High voltage transistor

Abstract

The invention provides a high-voltage transistor which comprises a substrate, a first well region and a second well region which are formed in the substrate, a source electrode located in the first well region, a drain electrode located in the second well region, and a gate electrode located, between the source electrode and the drain electrode, on the substrate, wherein the first well region has a first doping type (N type or P type), the second well region has a second doping type (P type or N type) opposite to the first doping type, the first well region and the second well region are spaced from each other by a predetermined distance to form a buffer channel, and the buffer channel is located below the gate electrode. Due to the arrangement of the buffer channel in the high-voltage transistor, PN junction leakage current at the joint of the first well region and the second well region can be reduced, junction capacitance can be reduced, source-drain breakdown voltage can be increased, and the hot carrier injection phenomenon can be improved.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a high-voltage transistor. Background technique [0002] In the application of high voltage transistor (High Voltage MOSFET) devices, source-drain breakdown voltage (BVDS) is one of the most important parameters. The higher the source-drain breakdown voltage, the better the performance of the high-voltage transistor. Moreover, it is necessary to ensure that the high-voltage transistor has an appropriate saturation current (Idsat) in the on state and at the same time reduce the off current (Ioff) as much as possible. In addition, since the high-voltage transistor device will form a very high electric field during use, in addition to the source-drain breakdown voltage, the hot carrier injection effect must also be considered. [0003] figure 1 It is a cross-sectional view of an existing high-voltage transistor. Such as figure 1 As shown, a first well region...

AI Technical Summary

Problems solved by technology

Although this can increase the source-drain breakdown voltage, it sacrifices the saturation current of the high-voltage transistor, resulting in higher PN junction leakage current and larger PN junction parasitic capacitance

In addition, the method of increasing the doping concentration of the channel region will increase the electric field strength of the channel region, further deteriorating the hot carrier injection effect

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