Integration of isolated RF-LDMOS transistors in a 0.25 µm SiGe:C BICMOS process

Isolated LDMOS transistors with thin gate oxides and good RF performance are key components in integrated RF circuits where large voltage shifts are required for the circuit functionality. We demonstrate the modular integration of isolated NLDMOS and PLDMOS focusing on maximal RF performance into an advanced industrial 0.25 μm SiGe:C BICMOS process. A boundary condition for device construction was a limit for maximum deep n-well implantation energy of 750keV. The achieved values BV_DSS/f_T/f_MAX of -21V/10GHz/35GHz for the PLDMOS and 16V/30GHz/53GHz for the isolated NLDMOS, respectively, reflect the excellent RF performance obtained.