Si/SiGe resonant interband tunnel diodes grown by large-area chemical vapor deposition

Si/SiGe resonant interband tunnel diodes were successfully technology transferred from low-temperature molecular beam epitaxial growth to chemical vapor deposition (CVD) on 200-mm diameter p-doped silicon wafers in a production style reactor. The resonant interband tunnel diode structure consists of a p⁺-i-n⁺ diode that incorporates vapor phase doped δ-doping to enhance quantum mechanical confinement and tunneling probability. The tunneling barrier thickness was varied from 2 nm to 8 nm and a record high peak-to-valley current ratio of 5.2 for a CVD process is reported for a 6 nm barrier thickness. The CVD reactor is an active integral tool within a 200mm full CMOS process line and is suggestive that Si/SiGe RITDs could be seamlessly integrated into a full hybrid CMOS process flow.