Abstract: Thin film electrical structures, such as threshold switching devices and phase change memory cells, preferably utilizing electrically stable, relatively inert, conductive electrodes including a non-single-crystal deposited film of carbon material, are disclosed. The film of carbon material, which preferably is amorphous and substantially pure, is disposed adjacent to a layer of active material such as an amorphous semiconductor, and serves to prevent undesired degradation of the active material, especially when the device is carrying appreciable current in its on-state. A method of making such structures with high quality interfaces between the semiconductor layer and the conductive carbon barrier layers adjacent thereto by successively depositing such layers in a continuously maintained partial vacuum is disclosed. The method may include a step performed in the vacuum for hermetically sealing all of, or at least the electrically switchable portion of, the active layer against subsequent contamination.

Abstract: Solid-state overvoltage protection devices, preferably formed of deposited thin film, chalcogenide, threshold switching materials, typically include at least one elongated current conduction path through an elongated cross-sectional area of the threshold switching material. The cross-sectional area is formed with a length far exceeding the effective width thereof for distributing the transient current produced by overvoltage conditions over a relatively large area. In this manner, the concentration of localized heating effects can be avoided.

Abstract: There is disclosed a thin film photoprogrammable memory array with a substantially increased resistance associated with each cell of the array. First and second sets of orthogonally oriented address lines are formed on a substrate with the first set of address lines crossing the second set of address lines at insulated cross-overs. A plurality of amorphous silicon diodes are deposited on the members of the first set of address lines adjacent the insulated cross over points. Settable memory material, an optically programmable chalcogenide, is deposited in electrical contact with each of the amorphous silicon diodes and in electrical contact with a member of the second set of address lines adjacent the cross-over region. When the settable memory material has been set to its high conductivity state, the electrical resistance between the amorphous silicon diode and the adjacent member of the second set of address lines is proportional to an effective electrical length measured along the settable storage member.