Thermal Stability of Al2O3-HfO2 Laminate, Hf-Al-O Alloy and HfO2 Thin Films on Si

The thermal stability and interfacial reaction of Al2O3-HfO2 laminate, Hf-Al-O alloy and HfO2 thin ¯lm deposited on p-Si(100) by the atomic-layer deposition (ALD) method were investigated by using X-ray photoelectron spectroscopy (XPS). All these thin ¯lms were quite thermally stable below 600 ±C. After annealing at 900 ±C, the formation of Hf-silicates in the interface was eectively suppressed in Hf-Al-O thin ¯lm, but was enhanced in Al2O3-HfO2 laminate ¯lm and HfO2 thin ¯lm. In the case of laminate, after in-situ annealing at 900 ±C, the layered structure of the laminate ¯lm collapsed. In the case of Hf-Al-O alloy thin ¯lm, after in-situ annealing at 900 ±C, Hf-Al-O phase separation into HfO2 and Al2O3 occurred. In the case of HfO2 ¯lm, there was a transient formation of Hf-O rebonding before it was degraded into HfSi. Hf-Al-O thin ¯lm is thermally more stable than Al2O3-HfO2 laminate and HfO2 thin ¯lm. KCI Citation Count: 17