| dc.description.abstract | The photolithography process is one of the most critical technologies in semiconductor manufacturing technology, the photolithography process mainly includes three steps: coating photoresist, exposure, and development. In recent years, due to the rising awareness of environmental protection and carbon reduction and the cost control of enterprises, reducing the amount of photoresist is becoming one of the emphases of various semiconductor companies and related technology industries. This research is mainly aimed at the spin coating part of the photolithography process. The amount of positive photoresist used in the experiment was reduced, and by improving the adjustment of the experimental parameters of the spin coating process, a better combination of process parameters was sought, and the results of the optimized parameters are verified to meet the current specifications and mass production conditions.
In this experiment, a 12-inch double polished silicon wafer is selected, and the optimization of positive photoresist reduction was the goal. We study the influence to the difference between film thickness mean value, film thickness range value, and the quality of photoresist coverage on the wafer surface during the process of reducing the positive photoresist. The conducted factors used in the spin coating process includes the variation of spin coating module, RRC (Reduced Resist Consumption) pre-wetting speed, spin-up speed and spin-off speed, we also study and analyze the feasibility of mass production. The experimental results show that when the positive photoresist is reduced and the spin-up speed is changed, the film thickness mean value remains unchanged, but the film thickness range value gradually become worse. Furthermore, by conducting the configuration changes of the RRC pre-wetting speed and spin-up speed, the worsening phenomenon of the film thickness range value during the process of positive photoresist reduction has been improved. The study demonstrates the optimization result of the positive photoresist weight reduction, through the optimization of the spin coating process, the original positive photoresist usage can be reduced from 0.9g to 0.6g. Moreover, through the analysis result of the positive photoresist weight reduction spin coating stability and product verification test items, it shows no difference of the stability and test results before and after the positive photoresist reduction. It is expected to reduce the cost of photoresist by about 33.3%.
The results and conclusions obtain in this experimental study are intended to establish a set of fast and effective models and methods to further shorten the time to adjust photoresist coating manufacturing parameter while evaluating different types of photoresist with different viscosity coefficients in the application of the photolithography process. This method can help to target on the manufacturing parameter good for mass production and optimize the overall production efficiency. Moreover, it is expected that this method can be contributed to the semiconductor and related technology industries as a reference in the field of photoresist coating process. | en_US |