LDMOS (laterally diffused metal oxide semiconductor) transistor and forming method thereof

Abstract

Disclosed are an LDMOS (laterally diffused metal oxide semiconductor) transistor and a forming method thereof. The LDMOS transistor comprises a semiconductor substrate, a body region and a drift region, a gate region, a source region, a base region, a drain region, a guide region and a barrier region; the body region and the drift region are located in the semiconductor substrate; the gate region located in the semiconductor substrate crosses the body region and the drift area; the source region and the base region are located in the body region; the drain region is located in the drift region; the guide region located below the body region and the drift region is connected with the body region and the drift region; the doping type of the guide region is opposite to that of the drift region; the barrier region located in the semiconductor region surrounds the body region, the drift region and the guide region; the doping type of the barrier region is opposite to that of the guide region. The LDMOS transistor can prevent leak current from entering the semiconductor substrate, and performance of the LDMOS transistor is improved.

Description

technical field [0001] The invention relates to the field of semiconductor manufacturing, in particular to an LDMOS transistor and a forming method thereof. Background technique [0002] Laterally Diffused Metal Oxide Semiconductor (LDMOS) transistors are mainly used in power integrated circuits, such as RF power amplifiers for mobile phone base stations, and can also be used in high frequency (HF), very high frequency (VHF) and Ultra-high frequency (UHF) broadcast transmitters and microwave radar and navigation systems, etc. LDMOS transistor technology brings higher power peak-to-average ratio, higher gain and linearity to a new generation of base station amplifiers, while bringing higher data rates for multimedia services. [0003] For a semiconductor device used as a power integrated circuit, its on-resistance (Rdson) and breakdown voltage (Breakdown Voltage, BV) are two important indicators to measure its device performance. For LDMOS transistors, it is generally desir...

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Problems solved by technology

[0005] When the above-mentioned existing LDMOS transistor is an LDNMOS transistor, the semiconductor substrate 100 is P-type doped, and the drift region 120 is N-type doped. At this time, a PN junction is formed between the two. When the drain region 121 receives a negative voltage, The PN junction will be opened, and current will flow into the semiconductor substrate 100, affecting the normal operation of the device

[0006] When the above-mentioned existing LDMOS transistor is an LDPMOS transistor, the semiconductor substrate 100 is N-type doped, the drift region 120 is P-type doped, and a PN junction is still formed between them (the direction is opposite to that of the LDNMOS transistor). , at this time, when the drain region 121 receives a positive voltage, the PN junction will be opened, and current will flow into the semiconductor substrate 100, affecting the normal operation of the device

[0007] It can be seen that the performance of existing LDMOS transistors needs to be improved urgently

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