Reactive ion etching of InP using CH sub 4/H sub 2 mixtures: Mechanisms of etching and anisotropy.

Reactive ion etching of InP with CH sub 4/H sub 2 mixtures, a promising process for optoelectronic device (e.g. semiconductor laser) fabrication, has been studied to understand the mechanisms of etching and anisotropy. Special attention has been paid to the polymer film that deposits on inert surfaces in the discharge; deposition rates have been used as a monitor of the discharge chemistry as well as for process orientation. Surface analysis shows that under etching conditions that maximize the InP etch rate while minimizing polymer deposition, the hydrocarbon coverage on the InP surface is no more than one or two monolayers, and the surface is significantly depleted of P.