High rate plasma etch processes for InP with smooth etched surfaces and highly anisotropic sidewall profiles were developed. ACH4:H2-based process using an electron cyclotron resonance (ECR) etcher and a reactive ion etcher (RIE) was investigated. Etch rates in excess of 120 nm/min in an ECR etcher usingCH4:H2:Arplasma and 135 nm/min in a RIE usingCH4:H2:O2were achieved in InP and produced minimal surface roughness. These etch rates are significantly faster than those previously reported.