P-I-N diodes on high deposition rate thick a-Si : H layers from pure SiH4

During the last years, much interest has been dedicated to the use of P-I-N hydrogenated amorphous silicon-based diodes as radiation detectors, for hi gh energy experiments as well as for medical applications. Although indirec t detection is provided with P-I-N diodes several microns thick in conjunct ion with scintillate layers that transform the radiation into photons, in o rder to provide a direct detection thicker P-IN diodes (> 50 mu m) are requ ired. These thick layers have been obtained from glow discharge, with param eters and gas mixtures that provide high deposition rates. This work presen ts results on deposition rates of a-Si:H layers obtained from pure SiH4 in a plasma enhanced chemical vapor deposition (PECVD) equipment with parallel plates of equal area, at temperatures between 200 and 350 degrees C, press ure between 2.6 and 60 Pa and a power density of 50 mW/cm(2). Deposition ra tes of up to 2.5 mu m/h were obtained. P-I-N diodes up to 18 mu m thick, fa bricated on these films using photolithographic processes, are characterize d. (C) 1999 Elsevier Science S.A. All rights reserved.