O2/BCl3/Ar 플라즈마를 이용한 HfAlO3 박막의 식각특성 연구

Abstract

In this study, HfAlO3 thin films using gate insulator of MOSFET were etched in inductively coupled plasma. The etch characteristics of the HfAlO3 thin films has been investigated by varying O2/BCl3/Ar gas mixing ratio, a RF power, a DC bias voltage and a process pressure. As the O2concentration increases further, HfAlO3 was redeposited. As increasing RF power and DC bias voltage,etch rates of the HfAlO3 thin films increased. Whereas, as decreasing of the process pressure, etch rates of the HfAlO3 thin films increased. The chemical reaction on the surface of the etched the HfAlO3 thin films was investigated with X-ray photoelectron spectroscopy (XPS). These peaks moved a binding energy. This chemical shift indicates that there are chemical reactions between the HfAlO3 thin films and radicals and the resulting etch by-products remain on the surface.