Process of using high contrast photoresist developer with enhanced sensitivity to form positive resist image
US4822722A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 6, 1987 |
| Grant date | Apr 18, 1989 |
| Priority date | — |
| Expiry date | Nov 6, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/322
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
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 t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.