The 5th International Symposium on IC Technology, Systems & Applications (ISIC-93)

Singapore, September 15-17, 1993, pp. 717-721.

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Base transit times in ballistic-base and graded-base heterojunction bipolar transistors are calculated using a regional ensemble Monte Carlo method. Somewhat realistic boundary conditions are used in carrier injection into the base region of the device. Optimum base transit times are obtained in various structures and base width-composition combinations, and related to the underlying physical mechanisms. The simulation results provide physical insights into the mechanisms in electron transport in the simulated structures as well as a general guidance for device parameter optimization. The method also demonstrates a general approach to modeling carrier transport in regional variable-band devices.

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