Abstract
Shallow trench isolation induced mechanical stress has become more and more important as the dimension of devices scaling-down continuously. The stress can induce the variation of device’s performance as large as 20% depend on processes and layout of devices. Up to now, the layout dependence of the STI mechanical stress effect has not been understood clearly. In this thesis, we have proposed an exponential stress distribution model successfully explaining most of the behaviors of the layout dependent STI-induced mechanical stress effect.Temperature dependence of STI mechanical stress effect has been studied thoroughly for the first time in this thesis. According to the results, increased operating temperature results in a slight reduction of the drive-current degradation caused by STI-induced mechanical stress for n-MOSFET. An empirical formula was obtained and can be taken into account in IC design easily.In order to overcome STI-induced mechanical stress effect, we have proposed a new method to improve the stress effect by changing the structure of n-MOSFET without any modification of processes. It has been proved that the new structured devices are less sensitive to STI-induced mechanical stress effect than conventionally structured devices due to the stress reduction in newly structured devices.In the noise point of view, we have shown that noise characteristics are insensitive to STI-induced mechanical stress.