High-rate groove pattern
View Patent ↗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: r TR = 0.7 r * to 1.3 r * where r * = R C ( R R C ) 2 - cos ( 2 θ c 0 ) - sin ( 2 θ c 0 ) ( R / R C cos θ c 0 ) 2 - 1 ; with the inner region originating continuous grooves that extend uninterrupted to the outer region.
1. 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 comprising:
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 having multiple grooves, the multiple grooves having a high-rate path, at least fifty percent of the high-rate path being within twenty percent of a groove trajectory φ(r) in polar coordinates referenced to the concentric center of the polishing pad and defined in terms of (1) the distance R between the concentric center of the polishing pad and the rotational center of the substrate being polished, (2) the radius R c of the carrier fixture, and (3) the local angle θ c0 of grooves in the carrier fixture, defined with a groove equation as follows:
ϕ
(
r
)
=
∫
R
-
R
C
r
R
R
C
sin
ϕ
c
+
(
tan
θ
c
0
)
(
R
R
C
cos
ϕ
c
+
1
)
(
R
R
C
cos
ϕ
c
+
1
)
-
(
tan
θ
c
0
)
R
R
C
sin
ϕ
c
ⅆ
r
′
r
′
where
ϕ
c
=
cos
-
1
(
R
2
+
R
C
2
-
r
2
2
RR
C
)
-
π
for
values
of
r
from
(
R
-
R
C
)
to
(
R
+
R
C
)
the transition region being adjacent the outer region and within a radius from the center defined as follows:
r
TR
=
0.7
r
*
to
1.3
r
*
where
r
*
=
R
C
(
R
R
C
)
2
-
cos
(
2
θ
c
0
)
-
sin
(
2
θ
c
0
)
(
R
/
R
C
cos
θ
c
0
)
2
-
1
;
and wherein the inner region originates continuous grooves that extend uninterrupted to the outer region.
2. The polishing pad of claim 1 wherein the transition region includes arc-shaped grooves.
3. The polishing pad of claim 1 wherein the inner region has a groove path that is within twenty percent of the groove equation.
4. The polishing pad of claim 1 wherein the groove trajectory defined by the equation is from the θ c0 value being 0 to 90 degrees.
5. 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 comprising:
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 having multiple grooves, the multiple grooves having a high-rate path, at least fifty percent of the high-rate path being within ten percent of a groove trajectory φ(r) in polar coordinates referenced to the concentric center of the polishing pad and defined in terms of (1) the distance R between the concentric center of the polishing pad and the rotational center of the substrate being polished, (2) the radius R c of the carrier fixture, and (3) the local angle θ c0 of grooves in the carrier fixture, defined with a groove equation as follows:
ϕ
(
r
)
=
∫
R
-
R
C
r
R
R
C
sin
ϕ
c
+
(
tan
θ
c
0
)
(
R
R
C
cos
ϕ
c
+
1
)
(
R
R
C
cos
ϕ
c
+
1
)
-
(
tan
θ
c
0
)
R
R
C
sin
ϕ
c
ⅆ
r
′
r
′
where
ϕ
c
=
cos
-
1
(
R
2
+
R
C
2
-
r
2
2
RR
C
)
-
π
for
values
of
r
from
(
R
-
R
C
)
to
(
R
+
R
C
)
the transition region being adjacent the outer region and within a radius from the center defined as follows:
r
TR
=
0.8
r
*
to
1.2
r
*
where
r
*
=
R
C
(
R
R
C
)
2
-
cos
(
2
θ
c
0
)
-
sin
(
2
θ
c
0
)
(
R
/
R
C
cos
θ
c
0
)
2
-
1
;
and wherein the inner region originates continuous grooves that extend uninterrupted to the outer region and the transition region has an Area Groove /Area Total of 25 to 75 percent.
6. The polishing pad of claim 5 wherein the transition region includes arc-shaped grooves.
7. The polishing pad of claim 5 wherein the inner region has a groove path that is within twenty percent of the groove equation.
8. The polishing pad of claim 5 wherein the transition region includes circular-shaped grooves.
9. The polishing pad of claim 5 wherein the groove trajectory defined by the equation is from the θ c0 value being 30 to 60 degrees.
10. The polishing pad of claim 5 wherein the groove trajectory defined by the equation is from the θ c0 value being 40 to 50 degrees.