US Patent 8062103 High-rate groove pattern

The invention provides a polishing pad useful for polishing at least one of a magnetic, optical and semiconductor substrate in the presence of a polishing medium with a polishing pad. The polishing pad comprises a center, an inner region surrounding the center, a transition region connecting grooves from the inner region to an outer region surrounding the inner region. The outer region has multiple grooves with a high-rate path. The transition region is adjacent the outer region and within a radius from the center defined as follows: