Polishing pad and method of fabricating semiconductor device using the same

A method for producing a polishing pad, the method comprising steps of:

• preparing a urethane-based prepolymer composition;
• preparing a composition for producing a window containing the prepolymer composition and a curing agent;
• producing the window by curing the composition for producing a window;
• preparing a prepolymer composition;
• preparing a composition for producing a polishing layer containing the prepolymer composition, a foaming agent and a curing agent;
• producing a polishing layer by curing the composition for producing a polishing layer, and
• forming a through-hole in the polishing layer and inserting and bonding the produced window into and to the through-hole,
• wherein the urethane-based prepolymer has an unreacted isocyanate group (NCO) content (%) of 8 to 10%,
• wherein the curing agent is 4,4′-methylenebis(2-chloroaniline) (MOCA),
• wherein an isocyanate compound for producing the urethane-based prepolymer includes an aromatic diisocyanate compound,
• wherein the content of the curing agent is 15 parts by weight to about 28 parts by weight, based on 100 parts by weight of the urethane-based prepolymer,
• wherein the window has an absorbance change uniformity (ACU) of 1.5 to 2.5 as calculated by the following Equation 1,
• wherein the window has an absorbance difference (AD) of 0.0004 to 0.0008 calculated by the following Equation 2:
• ACU
• =
• Ax
• +
• Ay
• Az
• [
• Equation
• ⁢
• 1
• ]
• wherein:
• Ax is an absorbance of the window, measured with light having a wavelength of 550 nm,
• Ay is an absorbance of the window, measured with light having a wavelength of 750 nm, and
• Az is an absorbance of the window, measured with light having a wavelength of 650 nm,
• and
• AD
• =
• ❘
• "\[LeftBracketingBar]"
• Ax
• -
• Ay
• x
• -
• y
• ❘
• "\[RightBracketingBar]"
• .
• [
• Equation
• ⁢
• 2
• ]

A method for fabricating a semiconductor device, the method comprising steps of:

• 1) providing a polishing pad comprising a polishing layer and an endpoint detection window;
• 2) performing a polishing process on a semiconductor substrate while allowing the semiconductor substrate and the polishing layer to rotate relative to each other in a state in which a polishing-target surface of the semiconductor substrate is in contact with a polishing surface of the polishing layer;
• and
• 3) detecting a thickness of the semiconductor substrate and detecting an endpoint of the polishing process, through the window of the polishing pad,
• wherein the window comprises a cured product obtained by curing a window composition containing a urethane-based prepolymer and a curing agent, and the urethane-based prepolymer has an unreacted isocyanate group (NCO) content (%) of 8 to 10%,
• wherein the curing agent is 4,4′-methylenebis(2-chloroaniline) (MOCA),
• wherein an isocyanate compound for producing the urethane-based prepolymer includes an aromatic diisocyanate compound,
• wherein the content of the curing agent is 15 parts by weight to about 28 parts by weight, based on 100 parts by weight of the urethane-based prepolymer,
• wherein the window has an absorbance change uniformity (ACU) of 1.5 to 2.5 as calculated by the following Equation 1,
• wherein the window has an absorbance difference (AD) of 0.0004 to 0.0008 calculated by the following Equation 2:
• ACU
• =
• Ax
• +
• Ay
• Az
• [
• Equation
• ⁢
• 1
• ]
• wherein:
• Ax is an absorbance of the window, measured with light having a wavelength of 550 nm,
• Ay is the absorbance of the window, measured with light having a wavelength of 750 nm, and
• Az is the absorbance of the window, measured with light having a wavelength of 650 nm,
• and
• AD
• =
• ❘
• "\[LeftBracketingBar]"
• Ax
• -
• Ay
• x
• -
• y
• ❘
• "\[RightBracketingBar]"
• .
• [
• Equation
• ⁢
• 2
• ]