Patent ID: 6579802
Filing Date: 2003-06-17
Classification: H01L

Abstract:
A process for etching a feature having a sidewall and a floor in an InP-based semiconductor sample using an ICP RIE system having a first RF generator to control a plasma density of a plasma, a second RF generator to control ion energies of the plasma, and a platen for supporting the InP-based semiconductor sample inside a chamber of the ICP RIE system and within which said process is carried-out, said process comprising the steps of:(a) placing the sample on the platen; (b) heating the platen to a temperature of between approximately 130Â° and 400Â° C.; (c) introducing reactive source gases into the chamber, said reactive source gases having a hydrogen part and a chlorine part at a volumetric flow rate ratio of said hydrogen part and said chlorine part of greater than 1:1; (d) providing a pressure within the chamber of less than approximately 5 mT; (e) setting the power of the first RF generator to between approximately 200 and 700 watts to generate a plasma discharge and provide a relatively low flux of incident ions in the plasma; (f) setting the power of the second RF generator to between approximately 80 and 200 watts to create an electric field across the plasma and control the bias through which plasma ions are accelerated; (g) etching the feature in the InP-based sample by bombardment with accelerated plasma ions at an etch rate of between approximately 0.38 and 1 &mgr;m per minute, the sidewall of the etched feature having a root-mean-square roughness of less than approximately 5 nm.