TWM551548U - Elastic membrane for polishing head - Google Patents

Description

Elastic film for grinding head

The present invention relates to an elastic film, and more particularly to an elastic film mounted on the bottom of a polishing head of a chemical mechanical polishing machine.

With the evolution of semiconductor process technology, the thickness of coating and the control of surface flatness in the process are also receiving more and more attention. Chemical Mechanical Polishing (CMP) is one of the most commonly used surface leveling technologies. Adding a polishing liquid having abrasive particles such as cerium oxide, and physically grinding to remove excessive deposition material, unintended surface profile, and surface defects such as surface oxides on a substrate surface, The substrate is allowed to have a flat and regular surface.

Referring to Figures 1 and 2, a known elastic film 1 is mounted for mounting in a polishing apparatus 2 and can be used to adsorb a workpiece 3 to be polished, such as a semiconductor wafer, the polishing apparatus 2 comprising an elastic film A mounted polishing head 21, a polishing table 22 spaced apart from the polishing head 21 and the elastic film 1, and a liquid supply head 23 for supplying the polishing liquid to the polishing table 22. The polishing head 21 includes a metal seat body 211 defining a pressure supply passage 210 and assembled with the elastic film 1, and a pressure supply unit 212 penetrating the pressure supply passage 210, the metal seat body 211 and the elasticity A gas chamber 24 communicating with the pressure supply unit 212 is defined between the membranes 1. The polishing table 22 includes a support base 221, and a polishing pad 222 disposed above the support base 221 for grinding in contact with the workpiece 3 to be polished.

In use, the grinding device 2 adjusts the pressure in the gas chamber 24 by the pressure supply unit 212, and adjusts the contour of the elastic film 1 by pressure change to adsorb the workpiece 3 to be polished. When the grinding is started, the polishing head 21 is rotated relative to the polishing table 22, and the liquid supply head 23 supplies the polishing liquid to the polishing table 22, and the polishing head 21 supplies pressure through the pressure supply unit 212 to enter the polishing head. The air chamber 24 deforms the elastic film 1 downward and applies a downforce to the workpiece 3 to be polished. The workpiece 3 to be polished is in contact with the polishing table 22 and is rotated and rubbed to achieve a flattening. effect.

However, the elastic film 1 is known to be made of a polymer material having resilience in order to maintain its own elasticity, and a part of the heat energy generated during the grinding process is absorbed by the elastic film 1, resulting in the The elastic film 1 is slightly hot-melt deformed and is viscous with the workpiece 3 to be polished. At this time, even if the pressure supply unit 212 is adjusted to change the contour of the elastic film 1, the two cannot be separated. In addition to causing the machine of the grinding device 2 to crash abnormally, the above-mentioned sticking phenomenon requires additional manpower for troubleshooting, and also affects the overall line fluency of the workpiece 3 to be ground.

Accordingly, it is an object of the present invention to provide an elastic film that at least overcomes the disadvantages of the prior art.

Thus, the novel elastic film for a polishing head is suitable for being mounted on the bottom of the polishing head and for adsorbing a workpiece to be polished, the elastic film comprising a film body and an anti-adhesion layer. The film body includes a bottom wall and an outer ring wall extending upwardly from the periphery of the bottom wall and coupled to the polishing head, the bottom wall having an attachment surface at the bottom and facing the workpiece to be abraded. The anti-adhesion layer is coated on the bottom of the attachment surface and is interposed between the attachment surface and the workpiece to be polished.

The utility model has the advantages that the anti-adhesion layer can easily separate the elastic film from the workpiece to be polished, can reduce the risk of the machine crashing during the manufacturing process, and improve the smoothness of the production line.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to Figures 3, 4 and 5, a first embodiment of the novel elastic film 4 is suitable for mounting on the bottom of a polishing head 5 and for adsorbing a workpiece 6 to be polished, such as a semiconductor wafer. The polishing head 5 includes a disk body 51, a metal seat body 52 disposed in the disk body 51 and defining a vertically-connected pressure supply passage 520, and a pressure supply unit 53 extending through the pressure supply passage 520. . The elastic film 4 comprises a film body 41 and a layer of anti-adhesion layer 42.

The film body 41 is coupled to the polishing head 5 and includes a bottom wall 411 spaced apart from the metal seat 52 of the polishing head 5, and an upper portion extending from the periphery of the bottom wall 411 and attached to the polishing The outer ring wall 412 of the periphery of the metal seat 52 of the head 5 has a contact surface 414 at the bottom facing the workpiece 6 to be ground. The bottom wall 411, the outer ring wall 412 and the metal seat 52 cooperate to define a gas chamber 413 that communicates with the pressure supply unit 53.

