Undoped semi-insulating InP by high-pressure annealing

Abstract

Undoped semi-insulating (SI) InP wafers were obtained by high-temperature annealing under high phosphorus over pressure. These wafers show resistivities higher than 107 Ω cm, with mobilities greater than 4000 cm2 V−1 s−1. The SI properties could be held even after cap annealing with SiNx films at 700 °C for 15 min. The activation energy of deep levels causing the semi-insulation was estimated as 0.64 eV. Photoluminescence measurements made on undoped SI InP show hitherto unknown peaks in the long wavelength region between 1000 and 1400 nm.

Fabrication of undoped semi-insulating InP by multiple-step wafer annealing

“…Fe-doped SI InP has however various disadvantages such as the nonuniformity of electrical properties along crystal growth axis due to Fe segregation, 1 out-diffusion of Fe into epitaxial layers, 2 low activation efficiency of ion implantation, 3 formation of bright spots in substrates, and slip-lines in epitaxial layers. 4 Undoped SI InP, which can be realized by high temperature wafer annealing 5,6 is becoming a promising candidate for replacing conventional Fe-doped InP. The reproducible preparation of undoped SI InP was however difficult and the resistivity (ρ) and the mobility (µ) were largely varied (ρ: 2.6 × 10 3 -2.4 × 10 7 Ω cm, µ: 2080-4740 cm 2 /Vs).…”

Semi-Insulating Behavior of InP Wafers Prepared by Phosphorus Vapor Pressure Controlled Wafer Annealing

“…For the past decades, various authors have reported the preparation of undoped high resistive or SI InP by wafer annealing [8][9][10][11][12][13], but the reproducibilities have not been enough and moreover the mechanisms of semi-insulation have not been clear yet. In order to realize the reproducible preparation of extremely low Fe doped SI InP, it is necessary to determine suitable annealing conditions for it.…”

Effect of annealing conditions on the uniformity of undoped semi-insulating InP

“…with the carrier concentration of (3)(4)(5) Annealed wafers were removed from the ampoule and they were etched by 50 pm thickness.…”

“…It was recently found that undoped semi-insulating InP can be realized when undoped conductive InP is annealed under phosphorus vapor pressure (4,5). The reproducibility of this procedure however was not satisfactory, and the practical use was in delay.…”