Development of columnar microstructure in magnetron sputter deposited CoPtCr/Cr magnetic thin films

Abstract

The present study examined the microstructure of CoPtCr alloy thin films, sputter deposited on Cr-underlayers varying in thic~ness from 25 to 1300 A. The investigation is an extension of work that examined the dependenceof the magnetic and noise characteristics on Cr-underlayer thickness. The cross-sectionaias well as planeview high resolutiontransmission electron micnweopy (HRTEM) of these films revealed that fine Cr-underlayer grains nucleate randomly and grow on the surface of a t " d N i p substrate during the early stage of sputter deposition. The heterogeneously nucleated Cr grains resutt in the formation of columnar grains through competitive growth. The width of columnar grains gradually increased with f h thickness and saturated at a thickness of about 850 A Cr-underlayer films. High resolution electron microscopy of these films showed the onset of physical separation h e e n columnar grains occurred b e e n 250 and 600 A. The present study provides bights into

Development of microstructure in Cr and Cr/CoCrPt films made by pulsed laser deposition

“…The ͕110͖ orientation becomes stronger with increasing film thickness. 14,15 The effects of other deposition conditions on Cr film growth have also been reported, though with less consensus. The ͕100͖ orientation is promoted by lower Ar pressure at elevated temperatures, 16 though on an unheated substrate a lower Ar pressure enhances the ͕110͖ orientation.…”