Change in Temperature Coefficient of Resistance of Heavily Doped Polysilicon Resistors Caused by Electrical Trimming

Abstract

The change in the temperature coefficient of resistance (TCR) of heavily doped polysilicon resistors caused by electrical trimming has been analyzed based on the melting-segregation model. The model reveals that the TCR of the boundary layers in a polysilicon resistor changes with trimming while that of grains remains the same. The theoretical expression for the change in the TCR of polysilicon resistors agrees well with the wide range of experimental data. The structures of the boundary layers and grains are discussed from the viewpoint of the TCR.