Annealing of defect density and excess currents in Si-based tunnel diodes grown by low-temperature molecular-beam epitaxy

Deep-level transient spectroscopy (DLTS) measurements were performed in order to investigate the effects of post-growth heat treatment on deep level defects in Si layers grown by low-temperature molecular-beam epitaxy (LT-MBE) at 320 degreesC. In the LT-MBE as-grown samples, two dominant divacancy-related complex defects, of which the possible origins are suggested as P-V (E center)+V-V (0/-) and V-V (-2/-) and others, were observed in P-doped n layers. When the as-grown samples were annealed at 700, 800, and 900 degreesC for 60 s by rapid thermal annealing, the total density of defects were decreased without generating other defects and most defects were annihilated at 900 degreesC. This study also compared the DLTS trends with performance of Si-based resonant interband tunnel diodes (RITDs) in terms of peak current density, valley current density, and peak-to-valley current ratio, which are closely related to the deep-level defects. The active regions of the RITDs were grown at the same substrate growth temperature and annealed at similar temperatures used in this DLTS study. (C) 2004 American Institute of Physics.