the problem of low channel electron mobility: [0005] One is to choose a...

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Problems solved by technology

[0003] However, there are two main technical problems in the design of wide bandgap semiconductor MOSFET devices: low channel electron mobility, which leads to large channel resistance of MOSFET; second, insufficient reliability of gate oxide under high temperature and high electric field

[0005] One is to choose a suitable crystal orientation, because the electron mobility of different crystal orientations is different, and the mobility can differ by up to 5 times, so the crystal surface with high electron mobility is selected to form a channel; because the crystal orientation of silicon carbide is chaotic, so Crystal faces with high electron mobility are not easy to choose

[0006] The second is to improve the state of the channel interface and increase the electron mobility of the channel through a special annealing process; this special annealing process is inconvenient to operate

[0007] For the reliability of the trench gate oxide, the solution is mainly to use special gate oxide materials, such as AlN, AlON and other materials; but only relying on special gate oxide materials cannot well solve the problem of trench gate oxide reliability

[0008] In addition, there are still difficulties in the process of wide-bandgap semiconductor MOSFET devices. This difficulty mainly lies in the form of the PN junction. The PN junction requires a suitable impurity concentration and concentration distribution. The current solution is to use high-temperature and high-energy ion multiple implantation. Then perform high-temperature annealing; multiple injections of high-temperature and high-energy ions will damage the crystal lattice of wide-bandgap semiconductor materials, and the manufacturer needs to purchase new equipment or new materials, which will result in a large investment of fixed funds and increase the cost

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