Design Of 30V,2.4GHz SOI-LDMOS

With the development of the telecommunication, RF power amplifier has a promising future. And for high performance integrated RF circuits, thin-film SOI technology is a best choice. As the last level power MOSFET of the RF power amplifier, SOI-LDMOS affects the amplifier's performance even the whole circuit's performance. RF circuits need SOI-LDMOS to have high breakdown voltage (30V) and high cut-off frequency (2.4GHz). But the technology of high frequency device that can withstand high breakdown voltage is complex and difficult to be compatible with standard SOI-CMOS technology. This is also one of the reasons of the high cost. Thus it is important to design a power device which has high breakdown voltage, high cut-off frequency and satisfy the demand and is compatible with standard SOI-CMOS.SOI-LDMOS is adopted by RF power amplifier because of its excellent isolation performance and small parasitical effect. In this thesis, a RF RESURF SOI-LDMOS which has high breakdown voltage (more than 30V) and high cut-off frequency (more than 2.4GHz) is designed. Firstly, in the introduction section, the history of invention of the RESURF SOI-LDMOS and the application are introduced. Then in the first chapter, the device is modeled to get approximate value of each parameter. In the second chapter, Tsuprem-4 and Medici are used to optimize the values got in the first chapter. The parameter of the SOI-LDMOS is extracted in the third chapter, some effects such as Kirk effect, floating body effect, self-heating effect and hot carrier effect etc., are introduced and method to prevent them is also showed in this chapter.The SOI-LDMOS designed in this thesis has a 70V breakdown voltage in off state and 50V breakdown voltage in on state, 13.6GHz cut-off frequency. And it is compatible with standard SOI-CMOS. So it satisfies the demand.