Resonant cavity complementary optoelectronic transistors

Abstract

The CMOS field effect transistors, used in microprocessors and other digital VLSI circuits, face major challenges such as thin gate dielectrics leakage and scaling limits, severe short channel effects, limited performance improvement with scaling, complicated fabrication process with added special techniques, and surface mobility degradation. This disclosure proposes a new CMOS-compatible optoelectronic transistor. The current is much higher than the MOS transistors, due to the high carrier mobility with bulk transportation. The optoelectronic transistors are scalable to the sub-nanometer ranges without short channel effects. It is also suitable for low power applications and ULSI circuits. The new transistor consists of a laser or LED diode as drain or source, and a photo sensor diode (avalanche photo diode) as source or drain. The transistor is turned on by applying a gate voltage, similar to the CMOS transistors, and a laser or LED light signal is sent to the nearby photo diode, causing an avalanche breakdown and high drain current. The transistor is surrounded by dielectrics and metal isolations, which serve as a metal box or cavity, so the generated laser or LED lights are confined and reflected back from the metal. The drain current increases exponentially with the drain or gate voltage. This exponential drain current vs. drain or gate voltage characteristics makes the optoelectronic transistor run much faster than the transitional linear MOSFET. The optic transistor current-voltage characteristics are totally different from transitional CMOS transistors.