In this paper, we present the results on deposition rates and characterization of a-Si:H layers deposited from pure SIR, in 13.56-MHz plasma enhanced chemical vapor deposition (PECVD) equipment, where the use of parallel plates of equal area, long gas residence as well as the optimization of process parameters doubled the previously reported deposition rates for this r.f. frequency and gas. A deposition process using a 10% dilution of SiH4 in H-2 was also optimized to increase the deposition rate to 1.5 mum/h. I-V and I-T curves of PIN diodes up to 18 mum thick fabricated on these high deposition rate a-Si:H layers were characterized. The density of ionized states at deep depletion were determined and compared with those obtained for diodes fabricated with other standard and high deposition rate methods.