Controlled undercutting of v-groove channels in InP by photoresist etch mask.

A photoresist etch mask process has been developed for the etching of v-grooves in InP (001) for channeled substrate laser growth. The relationship between the photoresist (PR) mask undercutting and the dehydration bake temperatures, the post bake temperatures and the photoresist thickness were studied. The native oxide growth during the bake processes was believed to give the extra large undercut.