DETERMINATION OF THE VALENCE-BAND OFFSET OF SI SI0.7GE0.3/SI QUANTUM-WELLS USING DEEP-LEVEL TRANSIENT SPECTROSCOPY/

Deep level transient spectroscopy (DLTS) was performed on p-isotype Si /SiGe/Si Schottky barrier diodes in order to obtain the valence band o ffset between Si and SiGe. A single strained Si0.7Ge0.3 layer was plac ed in such a depth in Si so as to be able to fill and empty the quanti zed SiGe well during the transient capacitance procedure. Broad capaci tance transient peaks were obtained and interpreted as being due to th e capture of holes by the quantum well. The broadness of the peaks was explained by thickness variations of the SiGe layer. From the depende nce of the high temperature side of the DLTS peak on the rate window a valence band offset of 220 +/- 20 meV was evaluated.