Direct non-ohmic switch for voltage instability protection and methods for forming the same

A device structure comprising:

• semiconductor devices located on a substrate;
• metal interconnect structures located in dielectric material layers overlying the semiconductor devices, wherein the metal interconnect structures include device contact via structures, conductive line structures at multiple levels, and conductive via structures providing vertical electrical connections;
• an electrostatic discharge line overlying the dielectric material layers and configured to carry transient current during electrostatic discharge events;
• a non-Ohmic switching material portion providing non-Ohmic current-voltage characteristics and comprising an ovonic threshold material or a phase change memory material;
• a first switch electrode electrically connected to one of the semiconductor devices through a subset of the metal interconnect structures and contacting a sidewall and a top surface segment of the non-Ohmic switching material portion;
• and
• a second switch electrode electrically connected to the electrostatic discharge line and contacting another sidewall and another top surface segment of the non-Ohmic switching material portion.

A method of forming a device structure comprising:

• forming semiconductor devices on a substrate, wherein each semiconductor device includes source electrodes, drain electrodes, semiconductor channels, and gate structures;
• depositing dielectric material layers overlying the semiconductor devices;
• patterning and depositing metal interconnect structures embedded in the dielectric material layers, wherein the metal interconnect structures provide electrical connections to the semiconductor devices;
• etching a via cavity in one of the dielectric material layers to expose sidewalls and a recessed bottom surface;
• depositing a non-Ohmic switching material in the via cavity to form a non-Ohmic switching material portion providing non-Ohmic current-voltage characteristics;
• depositing and patterning a first switch electrode contacting a sidewall and a top surface segment of the non-Ohmic switching material portion;
• and
• depositing and patterning a second switch electrode contacting another sidewall and another top surface segment of the non-Ohmic switching material portion.