Laser zone texture on alternative substrate disks

A sealed, compact, and low power CO/sub 2/ pulsed laser is used to melt a focused microscopic area on an alternative glass ceramic substrate. By precisely controlling the laser power, pulse duration, pulse rate, and the disk movement, a well-refined array of bumps can be produced on the alternative substrate. The laser bump formation on the alternative substrate shows a positive-extending volume without any negative-extending volume. TEM electron diffraction shows a phase change from polycrystalline to amorphous in the melted area. In addition to the stress release, the domed bump formation could be doe to the volume expansion of newly formed amorphous phase. The CSS test results show that the supersmooth glass ceramic disk stiction can be reduced by one order of magnitude by applying laser zone texture. The transition zone width between laser texture and data zones can also be made as small as a few milli-inches to increase the recording area.