Biased pulse CMP groove pattern
The polishing pad is suitable for polishing or planarizing a wafer of at least one of semiconductor, optical and magnetic substrates. The polishing pad includes radial feeder grooves in a polishing layer separating the polishing layer into polishing regions. The radial feeder grooves extend at least from a location adjacent the center to a location adjacent the outer edge of the polishing pad. Each polishing region including a series of biased grooves that connects a pair of adjacent radial feeder grooves. A majority of the biased grooves having either an inward bias toward the center of the polishing pad or an outward bias for directing polishing fluid toward the outer edge of the polishing pad.
1. A polishing pad suitable for polishing or planarizing a wafer of at least one of semiconductor, optical and magnetic substrates, the polishing pad comprising the following:
a polishing layer having a polymeric matrix and a thickness, the polishing layer including a center, an outer edge and a radius extending from the center to the outer edge of the polishing pad;
radial feeder grooves in the polishing layer separating the polishing layer into polishing regions, the radial feeder grooves extending at least from a location adjacent the center to a location adjacent the outer edge of the polishing pad; and
each polishing region including a series of biased grooves connecting a pair of adjacent radial feeder grooves, a majority of the biased grooves having either an inward bias toward the center of the polishing pad or an outward bias toward the outer edge of the polishing pad, both the inward and outward biased grooves being for moving polishing fluid toward the outer edge of the polishing pad and either toward the wafer or away from the wafer depending upon inward bias or outward bias and the direction of rotation of the polishing pad wherein the total number of biased grooves is at least fifteen times the total number of radial feeder grooves.
2. The polishing pad of claim 1 wherein all polishing regions have the same bias.
3. The polishing pad of claim 1 including an inward bias for increasing slurry residence time under a wafer during counterclockwise rotation of the polishing pad and the wafer.
4. The polishing pad of claim 1 wherein the polishing pad includes at least three radial feeder grooves.
5. The polishing pad of claim 1 wherein the series of biased grooves connecting a pair of adjacent radial feeder grooves are parallel linear grooves.
6. A polishing pad suitable for polishing or planarizing a wafer of at least one of semiconductor, optical and magnetic substrates, the polishing pad comprising the following:
a polishing layer having a polymeric matrix and a thickness, the polishing layer including a center, an outer edge and a radius extending from the center to the outer edge of the polishing pad;
radial feeder grooves in the polishing layer separating the polishing layer into polishing regions, the polishing regions being circular sectors defined by two adjacent radial feeder grooves, a bias line bisecting the polishing regions, the radial feeder grooves extending at least from a location adjacent the center to a location adjacent the outer edge; and
each polishing region including a series of biased grooves connecting a pair of adjacent radial feeder grooves, a majority of the biased grooves having either an inward bias directed toward the center of the polishing pad at an angle of 20° to 85° from the bisect line or an outward bias directed toward the outer edge of the polishing pad at an angle of 95° to 160° from the bisect line, both the inward and outward biased grooves being for moving polishing fluid toward the outer edge of the polishing pad and either toward the wafer or away from the wafer depending upon inward bias or outward bias and the direction of rotation of the polishing pad wherein the total number of biased grooves is at least fifteen times the total number of radial feeder grooves.
7. The polishing pad of claim 6 wherein all polishing regions have the same bias.
8. The polishing pad of claim 6 including an inward bias for increasing slurry residence time under a wafer during counterclockwise rotation of the polishing pad and the wafer.
9. The polishing pad of claim 6 wherein the polishing pad includes at least three radial feeder grooves.
10. The polishing pad of claim 6 wherein the series of biased grooves connecting a pair of adjacent radial feeder grooves are parallel linear grooves.