Characterization of tunneling current in ultra-thin gate oxide

Experimental measurements and physical modeling of the tunneling current th rough ultra-thin gate oxides (1-6 nm) are presented for a large variety of experimental conditions including injection of electrons and holes from bot h accumulation and inversion layers and different cathode/anode polarities. By comparing experiments and simulations, the following issues are address ed. (i) importance of different components of the tunneling current; (ii) i mpact of quantization effects; (iii) sensitivity to the device structural p arameters (doping levels, oxide thickness, etc.); (iv) impact of different stress conditions during aging experiments. The results of this study indic ate the importance of quantum mechanical modeling and the presence of many tunneling mechanisms in ultra-thin oxide MOS devices, and that I-V measurem ents may be used for. oxide characterization at thickness levels where othe r techniques (C-V) become inaccurate. (C) 2000 Elsevier Science Ltd. All ri ghts reserved.