Mesh Zoning Method for Electro — Thermal Analysis of Submicron Si MOSFET

Abstract

The results of electro — thermal analysis, which is widely known as hydrodynamic model, are strongly dependent on the mesh size of model. However, the theory and method of accurate mesh size have not investigated. In this paper, we presented the calculation errors caused by the mesh size by using several mesh size models. The calculation results show that the mesh size for lateral direction, i.e. direction from the source electrode to the drain electrode in MOSFET, does not strongly affect the calculated characteristics of MOSFET. On the other hand, the calculation results strongly depend on the mesh size for vertical direction, i.e. direction from the gate oxide to the bottom surface in MOSFET. Here, we proposed the mesh zoning method for electro — thermal analysis, which was derived from the theory of the semiconductor physics. The calculation results with our mesh zoning method showed good accuracy compared to the results of the fine mesh. Since the mesh zoning means the reduction of mesh number, as a result, our mesh zoning method could reduce the calculation time by at least 30 times.