POLISHING PAD, PREPARATION METHOD THEREOF AND METHOD FOR PREPARING SEMICONDUCTOR DEVICE USING SAME
The embodiments relate to a polishing pad for use in a chemical mechanical planarization (CMP) process of semiconductors, to a process for preparing the same, and to a process for preparing a semiconductor device using the same. The polishing pad according to the embodiment adjusts the surface roughness characteristics of the polishing pad after polishing, whereby the polishing rate can be enhanced, and the surface residues, surface scratches, and chatter marks of the wafer can be remarkably reduced.
1 . A process for preparing a polishing pad, which comprises:
mixing a urethane-based prepolymer, a curing agent, and a foaming agent to prepare a raw material mixture; and
injecting the raw material mixture into a mold and curing it to form a polishing pad,
wherein the polishing pad satisfies the following Relationships 1 and 2 in the areal material ratio curve based on the ISO 25178-2 standard after 25 dummy wafers are polished for 60 seconds each and two monitoring wafers are polished for 60 seconds each, each of the wafers being a silicon oxide wafer (or PETEOS wafer), while a calcined ceria slurry is sprayed at a rate of 200 cc/min on to the polishing pad, and when the polishing pad after the polishing is measured with an optical surface roughness meter:
0.02
≤
Vmp
(
10
)
/
Vvv
(
80
)
≤
1.
[
Relationship
1
]
0.005
≤
Vmp
(
10
)
/
Vmc
(
10
,
8
0
)
≤
2
.
0
0
0
[
Relationship
2
]
in Relationships 1 and 2,
Vmp(10) is the material volume of the peaks corresponding to the upper 10%,
Vvv(80) is the void volume of the valleys corresponding to the upper 80% to 100%, and
Vmc(10,80) is the material volume of the core corresponding to the upper 10% to 80%.
2 . The process for preparing a polishing pad of claim 1 , wherein the foaming agent comprises a solid phase foaming agent, a gas phase foaming agent, or a mixed foaming agent thereof, and the solid phase foaming agent is purified by a purification system for a solid phase foaming agent.
3 . The process for preparing a polishing pad of claim 1 , wherein the mixing is carried out using a mixing head at a speed of 500 rpm to 10,000 rpm.
4 . A process for preparing a polishing pad, which comprises:
mixing a urethane-based prepolymer, a curing agent, and a foaming agent to prepare a raw material mixture; and
injecting the raw material mixture into a mold and curing it to obtain a polishing pad,
wherein the polishing pad satisfies the following Relationship 4 in the areal material ratio curve based on the ISO 25178-2 standard after 25 dummy wafers are polished for 60 seconds each and two monitoring wafers are polished for 60 seconds each, each of the wafers being a silicon oxide wafer (or PETEOS wafer), while a calcined ceria slurry is sprayed at a rate of 200 cc/min on to the polishing pad, and when the polishing pad after the polishing is measured with an optical surface roughness meter:
0.002
≤
Vmp
(
10
)
/
Vv
(
0
)
≤
0
.
1
0
0
[
Relationship
4
]
in Relationship 4, Vmp(10) is the material volume of the peaks corresponding to the upper 10%, and Vv(0) is the total void volume.