The present application provides planar and stacked resistor structures that are embedded within an interconnect dielectric material in which the resistivity of an electrical conducting resistive material or electrical conducting resistive materials of the resistor structure can be tuned to a desired resistivity during the manufacturing of the resistor structure. Notably, a doped metallic insulator layer is formed atop a substrate. A controlled surface treatment process is then performed to an upper portion of the doped metallic insulator layer to convert the upper portion of the doped metallic insulator layer into an electrical conducting resistive material layer. The remaining doped metallic insulator layer and the electrical conducting resistive material layer are then patterned to provide the resistor structure.

A thermally protected metal oxide varistor includes a body, a first electrode, a thermal fuse, and a glue. The body is made up of a crystalline microstructure including zinc oxide mixed with one or more other metal oxides. The first electrode is located on one side of the body and is connected to a first lead wire. The thermal fuse is connected between the first electrode and the first lead wire. The glue is to be deposited over the thermal fuse as well as over a top portion of the first lead wire.

A resistor material including a plurality of crystalline phases having a positive temperature coefficient of resistance, and an amorphous phase having a negative temperature coefficient of resistance and having a resistivity higher than the crystalline phase, in a mixed state, is provided. Moreover, a resistor element having a resistor film configured by the resistor material described above, and a method of manufacturing a resistor element by forming a film of an amorphous material having a negative temperature coefficient of resistance and subjecting this film to an annealing treatment to obtain the resistor element described above, are provided.