Suppression of stress induced drain leakage current of SOI MOSFETs by using partial trench isolation technology

In this report, stress analysis of the partial trench isolated (PTI) structure (Hirano et al, 1999) is performed as compared with a fully trench isolated (FTI) structure using process simulation. The PTI structure consists of the continuous remaining SOI layer under the trench oxide. It is found that the oxidation-induced stress of the PTI SOI MOSFETs during the trench isolation process can remain lower than that of the FTI SOI MOSFETs because oxidant diffusion to the SOI bottom surface is easily suppressed in the PTI SOI MOSFETs. Moreover, the high yield of the drain leakage current characteristics of the PTI SOI MOSFETs are shown.