High Field Electrical Conduction in Pre-Formed Al--ZnS--Al Thin Films in Metal--Insulator--Metal Devices

The high field electrical conduction mechanism for the widely used ZnS thin films in the microelectronic industry is investigated. Experimental data on the dc conduction as a function of the applied bias for the Al--ZnS--Al devices is carefully compared with the theoretical equations given by Schottky and Poole--Frenkel. The results yield the value of the coefficient of the barrier lowering ?compatible with the Schottky theory rather than the Poole--Frenkel theory, which are also in agreement with the results reported earlier by Maekawa Phys. Rev. Lett. 24 (1970) 1175