Fundamental consideration for CDM (Charged Device Model) breakdown was investigated with 90nm technology products and others. According to the result of failure analysis, it was found that gate oxide breakdown was critical failure mode for CDM test. High speed triggered protection device such as ggNMOS and SCR (Thyristor) is effective method to improve its CDM breakdown voltage and an improvement for evaluated products were confirmed. Technological progress which is consisted of down-scaling of protection device size and huge number of IC pins of high function package makes technology vulnerable and causes significant CDM stress. Therefore, it is expected that CDM protection designing tends to become quite difficult. In order to solve these problems in the product, fundamental evaluations were performed. Those are a measurement of discharge parameter and stress time dependence of CDM breakdown voltage. Peak intensity and rise time of discharge current as critical parameters are well correlated their package capacitance. Increasing stress time causes breakdown voltage decreasing. This mechanism is similar to that of TDDB for gate oxide breakdown. Results from experiences and considerations for future CDM reliable designing are explained in this report.

An effective procedure to determine the Burn-In acceleration factors for 130nm and 90 nm processes are discussed in this paper. The relationship among yield, defect density, and reliability, is well known and well documented for defect mechanisms. In particular, it is important to determine the suitable acceleration factors for temperature and voltage to estimate the exact Burn- In conditions needed to screen these defects. The approach in this paper is found to be useful for recent Cu-processes which are difficult to control from a defectivity standpoint. Performing an evaluation with test vehicles of 130nm and 90nm technology, the following acceleration factors were obtained, Ea>0.9ev and β (Beta)>-5.85. In addition, it was determined that a lower defect density gave a lower Weibull shape parameter. As a result of failure analysis, it is found that the main failures in these technologies were caused by particles, and their Weibull shape parameter “m” was changed depending of the related defect density. These factors can be applied for an immature time period where the process and products have failure mechanisms dominated by defects. Thus, an effective Burn-In is possible with classification from the standpoint of defect density, even from a period of technology immaturity.