Hybrid electron cyclotron resonance-RF plasma etching of TiNxthin films grown by low pressure rapid thermal metalorganic chemical vapour deposition

The use of F-based (SF 6 /O 2 , CF 4 /O 2 and CHF 3 /O 2 ) electron cyclotron resonance discharges for dry etching of TiN x films deposited onto InP by low pressure (3-10 Torr), rapid thermal metalorganic chemical vapour deposition is described. Etch rates of 50-100 AA min -1 are obtained for low DC biasing (-100 V) of the sample, giving rise to anisotropic features, infinite selectivity of etching TiN x over InP, and minimal damage to the semiconductor. SF 6 /O 2 mixtures offer the fastest etch rates, while CHF 3 /O 2 discharges produce significant polymer deposition under high pressure (20 mTorr) or high microwave power (>200 W) etching conditions.