HOLE CONFINEMENT IN BORON DELTA-DOPED SILICON QUANTUM-WELLS STUDIED BY DEEP-LEVEL TRANSIENT SPECTROSCOPY

Observation of the hole-confinement effect in boron delta-doped Si qua ntum wells has been demonstrated using the deep-level transient spectr oscopy (DLTS) technique, based on the concept of treating the quantum well as a big ''trap.'' For the same doping thickness but different do ping densities, i.e., different boron sheet doping concentrations, the well depths acid the subband positions are different and the peak shi ft of DLTS spectra is thus expected and is observed experimently for t wo samples with sheet doping concentrations of about 2.4 x 10(13) and 6.0 x 10(13) cm(-2), respectively. A self-consistent calculation of th e subbands in the quantum wells verifies that the detected activation processes in DLTS correspond to the hole emissions from the hole groun d states in the delta-doped quantum wells to the top of the wells.