Selective deposition of polycrystalline silicon thin films at low temperature by hot-wire chemical vapor deposition

Abstract

Polycrystalline silicon thin films have been selectively deposited at a substrate temperature of 300 °C on molybdenum or silicon over silicon dioxide, silicon nitride or Corning 7059 glass substrates in a continuous hot-wire chemical vapor deposition (HWCVD) process involving hydrogen and disilane. Excellent selectivity is achieved on features as small as 1 μm spaced molybdenum lines. The deposition rate on molybdenum is 60–100 Å/min which is higher than that obtained by a pulsed gas plasma-enhanced chemical vapor deposition (PECVD) or a very high-frequency PECVD (VHF-PECVD). The selective deposition rate obtained in our system is attributed to the high concentration of atomic hydrogen generated when molecular hydrogen passes over a heated tungsten filament.