Long Electron Cyclotron Resonance Plasma Source for Reactive Sputtering

Abstract

A long electron cyclotron resonance (ECR) plasma source using slot antennas and permanent magnets was developed for large-area plasma processing. Microwaves were radiated from the slot antennas on a 30-cm-long rectangular waveguide and efficiently absorbed to plasma by ECR magnetic fields of permanent magnets. The plasma source operated above 0.014 Pa for Ar at 437 W. The maximum plasma density was 1.77 ×1017 m-3 at 437 W for 0.078 Pa. The spatial plasma uniformity was ±8.2% within 200 mm length at 437 W for 0.078 Pa. The plasma source was experimentally applied to reactive sputter deposition of TiN film using a mixture of Ar and N2. Titanium nitride film was successfully deposited with ±14.1% spatial uniformity within 160 mm length. From X-ray photoelectron spectroscopic analysis, Ti–N bonds were newly created and the atomic composition ratio was nearly equal to the stoichiometric value of TiN at a N2/Ar mass flow rate of 1.5.