Schottky barrier formation on electron beam deposited amorphous Si1minus;xGex@B:H alloys and amorphous (Si/Si1minus;xGex)@B:H modulated structures

摘要

Amorphous Si:H and Si1minus;xGex:H films were prepared by mixing electron beam evaporated silicon with a molecular beam of germanium from a Knudsen cell and with a beam of ionized hydrogen produced by a 0ndash;3 keV ion source. Aluminum Schottky barriers on two types of samples of (1) amorphous Si1minus;xGex:H with 0.15x0.85 and (2) modulated structures of 50times;100 Aring; layers of amorphous Si:H/ahyphen;Si0.8Ge0.2:H (10minus;5Torr PH hydrogen) were investigated. Barrier height was found to depend on the Ge concentration and possible Fermi level pinning due to the dangling bond deep level. The modulated structures showed a negative resistance region and a barrier height determined only by the composition of the first layer.