Single Cell Failures Caused by a Lateral Gate Effect

A single cell failure (SCF) is a common fail signature in dynamic random access memories (DRAMs). Generally write and read problems can be observed if a cell capacitor is not connected properly to its bitline. If the critical resistance of this connection exceeds a given threshold a failure might occur. In this analysis this threshold can be varied by a lateral gate effect of neighboring trenches. The first section gives a short introduction to the problem. An experimental analysis follows in the second section. Simulation results are presented in the third part and a short summary is given at the end.