Abstract
The effect of the ortho-bonding unit which has been regarded as an important structural factor in novolak on the positive photoresist, was studied from the standpoint of the alkaline dissolution behavior of photoresists. A low molecular weight compound (6P) which was expected to turn itself into the ortho-bonding unit in novolak was synthesized, and this was introduced into the novolak. Consequently, the resist containing this novolak was shown to have remarkable effects on the dissolution inhibition (unexposed part) and the dissolution promotion (exposed part) compared with resists containing conventional novolak. These effects resulted in the increase of the dissolution contrast and the improvement of the pattern profile. Thus, the effect of the ortho-bonding unit was clarified, and it was confirmed that this low molecular weight compound 6P is useful for the introduction to the higher molecular weight component of the novolak to make the ortho-bonding unit.
