EFFECT OF LOW-TEMPERATURE ANNEALING ON THE SURFACE-STATE OF A-SI-H FILMS

The current transport in metal/a-Si:H contacts was largely affected by low temperature annealing of a-Si:H in high vacuum prior to the formation of metal contacts. This effect was considered to originate from the decrease of the density of surface states in the a-Si: H surface under the low temperature annealing process. A primitive experiment was applied for confirmation of the existence of surface states in a-Si : H films, by measurement of current-voltage (J-V) characteristics of the a-Si:H/a-Si:H contact diode in which two a-Si: H surfaces were contacted face-to-face. The difference between the J-V characteristic of the a-Si:H/a-Si:H contact diode composed of a-Si:H films as deposited and that of the a-Si:H films annealed at low temperature verified that the density of surface states of the a-Si: H film remarkably decreases by low temperature annealing.