Electromigration of Ag Ultrathin Films on Si(111) 7×7

Abstract

Scanning Auger electron spectroscopy observation revealed that a patch of Ag thin film with a thickness of several monolayers spread on the cathode side over the clean surface of Si(111) 7×7 with the application of dc current to the Si substrate. The spread-out layer had the constant thickness of 1.0 monolayer (=7.8×1014 atom/cm2) with √3×√3 structure. On the anode side the edge of the patch made no significant movement but a mixed phase of √3×√3 and 3×1 with a thickness of 0.8 monolayer appeared and extended from the edge toward the cathode. The mass transport was correlated with changes in the structure of the overlayer.

Step and Domain Boundary Effect of Surface Reconstruction to Si(111)-√ 3×√3-Ag

“…Superstructures introduced by Ag adsorption on Si (111) surface have been widely studied in the past decades [1][2][3][4][5][6][7][8]. In vacuum, clean Si(111) surface shows a Si(111)-7×7 (hereafter referred to as 7×7) reconstruction, with 102 Si atoms per 7×7 unitcell, characterized by huge unitcell, dangling bonds, stacking fault and dimmer rows, i.e., Dimer-Adatom-Stacking fault (DAS) structure [9,10].…”