Leakage in CMOS devices induced by pattern-dependent microloading effect

The difference of pattern density in photomask may cause different photo resist profile, and then etch rate or implant profile can be impacted. This is called the microloading effect. Some special topological structures in chip layout design may result in serious leakage in CMOS devices due to the microloading effect. In this case, the solution is often a mixture of design change and process optimization. A product with such potential risk structure is selected to study the leakage mechanism by microloading effect during lithography and implant process. The result indicates that photo resist profile is impacted dramatically due to the microloading effect, which results in doping agent injecting in wrong area during implant process. Lithography process window is affected as well. Finally solution is presented for the leakage induced by microloading effect.