Substrate Bias Voltage Effect on Properties of TbCo Amorphous Films

The effect of substrate voltage on TbCo amorphous films is discussed. Changes in the saturation magnetization (Ms) and perpendicular magnetic anisotropy constant (Ku) were measured while varying the substrate bias voltage (Vb). The substrates were coated with Cr, which stabilized the bias voltage between target and substrate resulting in the reproducible film properties. Without Cr coating, Ms did not vary in a consistent manner, and most films tested had perpendicular and in-plane components. Varying electric potential and sputtering electrical discharge may have caused this inconsistency.