WAFER POLISHING PAD AND METHOD OF WAFER POLISHING USING THE SAME
A wafer polishing pad includes a first pad having a first surface configured to receive a platen. A protrusion is disposed on the first surface of the first pad. The protrusion is disposed on an edge region of the first pad in a plan view such that a side surface of the protrusion makes contact with a side surface of the platen when the first pad is disposed on the platen.
This U.S. nonprovisional application claims priority under 35 U.S.C § 119 to Korean Patent Application No. 10-2017-0180750 filed on Dec. 27, 2017, in the Korean Intellectual Property Office, the entire contents of which are hereby incorporated by reference.
TECHNICAL FIELDThe present disclosure relate to a polishing pad, and more particularly, to a wafer polishing pad and a method of wafer processing using the wafer polishing pad.
DISCUSSION OF THE RELATED ARTAn integrated circuit is generally formed by successively disposing conductors, semiconductors, and/or insulators on a wafer. After each layer is disposed, the layer is etched to define the circuit. As layers are successively disposed and etched, the wafer gradually becomes rough on its exposed surface. To correct for this roughness, the wafer may be periodically planarized to flatten the exposed surface of the wafer. A chemical mechanical polishing process may be employed in planarizing the wafer. The chemical mechanical polishing process may use a polishing pad to polish the wafer.
SUMMARYA wafer polishing pad includes a first pad having a first surface configured to receive a platen. A protrusion is disposed on the first surface of the first pad. The protrusion is disposed on an edge region of the first pad in a plan view such that a side surface of the protrusion makes contact with a side surface of the platen when the first pad is disposed on the platen.
A wafer polishing pad includes a top surface including a groove. A first bottom surface opposite to the top surface corresponds to a central region of the polishing pad. A second bottom surface opposite to the top surface corresponds to an edge region of the polishing pad. The second bottom surface is located at a lower level than that of the first bottom surface.
A wafer polishing method includes preparing a polishing pad comprising a first pad and a protrusion. The protrusion is disposed on an edge region of a first surface of the first pad. The polishing pad is placed on a platen such that the first surface of the first pad faces the platen. A wafer is polished using the polishing pad. Placing the polishing pad on the platen includes causing the protrusion of the polishing pad to make contact with a sidewall of the platen.
A wafer polishing pad includes a polishing surface configured to mechanically polish a wafer. A receiving surface, opposite to the polishing surface, is configured to make contact with a top surface of a platen. A ring is disposed on the receiving surface and the ring is configured to make contact with a side surface of the platen.
A more complete appreciation of the present disclosure and many of the attendant aspects thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
In describing exemplary embodiments of the present disclosure illustrated in the drawings, specific terminology is employed for sake of clarity. However, the present disclosure is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents which operate in a similar manner. In the specification and the various figures, like reference numerals may indicate like components.
Exemplary embodiments of the present invention may utilize a wafer polishing pad and a wafer polishing method using the same.
Referring to
The first pad 100 may have a first surface 100a and a second surface 100b opposite to the first surface 100a. The second surface 100b of the first pad 100 may correspond to a top surface of the polishing pad 10 while the first surface 100a of the first pad 100 may correspond to a bottom surface of the polishing pad. The second surface 100b of the first pad 100 may serve as a polishing surface. For example, the second surface 100b of the first pad 100 may make contact with and polish the polishing target. The second surface 100b of the first pad 100 may be relatively rough, for example, the second surface 100b may be rougher than the first surface 100a. The first pad 100 may have a uniform thickness. For example, central and edge regions of the first pad 100 may have the same or similar maximum thickness. The second surface 100b of the first pad 100 may be straight and unbent. For example, the second surface 100b of the first pad 100 may have central and edge regions whose respective topmost portions are located at substantially the same level. The edge region of the second surface 100b of the first pad 100 may indicate a zone overlapped with the protrusion 300.
