Impact of STI stress on 40-nm dogbone layout N-MOSFETs

Based on the test structures and silicon measurement data done at 40nm technology, we analyze the impact of varying length between the contacted active-area and gate (S) on the performance of NMOS dogbone devices, such as saturation drain current (Idsat), threshold voltage (Vth), and leakage current (Ioff). The experiments show that as the length between the contacted active area and gate (S) is increased from 0.07um to 5.02um, both Idsat and Ioff reach the maximum at 0.62um and then gradually decrease, while Vth has a 19.7% monotonic decrease.