Microloading effect is one of the challenging phenomena in sub-halfmicron aluminum etching, which represents the decreasing etch rate with shrinking pattern size and open area. Process parameters should be optimized to control etch rate difference in different feature sizes. In this experiment, it is found that pressure and BC1a/C12 gas flow ratio are two major factors to affect on etch rate niicroloading. Under the standard BC1ilC12 chemistry, optimizing process parameters is not enough to reduce microloading sufficiently. Therefore, additional gas is introduced to suppress microloading effect less than 10%. N2 or CUP3 gas addition is not effective to improve microloading effect through polymerization mechanism. It is observed that CF4 gas addition is the most successful to minimize microloading effect by enhancing ion assisted chemical reaction in small feature size.

This paper describes the intra-field registration error caused by the mix of exposure illumination and isolation process independently. Modified illuminations such as annular, quadrupole, and small sigma aperture for phase shift mask are widely used to extend the feasible limits in the current optical process application. Meanwhile, each of illumination conditions may cause the deterioration of the intra-field registration since they have different optical properties. Also isolation process in CMOS has been considered as a critical step causing the intra-field registration error induced by the wafer stress from the thermal cycle and the different type of films. The mix of illumination conditions, isolation schemes, the temperature and thickness of field oxidation were split to investigate their effects. And the compensation of intra-field registration error was performed by shot scale value.

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