THE DETERMINATION OF VALENCE-BAND DISCONTINUITIES IN SI SI1-XGEX/SI HETEROJUNCTIONS BY CAPACITANCE-VOLTAGE TECHNIQUES/

Capacitance-voltage (C-V) profiling has been used to measure the appar ent carrier concentration profiles in Si/Si1-xGex/Si structures for a range of Ge Percentages. Using Kroemers analysis, good agreement has b een found between theoretical valence band offsets and those determine d from the experimental data. The validity of Kroemers analysis has be en assessed in the presence of traps using a C-V simulation program. U nder certain circumstances, large errors occur in the extracted valenc e band offset due to distortion of the apparent carrier concentration profile by traps. It is proposed that the experimental data presented here falls into a regime where minimal distortion is to be expected an d is reflected by the accuracy of the extracted valence band offsets.