Polishing system, polishing pad and method of manufacturing semiconductor device
The present disclosure relates to a polishing system in which accuracy and easiness of attachment and detachment of a polishing pad to a surface plate are maximized, the polishing system including: a surface plate having a polishing pad mounted on an upper portion; and the polishing pad mounted on the surface plate, in which the polishing pad includes: a polishing surface and a surface plate attachment surface that is a rear surface of the polishing surface, the surface plate attachment surface includes: at least one engraved portion, the surface plate includes at least one embossed portion, and the embossed portion and the engraved portion have a complementary coupling structure, and a method of manufacturing a semiconductor device to which the polishing system is applied.
1. A polishing system comprising:
a surface plate having a polishing pad mounted on an upper portion of the surface plate;
wherein the polishing pad includes:
a polishing layer including the polishing surface; and
a cushion layer including a surface plate attachment surface,
the surface plate attachment surface includes: at least one engraved portion,
the surface plate includes at least one embossed portion, and
the embossed portion and the engraved portion have a complementary coupling structure, and
a depth D 2 of the engraved portion satisfies the correlation of Equation 2 below with a thickness D 3 of the cushion layer and a thickness D 1 of the polishing pad:
D 3< D 2< D 1. Equation 2
2. The polishing system of claim 1 ,
wherein the surface plate attachment surface includes: at least two engraved portions, and
when straight lines from a center of each of an arbitrary first engraved portion and second engraved portion among the at least two engraved portions to a center of the polishing pad on the surface plate attachment surface are a first straight line and a second straight line, an inner angle θ between the first straight line and the second straight line satisfies Equation 1 below:
−1<cos θ<1. Equation 1
3. The polishing system of claim 2 ,
wherein a center of the first engraved portion is a midpoint on a center line that bisects a planar shape of the first engraved portion.
4. The polishing system of claim 1 ,
wherein
the polishing surface includes at least one groove having a depth smaller than the thickness of the polishing layer, and
the depth D 2 of the engraved portion satisfies the correlation of Equation 3 below with a thickness D 4 of the polishing layer, a depth d 1 of the groove, and a thickness D 1 of the polishing pad:
D 1− D 4+(( D 4− d 1))/10< D 2< D 1− D 4+(( D 4− d 1))/2. Equation 3
5. The polishing system of claim 1 ,
wherein the surface plate attachment surface includes: a center area and an edge area,
the edge area is an area directly adjacent to a rim of the surface plate attachment surface and has a thickness R 1 along a straight line from the rim toward the center of the polishing pad, and
a straight distance from the rim of the surface plate attachment surface toward the center of the polishing pad corresponds to R 2 ,
a ratio of R 1 to R 2 is 0.2:1 to 0.5:1, and
the engraved portion is located in the edge area.
6. The polishing system of claim 5 ,
wherein the polishing surface includes: two or more grooves, and
the groove has a depth of 100 μm to 1500 μm, and
a width of 100 μm to 1000 μm, and
a pitch between adjacent two grooves is 2 mm to 70 mm.
7. The polishing system of claim 1 , further comprising a supply nozzle for applying a fluid to the polishing surface, as necessary.
8. The polishing system of claim 1 ,
further comprising a polishing head in which a pressurization load of the polishing pad to the surface plate is adjusted within a range of 2 psi to 7 psi.
9. A polishing pad comprising:
a polishing layer including the polishing surface; and
a cushion layer including the surface plate attachment surface,
wherein the surface plate attachment surface includes: at least one engraved portion,
the engraved portion has a complementary coupling structure with an embossed portion on a surface plate to be mounted through the surface plate attachment surface, and
a depth D 2 of the engraved portion satisfies the correlation of Equation 2 below with a thickness D 3 of the cushion layer and a thickness D 1 of the polishing pad:
D 3< D 2< D 1. Equation 2
10. The polishing pad of claim 9 ,
wherein the polishing surface includes at least one groove having a depth smaller than the thickness of the polishing layer, and
the depth D 2 of the engraved portion satisfies the correlation of Equation 3 below with a thickness D 4 of the polishing layer, a depth d 1 of the groove, and a thickness D 1 of the polishing pad:
D 1− D 4+(( D 4− d 1))/10< D 2< D 1− D 4+(( D 4− d 1))/2. Equation 3
11. The polishing pad of claim 10 ,
wherein the polishing surface includes: two or more grooves,
the groove has a depth of 100 μm to 1500 μm, and
a width of 100 μm to 1000 μm, and
a pitch between adjacent two grooves is 2 mm to 70 mm.
12. The polishing pad of claim 9 , wherein the polishing layer includes: a cured product of a preliminary composition including a urethane-based prepolymer, and the content of an isocyanate group (NCO %) in the preliminary composition is 5 wt % to 11 wt %.
13. A method of manufacturing a semiconductor device, the method comprising:
coupling a polishing pad including a polishing surface and a surface plate attachment surface on a rear surface of the polishing surface to a surface plate; and
polishing an object to be polished while relatively rotating the polishing pad and the object to be polished under a pressurization condition after a surface to be polished of the object to be polished is disposed to come into contact with the polishing surface,
wherein the object to be polished includes: a semiconductor substrate,
the polishing pad includes:
a polishing layer including the polishing surface; and
a cushion layer including the surface plate attachment surface,
the surface plate attachment surface includes: at least one engraved portion,
the surface plate includes: at least one embossed portion, and
in the coupling of the polishing pad to the surface plate, the embossed portion and the engraved portion are coupled to be engaged with each other, and
a depth D 2 of the engraved portion satisfies the correlation of Equation 2 below with a thickness D 3 of the cushion layer and a thickness D 1 of the polishing pad:
D 3< D 2< D 1. Equation 2
14. The method of claim 13 ,
wherein a load by which the surface to be polished of the object to be polished is pressurized on the polishing surface of the polishing layer is 0.01 psi to 20 psi.
15. The method of claim 13 ,
wherein rotation speeds of the polishing pad and the object to be polished are 10 rpm to 500 rpm, respectively.
16. The method of claim 13 , further comprising: a supply nozzle for applying a fluid to the polishing surface, as necessary.
17. The method of claim 13 ,
wherein the surface plate attachment surface includes: at least two engraved portions, and
when straight lines from a center of each of an arbitrary first engraved portion and second engraved portion among the at least two engraved portions to a center of the polishing pad on the surface plate attachment surface are a first straight line and a second straight line, an inner angle θ between the first straight line and the second straight line satisfies Equation 1 below:
−1<cos θ<1. Equation 1