An XPS Study of the Plasma Etching of Aluminum with CCl₄

Abstract

X-ray photoelectron spectroscopy (XPS) has been employed to study the plasma etching of oxidized aluminum with CCl₄. The data indicate that the plasma etching of Al/Al₂O₃ with CCl₄. produces a complex chlorocarbon polymer. Further, during the etching process, AlCl₃ is imbedded in the substrate. Post-etching with CF₄ to remove the imbedded material does not remove all of the AlCl₃. The remaining AlCl₃ can react with water to form HCl and, therefore, initiate corrosion of the aluminum. However, the water adsorption/desorption characteristics of unetched and etched Al/Al₂O₃ are essentially identical.

Key Words:

• X-ray photoelectron spectroscopy
• plasma etching
• aluminum