(Invited) Atomic Layer Deposition of HfO2 Using HF Etched Thermal and RTP SiO2 as Interfacial Layers

Abstract

Atomic Layer Deposition (ALD) of HfO2 on Si substrates requires an interfacial oxide layer, which should be full of hydroxyl groups (-OH groups) or hydrophilic. Chemical oxide grown by SC1 solution is widely used as an ideal interfacial layer. It was reported that thermal SiO2 and RTP SiO2 are not good as interfacial layers because they are lack of OH groups. In this research, we found that diluted HF etching of thermal SiO2 and RTP SiO2 could create hydrophilic surfaces, which could be used as interfacial layers for ALD of HfO2. The electrical properties of the HfO2 grown on etched thermal and RTP SiO2 is not significantly degraded comparing to the HfO2 grown on chemical oxide.