Ultrathin highly uniform Ni(AI) germanosilicide layer with modulated B8 type Ni_5(SiGe)_3 phase formed on strained Si_(1-x)Ge_x layers

摘要

We present a method to form ultrathin highly uniform Ni(Al) germanosilicide layers on compressively strained Si_(1-x)Ge_x substrates and their structural characteristics. The uniform Ni(Al) germanosilicide film is formed with Ni/Al alloy at an optimized temperature of 400 ℃ with an optimized Al atomic content of 20 at. %. We find only two kinds of grains in the layer. Both grains show orthogonal relationship with modified B8 type phase. The growth plane is identified to be {10-10}-type plane. After germanosilicidation the strain in the rest Si_(-1x)Ge_x layer is conserved, which provides a great advantage for device application.