Patent ID: 10427929

Abstract:
A cap wafer bonded to a device wafer by a metal polysilicon germanium material to form a sealed chamber around a semiconductor device is provided. On the cap wafer, a stack of silicon (Si), polycrystalline silicon germanium (SiGe), and polycrystalline germanium (Ge) is formed. This stack of material layers is formed to intentionally have a roughened germanium surface. A metal structure is formed on a second wafer, having an anti-stiction coating layer on the surface of the metal structure. A metal silicon germanium bonding material is formed by placing the metal structure and germanium structure in contact and applying heat and pressure. The roughened germanium layer penetrates the anti-stiction coating layer upon application of the pressure. The germanium that penetrates to the metal is free of interfacial anti-stiction coating and allows for eutectic bond formation upon application of heat.