Mosfet devices and fabrication methods using single crystal substrates as epitaxial regions

Abstract

This creation discloses a MOSFET device with a single crystal substrate as the epitaxial region and its fabrication method. The fabrication method includes: fabricating gate interconnect structures, trench gates, and voltage resistant rings on a high resistivity substrate; Forming body and source regions; Deposition of isolation layer and fabrication of gate interconnect contacts, source contacts, and cutoff ring contacts; Produce gate metal, source metal, and cutoff ring metal; Thinning the back of the substrate and forming a drain metal. In this creation, a high resistivity substrate is used instead of a low resistivity substrate, and the original trapezoidal doping concentration of the substrate is redistributed through diffusion through high-temperature steps in the manufacturing process, thereby obtaining a doping concentration equivalent to a voltage resistant layer on the substrate and achieving the required voltage resistance specifications; Due to the absence of epitaxial layer growth, the manufacturing process has been reduced, resulting in lower production costs.

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