PHOTORESIST

PURPOSE:To improve resistance to dry etching of a photoresist by incorporating a novolak resin, a diazide compd. and an azide polymer. CONSTITUTION:A cresol type novolak resin expressed by the figure, a diazide compd., and an azide polymer are incorporated into a photoresist. The azide groups in the azide polymer form chemically active nitrene groups by the photolysis when the photoresist after development is exposed to light having shorter wavelength than the light for exposure. A high molecular-forming reaction due to three dimensional crosslinking of the novolak resin with the azide polymer is caused by the reaction of said nitrene with neighboring molecules. By the method, the resistance of the photoresist to dry etching is improved because the photoresist is hardly vaporized even if lowering of mol. wt. of the photoresist is caused by the effect of plasma during dry etching.