산소 플라즈마를 이용하여 원거리 플라즈마 원자층 증착법으로 형성된 하프늄 옥사이드 게이트 절연막의 특성 연구

Abstract

Hafnium oxide (HfO2) films were deposited on Si(100) substrates by remote plasma-enhanced atomic layer deposition (PEALD) method at 250°C using TEMAH [tetrakis(ethylmethylamino)hafnium] and O2 plasma. KfO2 films showed a relatively low carbon contamination of about 3 at %. As-deposited and annealed HfO2 films showed amorphous and randomly oriented polycrystalline structure, respectively. The interfacial layer of HfO2 films deposited using remote PEALD was Hf silicate and its thickness increased with increasing annealing temperature. The hysteresis of HfO2 films became lower and the flat band voltages shifted towards the positive direction after annealing. Post-annealing process significantly changed the physical, chemical, and electrical properties of HfO2 films. HfO2 films deposited by remote PEALD using TEMAH and O2 plasma showed generally improved film qualities compare to those of the films deposited by conventional ALD.