High 5.2 peak-to-valley current ratio in Si/SiGe resonant interband tunnel diodes grown by chemical vapor deposition

Si/SiGe resonant interband tunnel diodes were fabricated using chemical vapor deposition (CVD) on 200-mm diameter p-doped silicon wafers. The resonant interband tunnel diode structure consists of a p+-i-n+ diode that incorporates vapor phase doped δ-doping to enhance quantum mechanical tunneling probability. The tunneling barrier thickness is varied from 2 nm to 8 nm, and a record peak-to-valley current ratio of 5.2 for a CVD process is reported for a 6 nm barrier thickness with a room temperature peak tunneling current of 20 A/cm2. The current density increases exponentially with spacer thickness reduction with a maximum value of 280 A/cm2 for a 2 nm barrier.