Application of Penning discharge to the deposition of amorphous silicon

Abstract

Hydrogenated amorphous silicon films (a-Si:H) have been successfully prepared by a Penning glow discharge of silane, in which both the electric and magnetic fields are applied. A stable discharge has been observed between electrodes in a wide pressure range (0.005–0.5 Torr). It was found that the plasma was nearly confined between electrodes, thus reducing the quartz tube-plasma interaction. Optical and electrical properties have been studied in correlation with SiH4/SiH4+H2 ratio. The photoconductivity of the a-Si:H films show highest value when the ratio is 0.2. The photoconductivity of the a-Si:H films deposited at 0.07 Torr is as high as 5.2×10−4 (Ω cm)−1 under simulated AM 1 (100 mW/cm2) and the corresponding normalized photoconductivity ημτ is 4.6×10−5 cm2/V under 1.9-eV illumination (3×1014 photons/ sec cm2). The films predominantly show the absorption peak due to Si:H stretch mode at 2000 cm−1. The potential features of this technique over conventional ones are described.

Patterning of hydrogenated microcrystalline silicon growth by magnetic field

“…Magnetized plasmas are commonly used in magnetron or electron cyclotron resonance deposition systems 11,12 and in early research of silicon films magnetization of silane plasmas was also explored. [13][14][15][16] The magnetic field was found to enhance the deposition rate 13 and to change plasma chemistry. 14 It was also used to control the effects of ion bombardment 15 and radicals 16 or to limit the silane powder formation.…”