PRESSURE OF PHOSPHORUS IN EQUILIBRIUM WITH SOLID INP AT DIFFERENT TEMPERATURES

The phosphorus pressure in equilibrium with solid InP heated at temper atures of up to 980-degrees-C was measured using a new-concept apparat us appositely designed and manufactured. With this apparatus, all the difficulties inherent to handling of phosphorus vapor and high tempera tures were overcome without making use of complicated devices such as quartz membranes or helix. This has allowed a reproducible series of m easurements of the phosphorus equilibrium pressure to be made. This pr essure was found to vary exponentially between 2 and 550 mbar as the I nP temperature grows from 800 to 980-degrees-C. The results are of pra ctical interest, particularly if one considers the recent technologica l efforts for growing InP single crystals under P atmosphere and for o btaining semi-insulating undoped InP by thermal annealing under P coun ter pressure.