Journal of Crystal Growth, Vol.237, 1697-1700, 2002
InP melts: investigation of wetting between boat materials in Bridgman growth
InP crystals were grown by the Bridgman method under controlled phosphorus vapor pressure. The dislocation density of the intentionally undoped crystal grown in a quartz boat was higher than that of the crystal grown in a pBN boat. The excess stress due to sticking between the melt and the boat was attributed to multiple dislocations. The wetting was investigated by observing the contact angles on the quartz or pBN plate in phosphorus vapor ambient in a closed ampoule. The melt became a sphere. The contact angles of 140-150degrees indicated the adhesive wetting on both materials. The excess thermal stress estimated from the difference of the thermal expansion coefficient between InP and quartz has sufficient strength to generate the dislocations. There was no significant difference between the contact angle of the quartz and pBN. The contact angle did not change when the vapor pressure decreased. The higher etch pit densities at lower or higher phosphorus vapor pressure should not be attributed to the difference of wetting. (C) 2002 Elsevier Science B.V. All rights reserved.