InP Processing Using an HBr High Density ICP Plasma

David Lishan, Unaxis USA
Jewon Lee, Dept. of Optical Engineering, Inje University
Grant Kim, Vitesse Semiconductor Corp.

This work explores using hydrogen bromide (HBr) to etch InP and InGaAs in a high density inductively coupled plasma system (ICP). Noncrystallographic etch rates of approximately 1100 Å/min with excellent surface morphology (RMS<2.5 nm) can be obtained using HBr at near room temperature with active substrate cooling. Similar etch rates can be observed at elevated etch temperatures (160ºC) that provide undercut profiles assisting self-aligned structures. The effects of ICP power, substrate bias, temperature, and pressure on etch rate, profiles, and surface morphology will be discussed in the context of device fabrication steps such as mesas and self-aligned structures.