Chemically induced CD shrink techniques based on sidewall formation

1 Chemically induced CD shrink techniques based on sidewall formation 

As the name implies, this technique increases the thickness of the sidewall, resulting in a decrease in the diameter of the hole or trench opening. It is used in reducing the CD of contact hole and trench features. The resolution enhancement of lithography assisted by chemical shrink (RELACS) is a good example of this technique. 

1 Resolution enhancement of lithography assisted by chemical shrink (RELACS) 

Toyoshima, T. Ishibashi, N. Yasuda, S. Tarutani, T. Kanda, K. Takahashi, Y. Takano, and H. Tanaka, Below 100 nm hole pattern formation using resolution enhancement lithography assisted by chemical shrink (RELACS), J. Photopolym. Set Technol. 15(3), 377 378 (2002). 

The RELACS technique offers many advantages over a thermal shrink approach. For example, it reduces iso-dense bias when compared to thermal shrink techniques, has very low pitch dependence, reduces LER and line width roughness (LWR), and improves etch resistance. 

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