LDMOS (laterally diffused metal oxide semiconductor) field effect transistor with bulk electric field modulation function

Abstract

The invention provides an LDMOS (laterally diffused metal oxide semiconductor) field effect transistor with a bulk electric field modulation function. The LDMOS field effect transistor has the characteristic that a wide bandgap semiconductor SiC (silicon carbide) burying layer is formed under the drain end of the LDMOS field effect transistor by a heteroepitaxy technique; an internal high peak electric field under the drain end is led into the SiC burying layer, the characteristic of higher critical breakdown electric field (EC-SiC=3.0*106V / cm greater than EC-Si=3.0*105V / cm) of the SiC material is utilized, and the breakdown occurs in the SiC burying layer, so that the breakdown voltage of the LDMOS is effectively increased, and the property of the LDMOS field effect transistor is greatly improved.

Description

technical field [0001] The invention relates to the field of semiconductor devices, in particular to a lateral double-diffused metal oxide semiconductor field effect transistor. Background technique [0002] In the power monolithic integration technology, combined with isolation technology and high-voltage and low-voltage compatibility and other key processes, the integrated high-voltage power device is the core of the power integrated circuit (PIC). Due to the advantages of lateral double-diffused MOS (LDMOS) devices in terms of easy integration, good frequency characteristics, and low power consumption, LDMOS has been used as a key core device in high-voltage power integrated circuits (HVIC) and smart power integrated circuits (SPIC). In recent years, with the continuous development of power electronics, low-cost and high-reliability requirements have been put forward for core power devices such as lateral double-diffused MOS devices (ie, LDMOS). The field plate technolog...

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Problems solved by technology

[0003] However, experiments have shown that these improved devices are prone to breakdown in the drain body

After analyzing the reasons, the applicant believes that the body electric field of LDMOS has not been optimized, so that a peak electric field is formed under the drain of the device, resulting in breakdown

And since the Si material has a relatively low critical breakdown electric field of about 3.0×10 5 V / cm, making the performance of the device limited

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