A MOSFET device having a recessed drain structure with bidirectional level transfer

Abstract

The present invention provides a MOSFET device having a recessed drain structure with bidirectional level transfer, comprises a p-type substrate, a p-type epitaxial layer, an n-type drift layer, a p-type body region, a groove first drain, a first drain N + implantation region, a groove second drain, a second drain N + implantation region, a groove gate, a gate oxide dielectric layer, a p-type lightly doped first RESURF region and a p-type lightly doped second RESURF region; The invention realizes the complete symmetrical structure of the MOSFET. On the premise of guaranteeing a certain depth of the gate electrode and the drain trench, the device can realize the bidirectional level transmission and reduce the unavoidable loss when the circuit is used for the bidirectional level transmission. By using groove technology, the gate control ability of the device is improved, the transmission distance of the carrier is reduced, the on-resistance is reduced, and the reliability of the device is improved. By using RESURF technology, the electric field of surface breakdown is ensured to be increased, and the on-resistance of the device is also reduced, which further improves the reliabilityof 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...

AI Technical Summary

Problems solved by technology

Most of the MOSFETs for bidirectional level transmission are realized by n-channel enhanced Si MOS plus circuits, and no MOSFETs with bidirectional transmission characteristics have appeared yet.

Bidirectional level transmission through circuits has many disadvantages, such as high requirements on the breakdown characteristics and transmission characteristics of the devices participating in the transmission, or the threshold loss is relatively large when the circuit is simple, and the circuit is complicated when the threshold loss is controlled.

Images