Homogeneity of thermally annealed Fe-doped InP wafers

Microdefects and electrical uniformity of InP annealed in phosphorus and iron phosphide ambiances

“…[1][2][3]. Nonuniformity of Fe-doping, striations, precipitates and Fe aggregation around dislocations are common defects in asgrown Fe-doped InP [4][5][6]. The electrical uniformity of as-grown Fe-doped SI InP substrate is poor due to the existence of these flaws.…”

“…In recent years, heat treatment of InP has been studied in order to produce SI material with a low Fe concentration [7][8][9][10][11] and improve the electrical uniformity of Fe-doped SI InP [5,12,13]. Annealing of undoped InP wafer in an iron phosphide ambiance has proved to be a promising method for the preparation of SI material with good uniformity [8,9,11].…”

Mechanisms of the semi-insulating conversion of InP by anelastic spectroscopy

“…Post-growth thermal treatments of the ingots at about 900 o C produce beneficial effects concerning defect annealing besides a resistivity increase, but cause inhomogeneities across the crystal diameter 2 and do not improve the Fe homogeneity. 3 Therefore, the thermal treatments have to be carried out on the wafers cut from the as-grown ingots; in this way the wafer homogeneity results improved 4 and the striations and other types of lattice imperfections may be annealed.…”

Semi-insulating InP wafers obtained by Fe-diffusion

“…This in turn leads to electrical properties different from wafer to wafer. In addition to that, other types of non-uniformities we usually present in as-grown Fe-doped InP: growth striations, dislwations decorated by microdefects, microprecipitates embedded in the crystal matrix and sometimes inclusions [2, 3]. Thermal treatments at about 900 "C, carried out on wafers, have proved to be affective in order to improve the material homogeneity: striations are readily eliminated and microdefects can be dissolved while the electrical characteristics arc generally improved.…”