A carbon based bottom gate thin film transistor

This paper describes the fabrication and characterisation of a carbon based , bottom gate, thin film transistor (TFT). The active layer is formed from highly sp(2) bonded nitrogenated amorphous carbon (a-C:N) which is deposite d at room temperature using a filtered cathodic vacuum are technique. The T FT shows p-channel operation. The device exhibits a threshold voltage of 15 V and a held effect mobility of 10(-4) cm(2) V-1 s(-1). The Valence band t ail of a-C:N is observed to be much shallower than that of a-Si:H, but does not appear to severely impede the shift of the Fermi level. This may indic ate that a significant proportion of the a-C tail states can still contribu te to conduction. (C) 2000 Elsevier Science S.A. All rights reserved.