Pressure of phosphorus in equilibrium with solid InP at different temperatures

The phosphorus pressure in equilibrium with solid InP heated at temperatures of up to 980 °C was measured using a new‐concept apparatus appositely designed and manufactured. With this apparatus, all the difficulties inherent to handling of phosphorus vapor and high temperatures were overcome without making use of complicated devices such as quartz membranes or helix. This has allowed a reproducible series of measurements of the phosphorus equilibrium pressure to be made. This pressure was found to vary exponentially between 2 and 550 mbar as the InP temperature grows from 800 to 980 °C. The results are of practical interest, particularly if one considers the recent technological efforts for growing InP single crystals under P atmosphere and for obtaining semi‐insulating undoped InP by thermal annealing under P counter pressure.