Novel Ultra-Thin Base NDR HBT Fabricated by Common Mesa Process

Negative Differential Resistance (NDR) Heterojunction Bipolar Transistor (HBT) holds high speed, high frequency characteristics of HBT and bistability, self-latching characteristics derived from NDR, is compatible with HBT manufacture technique, and has good research and application value. Based on the thought that Early effect causes very thin base reach-through, bipolar operation mode changes to barrier transistor operation mode and NDR appears, a novel 8 nm base NDR HBT has been fabricated through special design of device structure and common HBT mesa process, which has distinct and special variable voltage-controlled NDR characteristic and current-controlled NDR characteristic. The Peak to Valley Current Ratio(PVCR)voltage-controlled NDR character is higher than 1 000. All of phenomena are reported for the first time.