Multi-gate SOI-LDMOS device structure

Abstract

The invention provides a multi-gate SOI-LDMOS device structure which comprises an SOI substrate, an active region and a polysilicon gate. The SOI substrate comprises a silicon substrate body, an oxygen buried layer and a top silicon layer, the active region is formed in the top silicon layer and comprises a source region, a channel region, a drift region, a shallow doping drain region and a drain region, the source region, the channel region, the drift region, the shallow doping drain region and the drain region are sequentially connected, the polysilicon gate comprises a gate-oxide layer and a polysilicon layer, the gate-oxide layer is combined to the surface of the channel region, the polysilicon gate is separated by at least one dielectric layer into two short gate structures, and heavy doping regions inversed with the channel region in doping type are formed corresponding to the position, below the dielectric layer, in the channel region. The multi-gate SOI-LDMOS device structure has the advantages of being high in breakdown voltage, good in transconductance characteristic, small in positive break-over resistance, low in self-heating effect and the like. As the heavy doping regions inversed with the channel region in doping type are formed between short gates, when a device is irradiated, the heavy doping regions serve as recombination centers, the large number of recombination centers are provided for electron hole pairs generated by irradiation, and the whole radiation resisting performance of the device is accordingly improved.

Description

technical field [0001] The invention relates to a semiconductor device structure, in particular to a multi-gate SOI-LDMOS device structure. Background technique [0002] Contemporary power integrated circuits are widely used in daily consumption fields such as power control systems, automotive electronics, display device drivers, communications and lighting, as well as in many important fields such as national defense and aerospace. With the continuous expansion of its application fields, the high voltage of its core parts The requirements for devices are getting higher and higher. In particular, it is required to reduce the on-resistance of the device as much as possible under the premise of ensuring the breakdown voltage to improve device performance and reduce power consumption. Traditional high-voltage devices have a "silicon limit" relationship (Ron,sp∞BV 2.5 ), as the breakdown voltage of the device increases, the specific on-resistance of the device increases sharply...

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Problems solved by technology

[0007] In view of the above-mentioned shortcoming of the prior art, the object of the present invention is to provide a multi-gate SOI-LDMOS device structure, which is used to solve the transconductance characteristics, forward conduction resistance, Problems such as self-heating effect and poor overall radiation resistance

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