The crystalline fraction of microcrystalline silicon films 18-200 nm thick,
deposited by VHF plasma and by chemical transport deposition (CTD) was cha
racterized by Raman and optical measurements. On a p-type CTD sample, thinn
er than 20 nm, a crystalline fraction as large as 78%, to our knowledge the
largest obtained by VHF plasma on p-type films in this thickness range, wa
s measured. Transmission electron microscopy shows crystallites extending t
o the interface with the substrate. Electrical conductivities in the range
10(-2)-10(0) S/cm, and 10(-1)-10(1) S/cm after annealing at 250 degreesC, w
ere measured. Weak dependence of crystalline fraction and electrical proper
ties on thickness was observed. (C) 2001 Elsevier Science B.V. All rights r
eserved.