A plurality of grooves 210 may be disposed on the second surface 100b of the first pad 100. As illustrated in
The protrusion 300 may be disposed on the first surface 100a of the first pad 100. The first surface 100a of the first pad 100 may be relatively flat. When viewed in plan as illustrated in
For example, the protrusion 300 and the first pad 100 may be integrally formed so as to constitute a single unitary body. The protrusion 300 and the first pad 100 may be connected to each other without a boundary, and may include the same material. The protrusion 300 may alternatively be formed by attaching a separate structure (e.g., a preliminary protrusion) onto the first surface 100a of the first pad 100. In this case, the protrusion 300 and the first pad 100 may include the same or different materials, and an adhesion may be used to attach the first pad 100 and the protrusion 300. The protrusion 300 may include a polymer, but the protrusion 300 may be formed of another material.
An adhesive layer 500 may further be disposed on the first surface 100a of the first pad 100. The first pad 100 may thus have the adhesive layer 500 attached onto an area of the first surface 100a that is not covered with the protrusion 300. The adhesive layer 500 may have a thickness that is less than the height H of the protrusion 300. The bottom surface 300a of the protrusion 300 may be located at a lower level than that of a bottom surface of the adhesive layer 500. The adhesive layer 500 may further extend along an inside surface 300c (e.g. inside facing sidewall) of the protrusion 300. The adhesive layer 500 may include a polymer.
Referring to
The second pad 200 may be disposed on the first pad 100. The second pad 200 may have a plurality of pores at least partially penetrating the second pad 200. The second pad 200 may include, for example, a polymer such as polyurethane. The second pad 200 may have a first surface facing the first pad 100 and a second surface 200b opposite to the first surface. The second surface 200b of the second pad 200 may correspond to a top surface of the polishing pad 11. The second surface 200b of the second pad 200 may serve as a polishing surface. A plurality of grooves 210 may be disposed on the second surface 200b of the second pad 200. The grooves 210 may have planar shapes and may be at least similar to the grooves 210 discussed above with reference to
An adhesive pattern 150 may be interposed between the first pad 100 and the second pad 200. The second pad 200 may be attached through the adhesive pattern 150 to the first pad 100. The adhesive pattern 150 may include an insulating polymer. Central and edge regions of the adhesive pattern 150 may have substantially the same maximum thickness as each other.
Referring to
A plurality of vent grooves 310 may be disposed in the protrusion 300. The vent grooves 310 may be disposed on and may penetrate the bottom surface 300a of the protrusion 300. As illustrated in
The protrusion 300 may be formed on the first pad 100, and then the protrusion 300 may be partially removed to form the vent grooves 310. According to an exemplary embodiment of the present disclosure, the formation of the vent grooves 310 may include preparing a plurality of preliminary protrusions and attaching the preliminary protrusions onto the first surface 100a of the first pad 100 so as to be spaced apart from each other. In this case, the protrusion 300 may include a plurality of sub-protrusions spaced apart from each other, and the vent grooves 310 may be disposed between each of the plurality of sub-protrusions.
A mark 400 may further be disposed on the bottom surface 300a of the protrusion 300. The mark 400 may be a character or figure displayed on the bottom surface 300a of the protrusion 300. For example, the mark 400 may be formed by attaching a pattern onto the bottom surface 300a of the protrusion 300. Alternatively, the mark 400 may be a recession formed within the bottom surface 300a of the protrusion 300. A planar arrangement of the mark 400 is not limited to that shown, and various different arrangements are within the scope of the present disclosure.
The first pad 100 may include an adhesive layer 500 on its first surface 100a exposed by (e.g. not covered by) the protrusion 300. The adhesive layer 500 may further cover the inside surface 300c of the protrusion 300. An attaching process of the adhesive layer 500 and functions of the vent grooves 310 are described in greater detail below.
Referring to
A wafer polishing method according to exemplary embodiments of the present disclosure is described in detail below.
Referring to
Referring to
Referring to
The polishing pad 11 may be used to polish a wafer WF (S30). In some exemplary embodiments of the present disclosure, the wafer WF may be prepared. The wafer carrier 2000 may use vacuum pressure to hold the wafer WF so as to cause a polishing target surface of the wafer WF to face the polishing pad 11. The wafer carrier 2000 may be driven to move up and down by an elevation unit. The wafer carrier 2000 may move downward to contact with the polishing pad 11 when a polishing process is performed. The wafer carrier 2000 may rotationally move to rotate the wafer WF during the polishing process.
