A deep trench isolation for silicon

A novel deep trench isolation for silicon is described. The materials used in the study are /spl Phi/100, p-type, <100>, 7-12 /spl Omega/-cm silicon wafers. It has been observed from the SEM micrograph that the width of silicon trench is 2 /spl mu/m, and that the depth of silicon trench is 6.5 /spl mu/m. There is almost no poly-silicon void in the trenches. The height of surface steps is less than 50 nm. Also a trench breakdown voltage of 35 V has been obtained. The leakage current for the isolation is less than 3 nA/35 V.