Mechanically controllable break junctions with nearly flat (at a lateral scale of similar or equal to 10 nm) electrodes and a greatly reduced number of surface defects were fabricated using a gentle procedure of surface modification. The modification process occurs at extremely close separations between the electrodes (similar or equal to1.5-2 Angstrom) where high electric fields and surface temperatures can be achieved at relatively low bias voltages. Experimental details, a possible physical mechanism and applications of the proposed technique are discussed.