Ultrathin highly uniform Ni(Al) germanosilicide layer with modulated B8 type Ni5(SiGe)3 phase formed on strained Si1-xGex layers

摘要

We present a method to form ultrathin highly uniform Ni(Al) germanosilicide layers on compressively strained Si1-xGex substrates and their structural characteristics. The uniform Ni(Al) germanosilicide film is formed with Ni/Al alloy at an optimized temperature of 400 °C 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 Si1-xGex layer is conserved, which provides a great advantage for device application.