Modification of Development Parameters of 193 nm Chemically Amplified Resist with Pattern Density

摘要

It is necessary to have more appropriate resist parameters for a lithography simulator to predict the real photoresist profile. Especially, the development parameters can be crucial to mimic the real process. It has been reported that the development parameters of photoresist with or without underlying patterns are different. Since pattern density could affect the development parameters of the photoresist, the development parameters need to be modified for better simulation. We studied the changes of development parameters due to pattern density underlying photoresist and compared the simulated resist profiles with SEM microphotographs. First, we obtained the development parameters by flood exposure experiment and applied them to our lithography simulator LUV. The simulated resist profile was then compared to SEM microphotograph. Second, we tried to modify the development parameters for the simulated resist profile to match SEM photograph. The development parameters should be modified according to the pattern density for more accurate lithography simulation. We also determined the relationship between the changes of the parameters and the pattern density. To investigate the effect of the modification we analyzed the line width differences before and after the modification.