摘要
A 680 V LDMOS on a thin SOI with an improved field oxide（FOX） and dual field plate was studied experimentally.The FOX structure was formed by an ＂oxidation-etch-oxidation＂ process,which took much less time to form,and had a low protrusion profile.A polysilicon field plate extended to the FOX and a long metal field plate was used to improve the specific on-resistance.An optimized drift region implant for linear-gradient doping was adopted to achieve a uniform lateral electric field.Using a SimBond SOI wafer with a 1.5μm top silicon and a 3μm buried oxide layer,CMOS compatible SOI LDMOS processes are designed and implemented successfully. The off-state breakdown voltage reached 680 V,and the specific on-resistance was 8.2Ω·mm^2.
A 680 V LDMOS on a thin SOI with an improved field oxide（FOX） and dual field plate was studied experimentally.The FOX structure was formed by an ＂oxidation-etch-oxidation＂ process,which took much less time to form,and had a low protrusion profile.A polysilicon field plate extended to the FOX and a long metal field plate was used to improve the specific on-resistance.An optimized drift region implant for linear-gradient doping was adopted to achieve a uniform lateral electric field.Using a SimBond SOI wafer with a 1.5μm top silicon and a 3μm buried oxide layer,CMOS compatible SOI LDMOS processes are designed and implemented successfully. The off-state breakdown voltage reached 680 V,and the specific on-resistance was 8.2Ω·mm^2.
基金
Project supported by the National Natural Science Foundation of China(Nos.11175229,61006088)
