Extremely Low Electron Density in a Modulation-Doped Si/SiGe Two-Dimensional Electron Gases by Effective Schottky Gating

We reported an extremely low electron density (8.3 x 10(10) cm(-2)) of a modulation-doped Si/SiGe two-dimensional electron gas by Schottky gating. Effective Schottky gating with extremely low gate leakage current was enabled by low-temperature chemical vapor deposition epitaxial growth to suppress the surface segregation of phosphorus. Furthermore, an extremely high electron mobility of similar to 504,000 cm(2)/V-s at 0.3 K was also reported.