Electronic behaviour and field emission of metal-semiconductor-insulator-metal (MSIM) heterostructures based on a-C:H films

In this paper, we report on electronic and field emission properties of metal-semiconductor-insulator-metal (MSIM) heterostructures employing semiconducting and insulating hydrogenated amorphous carbon (a-C:H) films. The a-C:H layers were deposited from plasma polymerisation of methane in a 20 kHz discharge. The current as a function of voltage (I-V) characteristic is consistent with Fowler-Nordheim (F-N) type tunnelling of carriers from semiconductor cathode into polymer-like a-C:H. The onset field for emission is about similar to6 V/mum. The transition barrier is found to be similar to0.05 eV, which is close to that obtained with a-C:H:N/Si heterojunctions. capacitance-voltage (C-V) measurements show negligible hysteresis and zero flat band voltage, and the interface states density, estimated from capacitance-frequency plot, is very low (N-SS similar to 4 x 10(10) cm(-2)). Heterostructures based on amorphous carbon films are perspective for the development of field emission displays (FEDs). (C) 2002 Elsevier Science B.V. All rights reserved.