Polishing pad with grooves to reduce slurry consumption
View Patent ↗A chemical mechanical polishing pad having an annular polishing track and a concentric center O. The polishing pad includes a polishing layer having a plurality of pad grooves formed therein. The polishing pad is designed for use with a carrier, e.g., a wafer carrier, that includes a polishing ring having a plurality of carrier grooves. Each of the plurality of pad grooves has a carrier-compatible groove shape configured to enhance the transport of a polishing medium beneath the carrier ring on the leading edge of the carrier ring during polishing.
1. A polishing pad having a radius for use in conjunction with a carrier ring having at least one carrier groove and a leading edge relative to the polishing pad when the polishing pad and carrier ring are being used for polishing at least one of a magnetic, optical and semiconductor substrate in the presence of a polishing medium, the at least one carrier groove having an orientation relative to the carrier ring, the polishing pad comprising:
a) a polishing layer configured for polishing at least one of a magnetic, optical and semiconductor substrate in the presence of a polishing medium, the polishing layer including a circular polishing surface having an annular polishing track during polishing; and
b) at least one curved radial pad groove having a carrier-compatible groove shape with a continuous groove trajectory within the polishing track, the at least one curved radial pad groove including a point tangent to the radius of the polishing pad and the carrier-compatible groove shape determined as a function of the orientation of the at least one carrier groove so that the at least one carrier groove aligns with the at least one curved radial pad groove at a multitude of locations along the carrier-compatible groove shape with the continuous groove trajectory when the at least one carrier groove is on the leading edge of the carrier ring during polishing.
2. The polishing pad according to claim 1 , wherein the carrier-compatible groove shape corresponds to a curve defined by
ϕ
(
r
)
=
∫
0
Rpad
u
+
1
-
u
2
+
(
2
RRc
r
2
+
R
2
-
Rc
2
)
1
-
u
2
(
u
-
1
-
u
2
)
u
-
1
-
u
2
-
(
2
RRc
r
2
+
R
2
-
Rc
2
)
1
-
u
2
(
u
-
1
-
u
2
)
ⅆ
r
r
where
u
=
R
2
+
Rc
2
-
r
2
2
RRc
wherein R is the radial distance from a concentric center of the polishing pad to the center of the carrier ring, Rc is the radius of the carrier ring, Rpad is the radius of the polishing pad, and r is the radial distance from a concentric center of the polishing pad to a point on the carrier-compatible groove shape.
3. The polishing pad according to claim 1 , wherein the carrier-compatible groove shape corresponds to a curve defined by
ϕ
(
r
)
=
∫
0
Rpad
(
r
-
R
)
-
Rc
1
-
(
r
-
R
Rc
)
2
(
r
-
R
)
+
Rc
1
-
(
r
-
R
Rc
)
2
ⅆ
r
r
wherein R is the radial distance from a concentric center of the polishing pad to the center of the carrier ring, Rc is the radius of the carrier ring, Rpad is the radius of the polishing pad, and r is the radial distance from a concentric center of the polishing pad to a point on the carrier-compatible groove shape.
4. The polishing pad according to claim 1 , wherein the carrier-compatible groove shape traverses at least two-thirds of the polishing track.
5. The polishing pad according to claim 1 , wherein the polishing pad has a plurality of curved radial pad grooves having a carrier-compatible groove shape, the plurality of curved radial pad grooves being dispersed circumferentially around the polishing pad.
6. A polishing pad having a radius designed to cooperate with a carrier ring having at least one carrier groove and a leading edge relative to the polishing pad when the polishing pad and carrier ring are being used for polishing at least one of a magnetic, optical and semiconductor substrate in the presence of a polishing medium, the at least one carrier groove having an orientation relative to the carrier ring, the polishing pad comprising:
a) a polishing layer configured for polishing at least one of a magnetic, optical and semiconductor substrate in the presence of a polishing medium, the polishing layer including a circular polishing surface having an annular polishing track during polishing; and
b) at least one curved radial pad groove set having two or more curved radial pad grooves each with a continuous groove trajectory within the polishing track the two or more curved radial pad grooves including a point tangent to the radius of the polishing pad and the two or more curved radial pad grooves formed in the polishing layer and each having a carrier-compatible groove shape with the continuous groove trajectory within the polishing track that aligns with at least one carrier groove as a function of the orientation of the at least one carrier groove when the at least one carrier groove is located along the leading edge of the carrier ring during polishing.
7. The polishing pad according to claim 6 , wherein the carrier-compatible groove shape corresponds to a curve defined by
ϕ
(
r
)
=
∫
0
Rpad
u
+
1
-
u
2
+
(
2
RRc
r
2
+
R
2
-
Rc
2
)
1
-
u
2
(
u
-
1
-
u
2
)
u
-
1
-
u
2
-
(
2
RRc
r
2
+
R
2
-
Rc
2
)
1
-
u
2
(
u
+
1
-
u
2
)
ⅆ
r
r
where
u
=
R
2
+
Rc
2
-
r
2
2
RRc
wherein R is the radial distance from a concentric center of the polishing pad to the center of the carrier ring, Rc is the radius of the carrier ring, Rpad is the radius of the polishing pad, and r is the radial distance from a concentric center of the polishing pad to a point on the carrier-compatible groove shape.
8. The polishing pad according to claim 6 , wherein the carrier-compatible groove shape corresponds to a curve defined by
ϕ
(
r
)
=
∫
0
Rpad
(
r
-
R
)
-
Rc
1
-
(
r
-
R
Rc
)
2
(
r
-
R
)
+
Rc
1
-
(
r
-
R
Rc
)
2
ⅆ
r
r
wherein R is the radial distance from a concentric center of the polishing pad to the center of the carrier ring, Rc is the radius of the carrier ring, Rpad is the radius of the polishing pad, and r is the radial distance from a concentric center of the polishing pad to a point on the carrier-compatible groove shape.
9. The polishing pad according to claim 6 , wherein the carrier-compatible groove shape traverses at least two-thirds of the polishing track.
10. A method of making a rotational polishing pad for use with a carrier ring having at least one carrier groove and a leading edge relative to the polishing pad when the polishing pad and carrier ring are being used for polishing at least one of a magnetic, optical and semiconductor substrate in the presence of a polishing medium, the at least one carrier groove having an orientation relative to the carrier ring, the polishing pad having a radius, the method comprising:
a) determining a curved radial carrier-compatible groove shape with a continuous groove trajectory within the polishing track in substantial alignment with at least one carrier groove as a function of the orientation of the at least one carrier groove when the at least one carrier groove is located along the leading edge of the carrier ring during polishing; and
b) forming in the rotational polishing pad at least one pad groove having the carrier-compatible groove shape with a continuous groove trajectory and the at least one curved radial ad groove including a point tangent to the radius of the polishing pad.