Abstract
The correlation between the cleanness of the substrate and the magnetoresistance (MR) is discussed for Co/Cu multilayers fabricated by a facing-targets sputtering method. Dry-etching of the substrate surface with RF plasma before film deposition results in a remarkable increase in the MR ratio, especially in multilayers whose Cu space layer thickness (dcu) is from 9Å to 11Å. From an analysis of the structure and magnetic properties of multilayers, it was concluded that an enlargement of the grain diameter in the multilayers led to an enhancement of the interlayer magnetic coupling, and resulted in the remarkable increase in the MR ratio. An exposing study of dry-etched substrates under various atmospheres, confirmed that dry-etching desorbed H2O and/or O2 gases from the surface and enhanced the mobility of sputtered adatoms on it.
