Technology Independent Device Modeling for Simulation of Integrated Circuits for FET Technologies

A novel approach to device modeling for circuit simulation of integrated circuits is presented. This approach is based on general nonlinear network models in tensor product spline representation. As a consequnce this device modeling approach is technology independent and automatable. Tensor product spline representations of nonlinear branch elements are particularly useful, since the controlling variables are typically directionally dominant and only low rank tensors are needed. The basic properties of splines are reviewed for circuit simulation applications. Device model generation, software implementation, user interfaces and the circuit simulation environment within SPICE are described in detail. Realistic comparisons with conventional device models are given. The approach has been applied to several integrated circuit technologies (1/2-μm silicon MESFET logic, 7-μm CMOS/SOS logic, and 5-μm metal gate bulk silicon CMOS logic). Device models and simulated circuit results are in all cases in excellent agreement with measured device and circuit characteristics. This novel device modeling approach is particularly suitable for circuit design in quickly changing technological environments and for submicron VLSI.