Dynamic control of substrate bias for highly c-axis textured thin ferromagnetic CoCrTa film in inductively coupled plasma-assisted sputtering

Abstract

This study shows highly c-axis textured thin ferromagnetic Co-based alloy (CoCrTa) film growth in inductively coupled plasma (ICP)-assisted sputtering with an internal coil with an insulated surface. Dynamic control of the substrate bias achieved highly c-axis textured CoCrTa film with a thickness of 70nm in 3min depositions on a Si substrate. The prepared film showed a smooth, dense surface consisting of small crystal grains. The film had a perpendicular magnetic coercivity of 1030Oe and coercive squareness of 0.36. ICP-assisted sputtering with an internal coil with an insulated surface enabled higher-density (⩾1.0×1011cm−3) plasma with lower space potential (⩽30V) compared to ICP-assisted sputtering with bare coil systems. Therefore, the proposed bias control is quite effective for textured growth of thinner Co layers via the effect of a high flux of ions with proper energies. This method can be a candidate for the deposition technique of c-axis textured films as perpendicular magnetic recording media.

Control of resputtering in biased CoCrPt–SiO2 media to enhance grain decoupling and grain size distribution

“…Similarly, use of substrate bias for CoCrTa layer was reported to help the crystalline structure improved, exhibiting highly c-axis textured films. 10 In the inset, the corresponding magnetic properties of the biased medium indicate a coercivity H c of 2.15 kOe, a squareness of 0.94, and a sheared slope, implying magnetic isolation owing to the well-segregated microstructure. The rather low H c is thought to be due to not optimized Pt and Cr contents in the films.…”

Adhesion and Diffusion Barrier Properties of Ta Films Fabricated by Auxiliary Plasma Assisted Bias Sputtering

“…When a film is deposited by auxiliary plasma assisted bias sputtering, the mechanical properties of the film and interface characteristics change with the energy and flux of the ions incident to the surface of the growing films. 5,6) It is expected that the adhesion and diffusion barrier properties of Ta films can be improved by applying appropriate powers to the substrate and auxiliary plasma coil. In this study, we investigated the adhesion and diffusion barrier properties of a Ta film deposited by auxiliary plasma assisted bias sputtering at various substrate powers and coil input powers.…”