Effect of inert gas additive species on Cl high density plasma 2 etching of compound semiconductors Part II. InP, InSb, InGaP and InGaAs

The effects of the additive noble gases He, Ar and Xe on chlorine-based inductively coupled plasma etching of InP, InSb, InGaP and InGaAs were studied as a function of source power, chuck power and discharge composition. The etch rates of all materials with Cl2rHe and Cl2rXe are greater than with Cl2rAr. Etch rates in excess of 4.8 mmrmin for InP and InSb with Cl2rHe or Cl2rXe, 0.9 mmrmin for InGaP with Cl2rXe, and 3.8 mmrmin for InGaAs with Cl2rXe were obtained at 750 W ICP power, 250 W rf power, ;15% Cl2 and 5 mTorr. All three plasma chemistries produced smooth morphologies for the etched InGaP surfaces, while the etched surface of InP showed rough morphology under all conditions. q1999 Elsevier Science B.V. All rights reserved