The hydrogenated nanocrystalline silcon films (nc-Si:H) are deposited on silicon substrate byplasma enhanced chemical vapour deposition(PECVD) .The room temperature dark conductivity σof nc-Si: H is in the range of 10-3 -10-1Ω-cm1
higher than that of intrinsic silicon. Diodes consisting of nc-Si: H film are fabricated and their I-V curves show some quantum staircase below 77K. This novel physical features are explained qualitatively.