High rate plasma etch processes for InP with smooth etched surfaces and highly anisotropic sidewall profiles were developed. A CH4:H-2-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 using CH4:H-2:Ar plasma and 135 nm/min in a RIE using CH4:H-2:O-2 were achieved in InP and produced minimal surface roughness. These etch rates are significantly faster than those previously reported.