Impact of Etching Depth on the Leakage Current of Recessed SiGe Junctions

Here, a systematic study is made of the leakage current in huge-area SiGe-Si p
⁺
-n junctions. As will be shown, both the perimeter and area leakage current density are a sensitive function of the S/D etch depth, whereby a higher leakage is obtained for deeper trenches. This can be explained by the presence of dislocations at the SiGe-Si interface, as revealed by transmission electron microscopy (TEM) and their relative distance to the electrical junction