Polishing pad and method for preparing a semiconductor device using the same

A process for preparing a polishing pad, which comprises:

• mixing a urethane-based prepolymer, a curing agent, and a foaming agent to prepare a composition for preparing a polishing layer;
• and
• injecting the composition for preparing a polishing layer into a mold and curing it to obtain a polishing pad comprising a polishing layer,
• wherein the curing agent comprises a tertiary amine-based polyol containing an ether bond, and the polishing pad has a surface roughness reduction rate (RSk (%)) of less than 50% as represented by the following Equation 1 and a recovery elasticity resistance index (RERI) of 40 or less as represented by the following Equation 2:
• RSk
• ⁢
• (
• %
• )
• =
• Sk
• 1
• -
• Sk
• 2
• Sk
• 1
• ⨯
• 100
• [
• Equation
• ⁢
• 1
• ]
• in Equation 1, Sk1 is the core roughness depth of the polishing pad before polishing, Sk2 is the core roughness depth of the polishing pad measured after it polishes a silicon oxide layer of a semiconductor substrate for 60 seconds under the conditions of a carrier pressurization of 4.0 psi, a carrier rotation speed of 87 rpm, and a platen rotation speed of 93 rpm while a calcined ceria slurry is sprayed at a rate of 250 ml/minute, and Sk1 and Sk2 are each a value calculated from data measured by an optical surface roughness meter for the polishing pad before polishing and the polishing pad after polishing in accordance with the ISO 25178-2 standard,
• [Equation 2]
• Recovery
• ⁢
• elasticity
• ⁢
• resistance
• ⁢
• index
• ⁢
• (
• RERI
• )
• =
• Rsk
• ⁢
• (
• %
• )
• 100
• ⁢
• (
• %
• )
• ⨯
• H
• 25
• [
• Equation
• ⁢
• 2
• ]
• in Equation 2, RSk (%) is as defined in Equation 1 above, H25 is the Shore D hardness of the polishing pad measured at 25° C., and the recovery elasticity resistance index (RERI) is a ratio between values excluding units,
• wherein the polishing pad has a tensile strength of 10 N/mm2 to 25 N/mm2, and an elongation of 80% to 320%.

A process for preparing a semiconductor device, which comprises:

• providing a polishing pad comprising a polishing layer;
• and
• relatively rotating the polishing surface of the polishing layer and the surface of an object to be polished while they are in contact with each other to polish the object to be polished,
• wherein the polishing pad comprises a polishing layer comprising a cured product of a composition comprising a urethane-based prepolymer, a curing agent, and a foaming agent, the curing agent comprises a tertiary amine-based polyol containing an ether bond, and the polishing pad has a surface roughness reduction rate (RSk (%)) of less than 50% as represented by the following Equation 1 and a recovery elasticity resistance index (RERI) of 40 or less as represented by the following Equation 2:
• RSk
• ⁢
• (
• %
• )
• =
• Sk
• 1
• -
• Sk
• 2
• Sk
• 1
• ⨯
• 100
• [
• Equation
• ⁢
• 1
• ]
• in Equation 1, Sk1 is the core roughness depth of the polishing pad before polishing, Sk2 is the core roughness depth of the polishing pad measured after it polishes a silicon oxide layer of a semiconductor substrate for 60 seconds under the conditions of a carrier pressurization of 4.0 psi, a carrier rotation speed of 87 rpm, and a platen rotation speed of 93 rpm while a calcined ceria slurry is sprayed at a rate of 250 ml/minute, and Sk1 and Sk2 are each a value calculated from data measured by an optical surface roughness meter for the polishing pad before polishing and the polishing pad after polishing in accordance with the ISO 25178-2 standard,
• Recovery
• ⁢
• elasticity
• ⁢
• resistance
• ⁢
• index
• ⁢
• (
• RERI
• )
• =
• Rsk
• ⁢
• (
• %
• )
• 100
• ⁢
• (
• %
• )
• ⨯
• H
• 25
• [
• Equation
• ⁢
• 2
• ]
• in Equation 2, RSk (%) is as defined in Equation 1 above, H25 is the Shore D hardness of the polishing pad measured at 25° C., and the recovery elasticity resistance index (RERI) is a ratio between values excluding units,
• wherein the polishing pad has a tensile strength of 10 N/mm2 to 25 N/mm2, and an elongation of 80% to 320%.