Results on electrical characterization of high Tcthin film surfaces modified by different surface treatments are presented. In particular, this work examines the effect of a Br/ethanol chemical etch, which has previously been shown to remove surface contamination while preserving the Cu(+2) oxidation state. Electrical measurements of YBa2Cu3O7−x/Au/Nb contact structures fabricated using polycrystalline, post‐annealed YBa2Cu3O7−xfilms with Br‐etched surfaces, show improvements of approximately one to two orders of magnitude in contact current densities and resistivities (resistance‐area products) relative to unetched contacts. The Br‐etch process has produced 10×10 &mgr;m2contacts with contact current densities greater than 400 A/cm2and RnA products as low as 4×10−7&OHgr;‐cm2.