TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - No general preparation is given. Preferred Compound: The bivalent group-containing compound (1) is preferably of formula (2).R11-R14=R1;andR11+R12,R13+R14=unsaturated condensed ring.Preferred Condition: The thermal decomposition temperature of bivalent coupling group-containing compound is 150-500 degrees C. The maximum absorption wavelength of bivalent coupling group-containing compound is ( lambda ) plus minus 150 nm, when the laser beam of pattern exposure has wavelength of ( lambda ) nm. Preferred Composition: The photoresist liquid comprises 50 mass% or more of bivalent coupling group-containing compound. SPECIFIC COMPOUNDS - 149 Bivalent group-containing compound (1) such as 2-(4-(dicyanomethylidene)-2,5-difluorocyclohexa-2,5-dien-1-ylidene)propanedinitrile of formula (3), 2-(8-(dicyanomethylidene)-1H,2H,3H,3aH,7aH,8H-cyclobuta(b)naphthalen-3-ylidene)propanedinitrile, 2-(4-(dicyanomethylidene)-2-fluorocyclohexa-2,5-dien-1-ylidene)propanedinitrile, 2-(2-chloro-4-(dicyanomethylidene)cyclohexa-2,5-dien-1-ylidene)propanedinitrile and 2-(4-(dicyanomethylidene)-1,4-dihydroanthracen-1-ylidene)propanedinitrile are disclosed.    EXAMPLE - 1,4-Dibromo-2,5-difluorobenzene (in g) (2.72), potassium iodide (24.9), iodination copper (9.53), and hexamethyl phosphoric triamide (30 ml) were mixed, heated at 150-160 degrees C under nitrogen atmosphere, extracted the organic layer and dried to obtain 2,5-difluoro-1,4-diiodo-cyclohexa-1 ,3-diene (2.93). Tetrahydrofuran (60 ml), 2,5-difluoro-1,4-diiodo-cyclohexa-1 ,3-diene (3.66), malononitrile (2.64), sodium hydride (1.44), and bis-triphenylphosphine palladium chloride (0.21) were heated and reacted to obtain 2-(4-(dicyanomethyl)-2,5-difluorophenyl)propanedinitrile (2.68). The obtained 2-(4-(dicyanomethyl)-2,5-difluorophenyl)propanedinitrile (3.36) was added to water (100 ml), and bromine water was slowly dripped to obtain 2-(4-(dicyanomethylidene)-2,5-difluorocyclohexa-2,5-dien-1-ylidene)propanedinitrile (3). The 2-(4-(dicyanomethylidene)-2,5-difluorocyclohexa-2,5-dien-1-ylidene)propanedinitrile simply provides etching mask having fine corrugated surface by performing pattern exposure without carrying out image development process.