Simulation of poly-contacted devices in two dimensions
Abstract
Polysilicon contacts have played an integral role in reducing device dimensions and increasing $\beta$'s in bipolar transistors for some time. However, the mechanisms by which the $\beta$ enhancement in bipolars and V$\sb{\rm oc}$ increases in solar cells occur is still a matter of some controversy. DAP2D (Device Analysis Program in 2 Dimensions) provides a significant analytical tool for the study of devices with thin insulating layers. It provides the capability of studying effects caused by the break up of the insulating layer, and effects from trap-assisted tunneling (ie. tunneling into interface states and then recombining), and changes in potential barrier heights and insulator thicknesses. Simulations performed with DAP2D on poly-contacted emitter bipolars have provided quantitative information on the dependence of the base current with the break up of the oxide, and effects from changes in barrier heights and thicknesses. It was found that the changes in the base current with the break up of the oxide for HF-cleaned bipolars correlates well with experiment.
Degree
Ph.D.
Advisors
Gray, Purdue University.
Subject Area
Electrical engineering
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