Preservation of lndium phosphide substrates: The ln-Sn-P melt re-visited.

Using Auger electron spectroscopy and secondary ion mass spectrometry, we have detected very high levels of tin (~ 10(21)/cm(3) on (100) lnP substrates preserved at high temperatures (650 - 700degrees C) with phosphorus vapor supplied by an ln-Sn-P solution. Depth profiling through lnP epilayers grown on preserved substrates, however, indicates no tin build-up at the epilayer/substrate interface. Surface studies and depth profiling of control samples reveal that the tin accumulated during preservation is restricted to the very surface (~ 10 angstroms) and readily dissolves into an ln-P melt.