Low damage InP sidewall formation by reactive ion etching

We investigated the sidewall damage formed by electron-cyclotron-resonance reactive ion etching (ECR-RIE) using CH/sub 4//H/sub 2/. It was found that the reverse current of p-i-n junctions is affected by the O/sub 2/ plasma treatment conditions for removing the hydrocarbon deposited on the etching mask during etching. By optimizing the treatment conditions, we succeeded in low damage sidewall formation, which is of the same quality as the mesa formed by wet etching. AES measurements indicate that the thickness of the damaged region is restricted to about 8 nm.