Influence of process-induced stress on device characteristics and its impact on scaled device performance

This paper reports on the effects of oxidation-induced stress on the genera tion current in pn-junction and gated diodes. It is observed that even in t he regime where no extended defects are present, the generation current is a strong function of the compressive stress in the substrate. Experimental results are presented revealing an order of magnitude increase in generatio n current for stress changes of a few 100 MPa's, A stress-induced bandgap n arrowing model that describes the relationship between the oxidation-induce d stress and the generation current in MOS devices is proposed and experime ntally verified. Using this model, we have calculated the stress-induced ge neration current in scaled shallow trench isolated (STI) devices due to reo xidation after STI formation. As the device pitch is reduced a large increa se in stress and leakage current is observed, consistent with the experimen tal data.