高性能HfAlO介质薄膜的制备

利用超高真空电子束蒸发法制备了可替代SiO2作为栅介质的HfAlO膜.薄膜的化学组成为(HfO2)(Al2O3)2,900℃退火处理后仍然呈现非晶状态,而且表面平滑.介电常数为12.7,等效氧化物厚度2 nm,固定电荷密度4×1012cm-2,2 C栅偏压下漏电流为0.04 m A/cm2.后退火处理能有效降低固定电荷密度和泄漏电流密度,但会造成界面SiO2的生长.

Preparation of High-Quality Hf-Aluminate Films by EB-PVD

Hf-aluminate films, a potential replacement for SiO2 as gate dielectrics, were deposited on Si substrate by ultra-vacuum electron beam evaporation (EB-PVD) method. The film with a chemical composition of (HfO2)(Al2O3)2,remained amorphous even after post annealing treatment at 900℃, presenting good electrical performances including a dielectric constant of 12.7, an equivalent oxide thickness of 2 nm, a fixed charge density of 4× 1012 cm-2, and a leakage current density of 0.04 mA/cm2 at the gate bias of 2V. Post annealing treatment could reduce the leakage current and the fixed charge density effectively, but made the film surface rough and increased equivalent oxide thickness.