Pinhole decoration in magnetic tunnel junctions

Magnetic tunnel junctions may experience failure due to local shortcuts in the insulating layers of such devices. To further develop magnetic tunnel j unctions. the areal density of pinholes must be analyzed. By electrodeposit ing copper, we have developed a method to image pinholes and analyze the de nsity of pinholes. Copper selectively nucleates at particular sites, formin g structures that can be visualized using an optical microscope. Using this method, we examined the change in size of grown copper structures over tim e and the increase in the areal density of defects as a function of the app lied electrodeposition potential. (C) 2000 American Vacuum Society. [S0734- 2101(00)05704-3].