The slurry supply 3000 may provide slurry onto the top surface of the polishing pad 11. A material of the slurry may be determined based on a kind and material of the polishing target surface of the wafer WF. The slurry may chemically polish the polishing target surface of the wafer WF, while contacting the polishing target surface of the wafer WF. For example, the polishing target surface of the wafer WF may change into an easily removable state due to reaction with the slurry.
The polishing pad 11 may be supported by and may rotate together with the platen 1000 during the polishing process. As discussed above, the pores of the first pad 100 or of the second pad 200 may receive the slurry. The polishing target surface of the wafer WF and the top surface of the polishing pad 11 may abrade against each other to mechanically polish the polishing target surface of the wafer WF. The grooves 210 may serve as paths for the slurry and polishing residues. When the central point of the polishing pad 11 is misaligned with the central point of the platen 1000, the slurry in the grooves 210 may move unintentionally. In some exemplary embodiments of the present disclosure, since the polishing pad 11 and the platen 1000 are accurately aligned with each other due to the protrusion 300, when the platen 1000 moves in rotary motion, the slurry may be evenly distributed in the grooves 210 and slurry residues may be satisfactorily discharged/removed from the grooves 210. As a result, the wafer WF may be evenly polished on its polishing target surface.
The pad conditioner 4000 may be installed adjacent to the platen 1000. The pad conditioner 4000 may move rotationally and reciprocally. The pad conditioner 4000 may contact the top surface of the polishing pad 11 and maintain an even surface roughness of the top surface of the polishing pad 11. Therefore, even though the polishing process is performed for a long time, the wafer WF may be satisfactorily polished on its polishing target surface.
When the diameter A1 of the polishing pad 11 is the same as or less than the diameter A2 of the platen 1000, the pad conditioner 4000 may come into contact with the platen 1000 (e.g., with an edge portion of the platen 1000) during the operation of the pad conditioner 4000. In this case, the pad conditioner 4000 and/or the platen 1000 may suffer from damage. In some exemplary embodiments of the present disclosure, the diameter A1 of the polishing pad 11 may be greater than the diameter A2 of the platen 1000. For example, the diameter A1 of the polishing pad 11 may be approximately 5 to 10 mm larger than the diameter A2 of the platen 1000. The pad conditioner 4000 and the platen 1000 may accordingly be prevented from colliding against each other.
When the diameter A1 of the polishing pad 11 is greater than the diameter A2 of the platen 1000, an edge portion of the polishing pad 11 might not be supported by the platen 1000. When no protrusion 300 is provided, edge portions of the first and second pads 100 and 200 may bend down lower than central portions of the first and second pads 100 and 200. For example, the edge portions not being supported by the platen 1000 may tend to bend inwardly toward the platen 1000. The top surface of the polishing pad 11 may thus be bent. The bending portion of the top surface of the polishing pad 11 may be excessively abraded by the pad conditioner 4000, with the result that the polishing pad 11 may decrease in life span. In some exemplary embodiments of the present disclosure, the polishing pad 11 may include the protrusion 300. The protrusion 300 may be disposed on the edge portion of the first pad 100. Hence, the edge portion of polishing pad 11 may be supported and this support may prohibit the first pad 100 from bending down. When the height H of the protrusion 300 is less than 1 mm, it may be unlikely that the protrusion 300 sufficiently prevents the bending of the polishing pad 11. In some exemplary embodiments of the present disclosure, the height H of the protrusion 300 may fall within a range equal to or greater than 1 mm, and thus the polishing pad 11 may be sufficiently prevented from bending. The polishing pad 11 may accordingly be prevented from being excessively abraded on its top surface. Thus, the polishing pad 11 may increase in life span.
