Integrated enhancement type and depletion type vertical bilateral diffusion metallic oxide field effect pipe

Abstract

The invention discloses an integrated enhancement-mode and depletion-mode vertical double diffusion metal oxide field effect tube, which comprises a heavily doped N-shaped substrate, a N-shaped extension equipped on the N-shaped substrate, an enhancement-mode vertical double diffusion metal oxide field effect tube and a depletion-mode vertical double diffusion metal oxide field effect tube equipped on the N-shaped extension, wherein an isolation structure is provided between the enhancement-mode vertical double diffusion metal oxide field effect tube and the depletion-mode vertical double diffusion metal oxide field effect tube. The isolation structure comprises floating P-shaped trap, a silicon dioxide dielectric layer and a polysilicon field plate, wherein the silicon dioxide dielectric layer is equipped on the upper end of the floating P-shaped trap, and the polysilicon field plate is equipped in the silicon dioxide dielectric layer. Comparing with the prior art, the invention uses an isolation structure to integrate the enhancement-mode vertical double diffusion metal oxide field effect tube and the depletion-mode vertical double diffusion metal oxide field effect tube on one chip, which is helpful for integration and miniaturization of system.

Description

technical field [0001] The invention relates to an integrated field effect transistor which integrates two kinds of vertical double-diffusion metal oxide field effect transistors of enhancement type and depletion type in one chip, which is suitable for switching power supply system. Background technique [0002] Mosfet high-voltage devices have the advantages of good switching characteristics and low power consumption. More importantly, metal-oxide-semiconductor high-voltage devices are easily compatible with standard low-voltage metal-oxide-semiconductor processes, reducing chip production costs. Metal-oxide-semiconductor high-voltage devices are developing in two directions: lateral metal-oxide-semiconductor high-voltage devices and vertical conductive metal-oxide-semiconductor high-voltage devices. Among them, the vertical double-diffused metal oxide field effect transistor transfers the drain region, drift region and channel region from the surface of the silicon wafer t...

AI Technical Summary

Problems solved by technology

However, once the enhancement type and the depletion type vertical double-diffused MOSFET are integrated, punch-through phenomenon is easy to occur, so the isolation between the two is a problem that must be solved

Images