US Patent 7566932 Static random access memory unit

A static random access memory (SRAM) unit comprising a substrate, a gate dielectric layer, a gate, a trench capacitor, a pair of source/drain regions, a first contact and a second contact is provided. The substrate has a trench formed therein. The gate dielectric layer is disposed on the substrate and the gate is disposed on the gate dielectric layer. The trench capacitor is disposed in the trench near one side of the gate. The source/drain regions are disposed in the substrate near the respective sides of the gate with one of the source/drain region positioned between the gate and the trench capacitor. The first contact is electrically connected to the trench capacitor and the second contact is electrically connected to the other source/drain region.