The anti-adhesion layer 42 is interposed between the attachment surface 414 and the workpiece 6 to be polished, and is completely covered on the attachment surface 414. The anti-adhesion layer 42 is a high molecular polymer material which is resistant to high temperatures and is less prone to hot melt deformation, and is selected from the group consisting of epoxy resins, polyimine resins, acrylic resins, ruthenium rubber resins, and parylene resins. And its composition. In the first embodiment, the thickness of the anti-adhesion layer 42 is 1.5 μm, and when the thickness of the anti-adhesion layer 42 is more than 1.5 μm, the thickness is too thick to cause the elasticity to decrease and the hardness is too strong, thereby affecting The parameter conditions that need to be applied during grinding.

When the elastic film 4 is in use, the user can adjust the pressure in the air chamber 413 through the pressure supply unit 53, and further control the contour of the film body 41 to adsorb the workpiece 6 to be polished, or apply The workpiece 6 to be ground is pressed down and ground. After the workpiece 6 to be polished is polished, the adhesive layer 42 can reduce the adhesion between the film body 41 and the workpiece 6 to be polished due to heat, so the user can adjust the gas chamber 413. The internal pressure separates the elastic film 4 from the workpiece 6 to be polished, thereby reducing the probability of the machine being down due to the inability to separate.

Referring to Figure 6, a second embodiment of the novel elastic film 4 is substantially identical in construction to the first embodiment, except that the attachment surface 414 of the film body 41 has a centrally located circular center. At portion 415, the anti-adhesion layer 42 includes a first footprint 421 that only overlies the central portion 415. The purpose of the design is that the central portion 415 of the attachment surface 414 receives a large downforce during the grinding process, and the adhesion between the workpiece to be polished (not shown) is also maximized. Therefore, the second embodiment only covers the anti-adhesion layer 42 at the central portion 415. In addition to the easy separation between the film body 41 and the workpiece to be polished, the anti-adhesion layer can be reduced. The amount of use of 42 saves the cost of raw materials.

In the second embodiment, the area coverage of the first coverage area 421 of the anti-adhesion layer 42 on the attachment surface 414 is between about 2.5 and 32%, and the diameter of the attachment surface 414. For example, the first coverage area 421 is a concentric circle, and the diameter of the first coverage area 421 is between about 47 mm and 170 mm. When the area coverage of the first coverage area 421 is less than 2.5%, the adhesion between the film body 41 and the workpiece to be polished is still too large, and the two are not easily separated. When the area coverage of the first coverage area 421 is greater than 32%, since the central area of the film body 41 and the workpiece to be polished is the strongest, it is no longer necessary to reduce the adhesion between the two. There are obvious benefits, but it may increase the cost of materials.

Referring to Figure 7, a third embodiment of the present elastic film 4 is substantially identical in construction to the second embodiment, with the difference that the attachment surface 414 of the film body 41 also has a spaced-apart surrounding the center. The portion 415 is peripheral and has an annular peripheral portion 416. The anti-adhesion layer 42 further includes a second cover region 422 overlying the peripheral portion 416. In the third embodiment, the second covering area 422 is in a ring shape which is reduced by about 45 mm from the periphery of the attaching surface 414 toward the center, and the second covering area 422 is on the attaching surface 414. The area coverage is about 50%.

The improvement of this design is that between the elastic film 4 and the workpiece 6 to be polished, the frictional force of the region covered by the anti-adhesion layer 42 and the region not covered by the anti-adhesion layer 42 The frictional force is slightly different, so in the third embodiment, in addition to the first covering portion 421 in which the anti-adhesion layer 42 is coated on the central portion 415, the peripheral portion 416 is also covered. The second covering area 422 of the anti-adhesion layer 42 can make the frictional force of the inner and outer rings of the film body 41 relatively even.

It should be noted that the shape of the second covering area 421 is not limited by the ring shape, and may have different shapes depending on the film forming manner of the anti-adhesion layer 42. Referring to FIG. 8, a fourth embodiment of the present elastic film 4 is substantially identical in construction to the third embodiment, except that the peripheral portion 416 of the attachment surface 414 is discontinuously surrounding the central portion 415. The area coverage of the second coverage area 422 on the attachment surface 414 is between 40 and 50%.

It should be noted that in the first embodiment, the second embodiment, and the remaining variations of the third embodiment, the topography of the film body 41 may vary, and the film body 41 and the metal The number of the air chambers 413 defined by the cooperation of the seat body 52 can also be increased. Specifically, the film body 41 and the metal seat body 52 can cooperate to define a plurality of air chambers 413, and correspondingly, the metal The seat body 52 also forms a plurality of such pressure supply passages 520 corresponding to the air chambers 413. When a plurality of gas chambers 413 are provided, the pressure supply unit 53 can be adjusted to have different pressures in the gas chambers 413 to further adjust the application of different downforces to the workpiece 6 to be polished. Different parts. However, since the relative relationship between the elastic film 4 and the metal seat body 52 is not a technical feature of the present invention, it will not be described in detail herein.

