Process for forming an amorphous silicon film

Claim 1

A process for forming an amorphous silicon film, comprising the steps of: heating and vaporizing silicon in a closed type crucible with at least one injection nozzle to form vapor of silicon; ejecting the vapor of silicon through the injection nozzle into an ionization chamber to expand adiabatically the vapor of silicon so as to attain a supercooled state and form clusters comprising atoms of the vapor of silicon; ionizing at least one atom forming the clusters by bombarding the clusters with electrons in said ionization chamber to produce ionized clusters; introducing hydrogen molecules at a pressure of about 10 -3 Torr or less into said ionization chamber and concurrent to ionizing of said vapor of silicon ionizing at least some said introduced hydrogen molecules; and simultaneously ejecting the ionized clusters and ionized hydrogen from said ionization chamber to collide with a substrate with kinetic energy imparted to the clusters at the time of the ejection from the nozzle thereby forming an amorphous silicon film deposited thereon.