Abstract: Provided is a novel sulfonium salt that has high solubility in a solvent and has high light sensitivity to, especially, light having a wavelength not longer than deep-UV (254 nm) and a novel photo-acid generator comprising the sulfonium salt. The invention relates to a sulfonium salt represented by the following general formula (1) and a novel photo-acid generator comprising the sulfonium salt. wherein R1 represents an electron withdrawing group; R2 and R3 each independently represent an alkyl group having 1 to 5 carbon atoms, an alkoxy group, an acyl group, a halogenated alkyl group, a halogen atom, a hydroxyl group, a cyano group, or a nitro group; p and q each independently represent an integer of 0 to 5; and X?represents a monovalent counter anion.

Abstract: A slit nozzle which is easily manufactured and in which no capillary action occurs, and an apparatus for supplying a treatment liquid using the slit nozzle are disclosed. The slit nozzle is constructed of a left portion and a right portion joined to each other, one of which is made of metal and the other of which is made of resin. In the apparatus for supplying a treatment liquid using one or more of the slit nozzles, the slit nozzles are provided in a circulating passage of a treatment liquid whose temperature is controlled.

Abstract: A novolak resin precursor is composed of bonded phenolic moieties, one of the hydrogen atoms in the o- or p-positions relative to the hydroxy group of each phenolic moiety is substituted with an alkyl or alkenyl group having 1 to 3 carbon atoms, and the other two hydrogen atoms are bonded through methylene bonds. The content of ortho—ortho bonding is 30 to 70% relative to the number of total methylene bonds and the weight average molecular weight of the precursor is 300 to 10,000. A novolak resin is obtained from this precursor, and a positive photoresist composition comprises this novolak resin. The invention provides a positive photoresist composition that comprises less binuclear compounds, suppresses scum formation, is excellent in terms of definition and coating performance and provides a resist pattern having satisfactory heat resistance.

Abstract: Proposed is a novel undercoating composition to form an undercoating layer interposed between the surface of a substrate and a photoresist layer with an object to decrease the adverse influences by the reflection of light on the substrate surface in the pattern-wise exposure of the photoresist layer to ultraviolet light without the undesirable phenomena of intermixing between layers and notching along with a large selectivity ratio in the etching rates between the patterned resist layer and the undercoating layer in a dry-etching treatment. The undercoating composition comprises (A) an ultraviolet absorber which is a benzophenone compound or an aromatic azomethine compound each having at least one unsubstituted or alkyl-substituted amino group on the aryl groups and (B) a crosslinking agent which is preferably a melamine compound having at least two methylol groups or alkoxymethyl groups bonded to the nitrogen atoms in a molecule in a weight proportion (A):(B) in the range from 1:1 to 1:10.

Abstract: Stock developer solutions for photoresists contain an organic base free from metal ions and at least one compound having a specified weight average molecular weight that is selected from among polyethylene oxide compounds, polypropylene oxide compounds and ethylene oxide/propylene oxide adducts. The stock developer solutions may be diluted to requisite concentrations to prepare developer solutions for photoresists. By adding one or more of the specified compounds to the organic base free from metal ions, one can produce highly compatible stock developer solutions for photoresists that are concentrated, that have high stability in quality and that permit ease in handling and quality control. The stock developer solutions may be diluted to prepare developer solutions that are small in the tendency to foam and effective in defoaming, that assure uniform wetting and that are capable of forming resist patterns faithful to mask patterns.