Influences of Surface Topography on the Flying Performances of a Sub-3 nm Air Bearing Slider

This paper studies the influences of the surface roughness and waviness on the static and dynamic flying performances of a thermal protrusion slider with flying height under 3 nm. Simulations show that the air bearing force and the contact force are proportional to the average roughness values of the surfaces, while the intermolecular force or the electrostatic force are the smallest for the smoothest surfaces when the minimum flying height is above a certain value. As a result, the total force on the slider is the largest on the smoothest surfaces in a certain minimum flying height region. When the minimum flying height is designed in this region, the flying ability of the slider is maximized. The energy analysis method is introduced to study the influences of the surface waviness on the dynamic performances of the slider. It is observed that the surface waviness may excite the slider to the bouncing state. The kinetic energy for maintaining the slider in the bouncing state comes mainly from the intermolecular force, while the air bearing force plays an important role in stabilizing the slider. The contributions of other forces, such as the friction force and the contact force, are also evaluated quantitatively. In order to improve the flying stabilities of the slider, the intermolecular force, the friction force and the electrostatic force should be reduced as much as possible. (C) 2010 The Japan Society of Applied Physics