PSP Model-Based Emulation Method for Geometry-Dependent Cryogenic Effects in 28-nm Bulk CMOS Technology

An emulation method for geometry-dependent cryogenic effects in bulk CMOS technology based on the PSP model is proposed. By properly selecting and adjusting geometry- and temperature-independent/dependent parameters in the PSP model, characteristic changes of transistors due to cryogenic effects can be emulated using existing commercial process design kits (PDKs). To emulate the increased threshold voltage (Vth) and mobility (μ) due to cryogenic effects, the parameter values of VFBO, STBETO, and STMUEO are modified. To model the geometry-dependent cryogenic effects, the parameter values of STVFBLW and STVFBL for Vth and STBETL for μ are modified. To validate the proposed method, a 23-stage inverter-based ring oscillator was designed and evaluated, using the proposed emulation method based on commercial PDK of 28-nm bulk CMOS technology.