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 (M
s
) and perpendicular magnetic anisotropy constant (K
u
) were measured while varying the substrate bias voltage (V
b
). The substrates were coated with Cr, which stabilized the bias voltage between target and substrate resulting in the reproducible film properties. Without Cr coating, M
s
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.