Analysis of electrophysical characteristics of bistable MIS structures with samarium and cerium fluorides

Bistable MIS structures are promising for use in permanent memory devices, and are a convenient object for studying degradation phenomena under the influence of various external factors. This paper has studied the degradation of I-V and C-V characteristics of bistable germanium and silicon MIS structures with samarium and cerium fluoride under the influence of high electric fields and elevated temperatures. It has been found that empirical dependence of current density on voltage in high-ohmic state is described by degree dependence with index of degree 0,9–1,5. This indicator increases both with the increase in the number of electroforming cycles and with the increase in temperature. On n-type germanium substrates, a positive charge was observed at room temperature for all structures studied. On n- and p-type silicon substrates, the charge can be both positive and negative. Separate exposure to temperature results in an increase in positive charge with an increase in the number of cycles, for both germanium and silicon structures. The separate effect of the high electric field on the MIS structure with the n-type substrate also leads to an increase in the positive charge. However, the complex effects of high electric field and temperature lead to a trend of negative charge growth in the studied MIS structures.