Enhancement of CMP pad lifetime for shallow trench isolation process using profile simulation

In the present work, the role of disk sweep condition in a pad profile has been investigated with the help of pad conditioning simulation with parameters proposed on the basis of the Preston polishing model, in order to enhance the lifetime of the polymer pad material for shallow trench isolation (STI)-chemical mechanical polishing (CMP). From the comparison of the degree of mechanical wear experimentally measured with those numerically simulated as a function of sweep rate, the pad profile has been optimized. Furthermore, the application of the results to STI process for 0.18 μm DRAM memory showed a significant extension of pad lifetime.