Low-Temperature Deposition of Microcrystalline Silicon by Microwave Plasma-Enhanced Sputtering

P. Müller¹, W.M. Holber², W. Henrion¹, E. Nebauer³, V. Schlosser⁴, B. Selle¹, I. Sieber¹, W. Fuhs¹

1. Hahn-Meitner-lnstitut, Rudower Chaussee 5, DE-12489 Berlin, Germany

2. Applied Science and Technology, Inc., 35 Cabot Road, Woburn MA 01801, USA

3. Ferdinand-Braun-lnstitut für Höchstfrequenztechnik, Rudower Chaussee 5, DE-12489 Berlin, Germany

4. Institut für Materialphysik, Universität Wien, Strudlhofgasse 4, AT-1090 Wien, Austria

Keywords: Electron Cyclotron Resonance Plasma, Sputtering, Silicon

Abstract. The technique of microwave plasma-enhanced sputtering has been applied to the deposition of silicon onto glass (Corning 7740 and 1737), silica and Si substrates. With this technique, unlike typical magnetron sputtering, the target material is sputtered into a dense electron cyclotron resonance plasma which causes ionization and activation of the majority of the species leading to layer growth. The Si films were deposited with a rate of typically 10 nm/min at substrate temperatures between 350-450 °C. Ar or mixtures of Ar and H₂ served as sputter gas. Film inspection by scanning electron microscopy, measurement of the optical reflectance and transmittance (0.5-6 eV), Raman scattering, and thin film x-ray diffraction confirmed the crystalline modification of the layers with an average crystallite size of 20-30 nm. Moreover the Si layers have been characterized by secondary ion mass spectroscopy, Rutherford backscattering spectrometry, electron spin resonance, and measurements of the dark conductivity and the Hall effect.