Dynamic charge storage in 6H-silicon carbide: prospects for high-speed nonvolatile RAMs

Charge storage on p-n junctions in 6H-silicon carbide (SiC) has been investigated. Storage times in these devices are too long to be measured at room temperature, and most investigations were conducted at temperatures above 300 degrees C. Charge recovery in this regime is thermally activated with an activation energy close to half bandgap ( approximately=1.45 eV). Studies of different size devices indicate that the leakage current is dominated by generation at the SiO/sub 2/ passivated sidewalls, and is sensitive to the oxidation conditions (i.e., wet versus dry). A simple extrapolation of the high-temperature data yields a room-temperature storage time of several hundred thousand years.