Felfe & Lynch
Process of using high contrast photoresist developer with enhanced sensitivity to form positive resist image
 High contrast, sensitivity and bath life is obtainable by the addition of inorganic salts, preferably a carbonate, to an aqueous alkali metal base containing a carboxylated surfactant. The preferred alkali metal bases are potassium hydroxide or sodium hydroxide. The carboxylated surfactants contemplated by the invention are those encompassed with the formula: EQU R--O--(CH.sub.2 H.sub.4 O).sub.n --CH.sub.2 --COOX wherein R is a hydrocarbon radical of 6-18 carbon atoms alkyl radical, n has a value of 1-24 and X is a cation such as K.sup.+, Na.sup.+, or H.sup.+. The gain in sensitivity with the incorporation of an inorganic compound furnishing ions, typically an inorganic salt, to the developer with the carboxylated surfactant compared to the sensitivity obtained with developers with carboxylated surfactant and inorganic salts omitted was typically two fold and greater without a corresponding film loss. Examples of salts are those that contain the anions SO.sub.4.sup.2-, CO.sub.3.sup.2-, Cl.sup.-, PO.sub.4.sup.3-, Br.sup.-, NO.sub.3.sup.-, borates or silicates and the cations K.sup.+, Na.sup.+, Ca.sup.2+, Mg.sup.2+, Li.sup.+, or H.sup.+. Additionally, reagents capable of generating these anions and cations in solution are applicable provided that no substantial change in pH of the developer solution results. The extended bath life which is obtainable with the incorporation of the carboxylated surfactant is not adversely affected by the addition of the inorganic salts in the surfactant-containing developer compositions. 
Petrarch Systems, Inc.
G
G03F
inventional
Robert A. Valentine T. Roland L. James M. Susan A.
Owens Zuba Chin Lewis Ferguson