Resolution enhancement of lithography assisted by chemical shrink

RELACS resolution enhancement of lithography assisted by chemical shrink... 

The postexposure-based techniques are grouped into three broad categories, namely, reflow-based. shrink techniques, chemical-based shrink techniques, and plasma-assisted shrink techniques. The reflow-based shrink techniques comprise thermally induced reflow and electron-beam heating-induced reflow of patterned resist features. The chemical-based shrink techniques comprise those techniques that either increase or decrease the sidewall thickness of already patterned resist features, thus effectively altering their critical dimension. Examples of chemical-based shrink techniques that result in an increase in the sidewall of the patterned features include techniques based on RELACS (resolution enhancement of lithography assisted by chemical shrink) and CARL (chemical amplification of resist lines).Examples of chemical-base shrink techniques that result in decrease... 

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. 

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