How high is the adhesion strength of e-beam resists to different wafers?

Adhesion between substrate and coating is a sensitive feature of a resist, which is also true for e-beam resists.

PMMA-, copolymer and styrene acrylate resist are however significantly less prone for adhesion problems than e-beam resists of the AR 7000 product line, where smallest changes of the cleaning procedure or other parameters may have a fatal impact on the adhesion strength.

Silica, silicon nitride, and base metals (such as aluminium, copper) generally possess good resist adhesion features, while adhesion on SiO₂, glass, noble metals such as gold or silver, and on gallium arsenide is often insufficient. In this case, measures have to be taken to improve adhesion ( Question 3: Pre-treatment of substrates).

If the air humidity is too high (> 60 %), adhesion is substantially reduced.