US Patent 11942540 Semiconductor device and method for manufacturing the same

A semiconductor device having an LDMOS transistor can include: a first deep well region having a first doping type; a drift region located in the first deep well region and having a second doping type; and a drain region located in the drift region and having the second doping type, where the second doping type is opposite to the first doping type, and where a doping concentration peak of the first deep well region is located below the drift region to optimize the breakdown voltage and the on-resistance of the LDMOS transistor.