Si-based resonant interband tunneling diodes (RITDs) grown on commercially available Si0.8Ge0.2 virtual substrates were studied. Peak-to-valley current ratios (PVCRs) were improved by utilizing strain induced band offsets to 3.5 with a peak current density (Jp) of 161 A cm 2. More specifically, a tensilely strained Si layer on the p -side and a compressively strained Si0.5Ge0.5 layer on the n -side were added to the design to form enhanced potential barriers away from the tunneling junction. The outside barriers deepen the respective hole and electron quantum wells and also block nonresonant tunneling current, which improved the PVCR significantly. However, due to the large surface roughness of the SiGe virtual substrates used in this study, the RITDs grown on Si 0.8Ge0.2 substrates exhibit a smaller PVCR overall than RITDs optimized on standard Si substrates. Better performance is expected by using higher quality SiGe substrates with smaller surface roughness.
|Journal||Applied Physics Letters|
|Publication status||Published - 2008|
|Publication type||A1 Journal article-refereed|
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)