A semiconductor apparatus includes a buffer layer formed on a substrate; an SLS buffer layer formed on the buffer layer; an electron transit layer formed on the SLS buffer layer and formed of a semiconductor material; and an electron supply layer formed on the electron transit layer and formed of a semiconductor material. The disk drive includes a disk plate that includes a plate body disposed substantially about and parallel with the disk for modifying air flow adjacent the disk during operation of the disk drive. The first and second manners may include first and second velocities and first and second trajectories of the headrest. A positional relation of the attended point and the target point is calculated. In another embodiment, the protective member is formed of a dissolvable member that dissolves within the body over a predetermined time period.