Processing and Characterization of Ultra-Small Silicon Devices

Processing, design, and characterization issues are discussed for advanced field-effect (FET) and bipolar transistors. Results are presented from work on N-channel FET's with gate lengths below 0.1 μm, and on the role that polysilicon emitter contacts play in high current, high speed bipolar devices. For FET's over 750mS/mm transconductance was achieved at liquid nitrogen temperature operation. In the case of bipolar devices it was found that maximizing the gain enhancement derived from the polycrystalline/single-crystal interface without regard to resistive effects does not lead to the highest performance in submicron transistors. Based on previous experience and on our recent work, we believe that silicon technology faces no insurmountable obstacles as it progresses into the deeply submicron regime.