1,2-naphthoquinone-2-diazidesulfonate ester photosensitive agent, method for producing the photosensitive agent, and photoresist composition

The invention provides a 1,2-naphthoquinone-2-diazidesulfonate ester photosensitive agent which is useful as a photosensitive agent employed in a photoresist for producing semiconductor integrated circuits, liquid crystal displays, EL displays, etc., a method for producing the photosensitive agent, and a photoresist composition containing the photosensitive agent. The 1,2-naphthoquinone-2-diazidesulfonate ester photosensitive agent is produced by reacting a polyhydric phenol with 1,2-naphthoquinone-2-diazidesulfonyl chloride in the presence of a neutralizing agent, wherein the polyhydric phenol is obtained by a condensation reaction between resorcinol and at least one aldehyde selected from C3-C10 aldehydes, and contains, as a predominant component, a compound represented by formula (I) and components exhibiting a retention time as measured by using GPC shorter than that of the compound represented by formula (I) in an amount of 10% or less, wherein each of R1, R2, R3, and R4 represents a C2-C9 alkyl group.