In summary, the attachment surface 414 of the elastic film 4 of the present invention is coated with the anti-adhesion layer 42 to allow easy separation between the film body 41 and the workpiece 6 to be polished, thereby reducing the machine in the production process. The risk of crashing the machine and improving the smoothness of the production line can indeed achieve the purpose of this new model.

However, the above is only the embodiment of the present invention. When the scope of the novel implementation cannot be limited thereto, all simple equivalent changes and modifications according to the scope of the patent application and the contents of the patent specification are still This new patent covers the scope.

4‧‧‧elastic film
41‧‧‧ membrane body
411‧‧‧ bottom wall
412‧‧‧ outer ring wall
413‧‧ ‧ air chamber
414‧‧‧ Attachment
415‧‧‧ central part
416‧‧‧ Peripheral parts
42‧‧‧Anti-adhesive layer
421‧‧‧First coverage area
422‧‧‧Second coverage area
5‧‧‧ polishing head
51‧‧‧ dish
52‧‧‧Metal body
520‧‧‧pressure channel
53‧‧‧Pressure unit
6‧‧‧ workpiece to be ground

Other features and effects of the present invention will be apparent from the following description of the drawings, wherein: FIG. 1 is an incomplete schematic diagram illustrating the relative relationship between a workpiece to be polished and a known polishing apparatus; Is an incomplete side cross-sectional view showing the relative relationship between the workpiece to be polished and a known polishing head and an elastic film of the polishing apparatus; FIG. 3 is an incomplete side sectional view showing the first elastic film of the present invention. An embodiment is mounted under a metal seat of a polishing head and used to adsorb a workpiece to be polished; FIG. 4 is an incomplete side cross-sectional enlarged view showing the first embodiment mounted on the metal body and Figure 5 is a bottom view showing the distribution of an anti-adhesion layer of the first embodiment; Figure 6 is a bottom view showing a second embodiment of the elastic film of the present invention Figure 7 is a bottom view showing the distribution of the anti-adhesion layer of a third embodiment of the elastic film of the present invention; and Figure 8 is a bottom view showing the elasticity of the present invention a fourth of the membrane The distribution of the anti-adhesion layer of the examples.

4‧‧‧elastic film

41‧‧‧ membrane body

411‧‧‧ bottom wall

412‧‧‧ outer ring wall

413‧‧ ‧ air chamber

414‧‧‧ Attachment

42‧‧‧Anti-adhesive layer

5‧‧‧ polishing head

51‧‧‧ dish

52‧‧‧Metal body

520‧‧‧pressure channel

53‧‧‧Pressure unit

6‧‧‧ workpiece to be ground

Claims (9)

An elastic film for a polishing head, which is suitable for being mounted on the bottom of the polishing head and for adsorbing a workpiece to be polished, the elastic film comprising: a film body including a bottom wall, and a peripheral edge of the bottom wall Extending and connecting to the outer ring wall of the polishing head, the bottom wall has a bonding surface at the bottom and facing the workpiece to be polished; and an anti-adhesion layer covering the bottom of the attachment surface, and the middle The attachment surface and the workpiece to be polished. The elastic film for a polishing head according to claim 1, wherein the anti-adhesion layer comprises a first covering area completely covering the attaching surface. The elastic film for a polishing head according to claim 1, wherein the attachment surface has a central portion located at a center, and the anti-adhesion layer includes a first cover corresponding to the central portion covering the attachment surface. Area. The elastic film for a polishing head according to claim 3, wherein the attachment surface further has a peripheral portion spaced around the periphery of the central portion, the anti-adhesion layer further comprising a first cover The regions are concentrically spaced and correspond to a second footprint covering the peripheral portion of the attachment surface. The elastic film for a polishing head according to claim 1, wherein the material of the anti-adhesion layer is a polymer material. The elastic film for a polishing head according to claim 1, wherein the material of the anti-adhesion layer is selected from the group consisting of an epoxy resin, a polyimide resin, an acrylic resin, a ruthenium rubber resin, and a parylene system. Resin and combinations thereof. The elastic film for a polishing head according to claim 1, wherein the anti-adhesion layer has a thickness of not more than 1.5 μm. The elastic film for a polishing head according to claim 3, wherein an area coverage of the first coverage area of the anti-adhesion layer on the attachment surface is between 2.5% and 32%. The elastic film for a polishing head according to claim 4, wherein an area coverage of the first coverage area of the anti-adhesion layer on the attachment surface is between 2.5% and 32%, the resistance The area coverage of the second coverage area of the adhesive layer on the attachment surface is between 40% and 50%.