Mosfet device with grooved-drain structure with bidirectional level transfer

Abstract

The present invention provides a MOSFET device with a groove-type drain structure for bidirectional level transmission, comprising: a p-type substrate, a p-type epitaxial layer, an n-type drift layer, a p-type body region, a groove first drain, The first drain N+ injection region, the second drain of the groove, the second drain N+ injection region, the groove gate, the gate oxide dielectric layer, the p-type lightly doped first RESURF region and the p-type lightly doped second RESURF area; the present invention realizes the completely symmetrical structure of MOSFET, and under the premise of ensuring a certain gate and drain trench depth, the device can realize bidirectional level transmission, which reduces the inconvenience caused by using the circuit for bidirectional level transmission. Avoided loss; use groove technology to improve the gate control ability of the device, and at the same time reduce the carrier transmission distance and reduce the on-resistance, improve the reliability of the device; use RESURF technology to ensure the improvement of the surface breakdown electric field , At the same time, it can also reduce the on-resistance of the device, and further improve the reliability of the device.

Description

technical field [0001] The invention belongs to the technical field of power semiconductor devices, in particular to a MOSFET device capable of bidirectional level transmission. Background technique [0002] LDMOS is a power device with a double diffusion structure, which has good thermal stability, frequency stability and withstand voltage characteristics, so LDMOS devices are especially suitable for CDMA, W-CDMA, TETRA, digital terrestrial television, etc. that require a wide frequency range , high linearity and high service life requirements. The device is implanted twice successively in the same source / drain region, one with a higher concentration of arsenic, and one with a lower concentration of boron, followed by a high-temperature boost process. Since boron diffuses faster than arsenic, the gate A channel with a concentration gradient is formed under the boundary. To increase the breakdown voltage, there is a drift region between the active and drain regions. The d...

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