CROSS-SECTIONAL TRANSMISSION ELECTRON-MICROSCOPIC STUDY OF AU/GAP AND AU/INP CONTACTS

Au(80 nm)/GaP(111) samples were heat treated in forming gas in the temperature range of 450-550-degrees-C. Very thin elongated alpha-Au(Ga) grains were grown into the GaP at 475-degrees-C as a result of the interface reaction between Au and GaP. A surface (interface) energy driven grain growth in Au-Ga solid solution was observed after annealing at 500-degrees-C. At 525-degrees-C long, flat grains were formed from the thin elongated ones of alpha-Au(Ga). At 550-degrees-C the metallization melted due to its high Ga content. During the solidification the shape of drops was preserved, and the metallization consisted of Au2Ga and Au7Ga2 grains. Au(100 nm)/InP(111) samples were annealed at 375 and 400-degrees-C in forming gas for 10 min. Elongated crystals grown into the InP substrate due to the interaction between gold and InP were observed. Au9In4 grains are situated in these pits in the matrix of the Au2P3 monoclinic phase.