| abstract |
A one-time, voltage-programmable, logic element has an antifuse element constructed within a trench etched in a silicon substrate. A sidewall of the trench abuts a diffusion region. The trench is lined with a nitride dielectric layer, which is in turn covered by polycrystalline silicon. The polycrystalline silicon serves as a voltage reference line. In a preferred embodiment, the diffusion region forms a first source/drain region of a field-effect transistor. In order to program the element, a voltage sufficient to rupture the nitride dielectric layer is applied between the diffusion region and the reference line. The transistor is utilized to isolate a particular logic element from other logic elements. |