Highly-doped narrow bandgap materials, which may be nearly metallic at room temperature, may behave as semiconductor materials with high-mobility carriers when the carriers are cooled to a low temperature, e.g., below 250 Kelvin. In such low temperature environments, materials with narrower bandgaps may be used to form tunnel diodes. For example, one or both of the n-doped and p-doped regions may include a material with a bandgap of less than 0.5 eV. The materials used may have a high number of carriers, leading to relatively high currents, and better performance compared to previous room-temperature tunnel diodes using silicon or other standard semiconductor materials. For example, materials for forming tunnel diodes for operation at low temperature may be degenerately doped, with dopant concentrations of at least 10.sup.18 cm.sup.3 or 10.sup.19 cm.sup.3.

A negative differential resistance (NDR) device, such as Gunn diode or a tunnel diode, is included in an integrated circuit device to regulate voltage delivered to circuitry on the device, such as a logic circuit or memory circuit. The NDR device may be biased at a knee voltage to provide a stable supply voltage to the IC device. The NDR device may be implemented in a metallization layer of the integrated circuit device.

A negative differential resistance (NDR) device, such as Gunn diode or a tunnel diode, is included in an integrated circuit device to regulate voltage delivered to circuitry on the device, such as a logic circuit or memory circuit. The NDR device may be biased at a knee voltage to provide a stable supply voltage to the IC device. The NDR device may be implemented in a metallization layer of the integrated circuit device.