Tem Observations of AG-TI Bilayers After Thermal Aging Treatment in a Reducing Ambient

Abstract

ABSTRACTTransmission electron microscopy (TEM) in both cross sectional and plan view is used to study the effect of annealing Ag-Ti bilayers deposited on SiO2/Si substrates in an NH3 ambient. The resulting structure, texture and grain size are investigated. Comparisons are made between films annealed at 400, 500 and 600 °C. Silver films show increasingly strong <111> texture with annealing temperature while exhibiting a bamboo-like grain structure at 600 °C. Considerable grain growth with lateral grain sizes of up to 5 times the thickness of the Ag film is observed at 600 °C. The grains typically extend through the Ag film thickness. The Ti/SiO2 interface uniformity and the absence of voids at the substrate surface are positive indicators of the role of titanium as a good adhesion promoter. At 600 °C, a uniform TiN encapsulation layer is observed on the Ag surface.