Method of reducing line-width variations in the production of photoresist patterns

摘要

The invention relates to a method of reducing line-width variations in the production of photoresist patterns on substrates intended for semiconductor integrated circuits by optical projection exposure. The photoresist layer is exposed in two steps using approximately a half dose each time. Between the exposures, the thickness of the photoresist layer is altered by a quarter of the wavelength lambda used for the exposure in the photoresist. The method is used in the production of VLSI semiconductor circuits.