Study On System-Level Simulation Of Mems Devices

With the development of MEMS technology, Finite Element Analysis (FEA) cannot meet the requirement of design for complex devices. The system-level simulation and analysis play a more and more important role in the design and optimization of devices. Building the macromodels of the MEMS devices is one of the critical techniques of system-level simulation. The approach of equivalent circuit representation is adopted to build the macromodels of the basal MEMS devices in this paper. Polynomial controlled-sources of SPICE are used to build and simplify the circuit structure.The parallel plate electromechanical transducer of lumped-parameter devices is studied first in the paper. Two kinds of parallel plates including transverse and longitudinal transducers are introduced. The characteristic equations of electromechanical coupling parts are derived with the energy method. Comb resonator and ideal electromechanical sensor are taken as two examples and their large-signal macromodels for equivalent circuit representation are then built. The simulation results are verified by the theoretical analysis. The idea of building the macromodels for the equivalent circuit representation of lumped-parameter MEMS devices is put forward ultimately.The transducers of beam and membrane are the common distributed-parameter structures in MEMS devices. For the two structures of cantilever beam and clamped-clamped beam, small-signal multi-modal macromodels for equivalent circuit representation are built by using the controlled-sources of SPICE with F-V and F-I analogy, respectively. For the rectangle membrane with four sides fixed, the small-signal macromodel for two-dimensional equivalent circuit array representation is built by adopting F-I analogy for the first time. System-level simulation with SPICE and verification with CoventorWare are taken for all the macromodels built above.According to the macromodels of equivalent circuit representation for basal MEMS devices built, IP libraries are created with the netlist description of SPICE. The IP cells are then packaged for the system-level's calling. The software "MEMS-IP Interface" for interface's design from devices' parameters to corresponding netlists' creation is developed with C++.A relatively complete technical channel from devices' modeling to system-level's calling is established in this paper and the design ideology of "Built by the expert, used by the non-expert" is elementarily realized for MEMS professional system.