According to exemplary embodiments of the present disclosure, a polishing pad may include a protrusion. The polishing pad may be disposed on the top surface of a platen. The protrusion may be disposed on the sidewall of the platen. The protrusion may accurately and quickly align the polishing pad with the platen. The process time may then decrease. The protrusion may rigidly fix the polishing pad to the platen.
The protrusion may prevent the polishing pad from bending down on the platen. The protrusion may suppress excessive abrasion of the polishing pad, and as a result, the polishing pad may increase in life span.
Exemplary embodiments described herein are illustrative, and many variations can be introduced without departing from the spirit of the disclosure or from the scope of the appended claims. For example, elements and/or features of different exemplary embodiments may be combined with each other and/or substituted for each other within the scope of this disclosure and appended claims.
Claims
1. A wafer polishing pad, comprising:
- a first pad having a first surface configured to receive a platen; and
- a protrusion disposed on the first surface of the first pad,
- wherein the protrusion is disposed on an edge region of the first pad in a plan view such that a side surface of the protrusion makes contact with a side surface of the platen when the first pad is disposed on the platen.
2. The wafer polishing pad of claim 1, wherein the protrusion exposes a central region of the first surface of the first pad, and when viewed in the plan view, the protrusion circumscribes the central region of the first pad.
3. The wafer polishing pad of claim 1, wherein the protrusion comprises a vent groove disposed within a bottom surface of the protrusion.
4. The wafer polishing pad of claim 3, wherein a floor surface of the vent groove is located at substantially a same level as that of the first surface of the first pad.
5. The wafer polishing pad of claim 3, further comprising a mark disposed on the bottom surface of the protrusion.
6. The wafer polishing pad of claim 3, further comprising an adhesive layer covering a portion of the first surface of the first pad,
- wherein the portion of the first surface of the first pad is exposed by the protrusion.
7. The wafer polishing pad of claim 1, wherein a groove is disposed on a second surface of the first pad,
- wherein the second surface of the first pad is opposite to the first surface.
8. The wafer polishing pad of claim 1, further comprising:
- a second pad disposed on the first pad; and
- an adhesive layer disposed between the first pad and the second pad.
9. The wafer polishing pad of claim 8, wherein a groove is disposed on a second surface of the second pad,
- wherein the second surface of the second pad faces away from the first pad.
10. The wafer polishing pad of claim 1, wherein a topmost portion of an edge region of a second surface of the first pad is located at substantially the same level as that of a topmost portion of a central region of the second surface of the first pad,
- wherein the second surface of the first pad is opposite to the first surface of the first pad.
11. A wafer polishing pad, comprising:
- a top surface including a groove;
- a first bottom surface opposite to the top surface and corresponding to a central region of the polishing pad; and
- a second bottom surface opposite to the top surface and corresponding to an edge region of the polishing pad,
- wherein the second bottom surface is located at a lower level than that of the first bottom surface.
12. The wafer polishing pad of claim 11, wherein the second bottom surface has a closed loop shape.
13. The wafer polishing pad of claim 11, further comprising a vent groove disposed within the second bottom surface,
- wherein a floor surface of the vent groove is connected to the first bottom surface.
14. The wafer polishing pad of claim 13, further comprising an adhesive layer disposed on the first bottom surface.
15-20. (canceled)
21. A wafer polishing pad, comprising:
- a polishing surface configured to mechanically polish a wafer;
- a receiving surface, opposite to the polishing surface, configured to make contact with a top surface of a platen; and
- a ring disposed on the receiving surface and configured to make contact with a side surface of the platen.
22. The wafer polishing pad of claim 21, wherein the ring of the polishing wafer is configured to buttress a portion of the polishing surface that extends beyond the platen.
23. The wafer polishing pad of claim 21, wherein the wafer polishing pad comprises a first pad and a second pad that are joined together by an adhesive layer, the first pad including the polishing surface and the second pad including the receiving surface.
Type: Application
Filed: Aug 1, 2018
Publication Date: Jun 27, 2019
Inventors: Seok Ryul Kim (Hwaseong-si), Sunghyup Kim (Hwaseong-si), Sanghoon Lee (Seoul)
Application Number: 16/052,294