Surface diagnostics of dry etched III-V semiconductor samples using focused ton beam and secondary ion mass spectrometry

In order to optimize the H-2/CH4 reactive ion etching process for InP, the surface composition of etched samples has been analyzed by means of a focus ed ion beam and secondary ion mass spectrometry. Harmful species of chlorin e and oxygen have been identified as causing surface roughness and etch-rat e fluctuations. polymer distribution on the masked surface and etched surfa ce phosphor abundance have been studied for various gas mixtures and rf pow er, establishing optimized CH4-rich etching conditions under which surface P content is closest to unetched material and polymer deposition is accepta ble. (C) 1999 American Vacuum Society. [S0734-211X(99)11406-9].