USE OF A NEW-TYPE OF ATOMIC-HYDROGEN SOURCE FOR CLEANING AND HYDROGENATION OF COMPOUND SEMICONDUCTIVE MATERIALS

This article describes a source of atomic hydrogen (AH) based on a ref lected Penning are discharge with a hollow cathode and a self-heating electrode, designed for treating semiconductor materials with atomic h ydrogen in technological processes. The source can readily be incorpor ated in industrial systems for thin-film deposition, ion implantation, and molecular beam epitaxy. In experiments on treatment of semiconduc tor structures the source was operated at a discharge operating voltag e of 200 V and a current of 2 A. Measurements of the activation energy of AH etching have been preformed for GaAs (0.13 eV) and InP (0.19 eV ) anode oxides and for a SiO2 film produced by chemical vapor depositi on method (0.15 eV). The thickness of the native oxide layer has been investigated as a function of temperature and treatment time. The oxid e film was completely removed in 1-2 min at a specimen temperature of T = 400 degrees C and in 3-5 min at T = 350 degrees C. It has been sho wn that when the AH cleaning of the GaAs surface and deposition of a m etal film (AuGe, Ti, Ni) are accomplished in a unified vacuum cycle, n o contaminant is present at the film-substrate interface. This, in par ticular, improves the characteristics of structures with a Schottky ba rrier. It has been found experimentally that the AH treatment of the G aAs surface reduces the rate of the subsequent oxidation of the surfac e in air. The AH source was also used for hydrogenation of the near-su rface layers of semiconductor structures. The devices manufactured fro m the hydrogenized structures showed improved performance. (C) 1998 Am erican Vacuum Society. [S0734-2101(98)09704-8].