Control of selective epitaxial growth (SEG) in semiconductor manufacturing

Selective epitaxial growth (SEG) is one of the new process candidates to provide a solution for the production of high-performance devices at the sub-65 nm node when substantial integration problems encountered. However, there are challenges for monitoring this kind of new process. In this study, by applying suitable metrology, we can have good quantitative methods for selectivity and epitaxy quality monitor. Moreover, we can also observe the precise information of the incoming samples, which is critical to the epitaxial growth. First of all, we will describe the daily monitor method by SP1 for the SEG process. The high sensitivity of surface scattering responses to selective and non-selective conditions was proven. Quantitative measurement with timesaving using this new monitoring method is being proposed. Then, a method using F5x of KLA-Tencor has been developed to characterize the grown stack films before and after SEG in a production line. Experimental results show that not only can it provide the quality of grown epitaxial layer, but it can also provide the critical information of sample surface on which SEG will grow, which plays an essential role on epitaxial growth and determines if the SEG process is successful or not.