INVESTIGATION ON ETCH CHARACTERISTICS OF GESBTE THIN FILMS FOR PHASE-CHANGE MEMORY

Abstract

ABSTRACT Inductively coupled plasma reactive ion etching of GeSbTe (GST) thin films with a photoresist mask was carried out in a Cl2/Ar gas. The monotonous increase in etch rate with increasing Cl2 concentration indicates that the etching of GST films obeys the reactive ion etching mechanism. The etch rates increased with increasing coil rf power and dc-bias voltage. The etch profiles was improved with decreasing coil rf power and dc-bias voltage and gas pressure gave little influence on the etch profile. The x-ray photoelectron spectroscopy analysis reveals that the rate limiting step in GST etching study is the etching of Te. Anisotropic etching of GST films was achieved using a Cl2/Ar chemistry at the optimized etch conditions.