SiGe HBTs on Bonded Wafer Substrates

摘要

Silicon germanium (SiGe) heterojunction transistors have been fabricated on bonded wafer, silicon-on-insulator substrates. The devices have application in low power, radio-frequency electronics. The transistors were fabricated on bonded substrates incorporating poly-Si filled, deeptrench isolation. A novel selective and non-selective low pressure chemical vapour deposition (LPCVD) growth process was used for the layers. Experimental transistors exhibit good uniformity across the wafers and collector currents are seen to be ideal, showing the expected enhancement for the SiGe devices compared to Si. Anomalies in device characteristics at high current levels are investigated.