Abstract: A liquid developer for electro photography which comprises a coloring agent, a coating agent, a resistivity controlling agent and a carrier liquid which disperses or dissolves the said three agents is suitable for providing high reproducibility of images when at least one of the following copolymers are used as said coating agent:(a) Copolymer of an acrylic acid compound represented by the following general formula (i) and a para-alkylstyrene represented by the following general formula (ii): ##STR1## (WHEREIN R.sub.1 is hydrogen or an alkyl group of 1-6 carbon atoms and R.sub.2 is hydrogen or C.sub.m H.sub.p X.sub.q wherein m=1-6 and p+q=2m+1 or p+q=m-1 and X is a halogen, amino group, secondary or tertiary amino group having an alkyl group of 1-4 carbon atoms, nitro group, cyano group or hydroxyl group) ##STR2## (WHEREIN R.sub.3 is an alkyl group of 2-18 carbon atoms).

Abstract: Method of making a semiconductor device which includes applying a solution of a heterocyclic ring-containing polymer in an organic solvent to a desired surface of a semiconductor body and removing the organic solvent from the solution by heat thereby to form a coating of a polymer on the surface, wherein the polymer is a reaction product of a diamine represented by the formula: ##STR1## with a tetracarboxylic acid or anhydride of it. Since the coating exhibits good thermal stability and good electrical properties when applied to the surface of the semiconductor, it is useful as a passivating film.