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 °C. 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 °C 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 °C. 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.