Reproducibility in the fabrication of undoped semi-insulating InP

Various annealing conditions for realizing the fabrication of undoped semi-insulating (SI) InP has been systematically studied in our laboratory for several years. In the present paper, these results are reported. It was found that by annealing at 950/spl deg/C for 40 hrs under the phosphorus vapor pressure of 1 atm, the reproducible preparation of undoped SI InP can be achieved with the maximum number of 30 two-inch diameter wafers per batch. It was also found that a multiple-step wafer annealing (MWA) is very effective in improving the uniformity of electrical properties.