KR20030047542A - Top ring of a chemical-mechanical polishing apparatus - Google Patents

Abstract

PURPOSE: An upper ring of a CMP(Chemical Mechanical Polishing) apparatus is provided to be capable of uniformly polishing a wafer by equally contacting a polishing pad on the surface of the wafer using the weight of liquid. CONSTITUTION: An upper ring of a CMP apparatus is provided with an upper ring arm(32) capable of rotating the upper ring, a rotating shaft(110) having an air path(111), a body(120) having a mounting space(121) connected with the lower portion of the rotating shaft for rotating with the rotating shaft, a pressing plate(130) inserted into the upper portion of the mounting space of the body for connecting with the lower portion of the rotating shaft, an adsorption plate(140) having an air suction hole(141) inserted into the lower portion of the mounting space of the body, an air suction pipe(150) inserted through the pressing plate into the air path of the rotating shaft, and pressing liquid(160) stored a closed space formed by the pressing plate and adsorption plate for uniformly pressing the adsorption plate.

Description

TOP RING OF A CHEMICAL-MECHANICAL POLISHING APPARATUS}

The present invention relates to an upper ring of a chemical-mechanical polishing ("CMP") device, and more particularly, by using a liquid as a load applying medium to adhere the wafer surface to a polishing pad during polishing. It relates to a top ring of a CMP device that is made of a viscous liquid to balance the wafer surface to the polishing pad in a balanced manner, and the structure is simple and easy to maintain and repair.

Increasing the degree of integration of semiconductor devices reduces the size of the devices and, consequently, the multilayer interconnection process necessary for the implementation of complex functional integrated circuits, has become more and more important for global planarization in interlayer dielectrics (ILDs). I'm going.

During the planarization process, the CMP process is widely used in recent years. The CMP process is a chemical removal process and a mechanical removal process, in which a slurry containing abrasives and chemicals is brought into close contact with a polishing pad on a polishing pad using a step method. (Slurry) is injected between the wafer and the polishing pad to planarize the surface of the wafer.

Referring to the CMP apparatus for performing a conventional CMP process with reference to the accompanying drawings as follows.

1 is a cross-sectional view schematically showing a conventional CMP apparatus, and FIG. 2 is a cross-sectional view showing an upper ring of a conventional CMP apparatus.

As shown, the conventional CMP apparatus forms a tub 11 formed in a predetermined shape on the upper side of the main body 10, and a polishing platen 20 is installed inside the tub 11. On top of the polishing platen 20, a top ring head 30 and a slurry supply nozzle 40 are respectively provided.

The polishing platen 20 is provided with a polishing pad 21 on which a surface of the wafer W is closely adhered to the upper surface thereof, and has a polishing pad 21 for polishing. The polishing platen 20 is mechanically connected to a rotating motor (not shown) to provide a rotational force of the rotating motor. The receiving rotating shaft 22 is formed. Therefore, the polishing platen 20 performs a simple rotational motion by driving the rotating motor when polishing the wafer W. FIG.

The upper ring head 30 is coupled to the upper ring 31 for vacuum suction of the wafer W to the lower side and the upper ring 31, and the upper ring 31 is polished to a predetermined pressure during polishing. ) And an upper ring arm 32 which rotates at the same time as being in close contact with < RTI ID = 0.0 >) or < / RTI >

As shown in FIG. 2, the upper ring 31 has a path through which air is sucked into the upper portion of the main body 31a by a vacuum pump (not shown) or compressed air is supplied from the compressed air supply unit (not shown). The rotating shaft 31c which vertically provided the supply hole 31b to provide is joined.

The main body 31a is formed to vertically penetrate through the main through hole 31e communicating with the supply hole 31b by the expansion tube 31d, and has a plurality of grooves so as to pass through the main through hole 31e on the lower side thereof. 31f) is formed and the pressure plate 31g is coupled.

The pressure plate 31g forms a plurality of through holes 31h connected to each of the grooves 31f, and the guide ring 31i is coupled to the lower edge.

Therefore, when the upper ring 31 vacuum-adsorbs the wafer W, air is sucked through the through-hole 31h of the pressure plate 31g by the vacuum pump, and when the polishing is carried out, the pressure plate 31g is removed from the compressed air supply. The compressed air is supplied through the through hole 31h to compress the wafer W to the polishing pad 21.

On the other hand, a ball 31j is interposed between the main body 31a and the rotating shaft 31c, and the ball 31j is polished from the rotating shaft 31c by the surface of the wafer W mounted on the main body 31a. It is in close contact with the pad 21.

The upper ring arm 32 loads / unloads the upper ring 31 into the polishing pad 21 by a driving means composed of a drive motor, a timing belt, a pneumatic cylinder, and the like, which are not shown. The polishing pad 21 is rotated in close contact with a predetermined pressure.

The slurry supply nozzle 40 supplies a slurry to the polishing pad 21 during polishing of the wafer W.

In the CMP apparatus, when the wafer is polished, the upper ring supplies compressed air as a load applying medium for bringing the surface of the wafer into close contact with the polishing pad, so that the load applied to the surface of the wafer is not balanced. Non-uniform adhesion of the wafer causes non-uniform polishing of the wafer, resulting in defects in the wafer during the subsequent process, and complicated structure of the upper ring to uniformly supply compressed air to the lower side of the pressure plate. There was a problem that cost a lot of money and effort.

Of course, the surface of the wafer mounted on the main body is brought into close contact with the polishing pad by the ball interposed between the main body of the upper ring and the rotating shaft, but this not only complicates the structure of the upper ring but also compresses the compressed air used as a load applying medium. Due to its characteristics, there is still a problem in that it is not a fundamental countermeasure to prevent unbalanced polishing of the wafer.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to balance a wafer surface with a polishing pad by viscosity of the liquid by using liquid as a load applying medium for bringing the wafer surface into close contact with the polishing pad during polishing. The wafer is uniformly polished so that the wafer is uniformly polished, and the polishing is continuously used without supplying a liquid, which is a load applying medium to the wafer, to provide a top ring of the CMP device, which is simple in structure and easy to maintain. have.

The present invention for realizing the above object is, by pumping a vacuum pump, the upper ring which vacuum-adsorbed the wafer to the lower side, and coupled to the upper side of the upper ring, by pressing and rotating the upper ring to the polishing pad at a constant pressure An upper ring head of a CMP apparatus comprising an upper ring arm for polishing a wafer, the upper ring head comprising: a rotating shaft rotatably coupled to the upper ring arm and having an air suction path connected to a vacuum pump therein; A main body having a mounting space having a lower side opened therein, the lower end of the rotating shaft being inserted into the upper side of the mounting space, and coupled to rotate together; A pressure plate coupled to the lower end of the rotating shaft so as to slide in a vertical direction in a mounting space of the main body; An adsorption plate inserted into the lower end of the mounting space of the main body to slide in a vertical direction and having an air suction hole penetrating up and down; An air suction pipe connected to an upper end of the air suction hole of the suction plate and fitted to slide through the pressure plate to slide in the air suction path of the rotating shaft; Characterized in that it comprises a pressure liquid filled in the space sealed by the pressure plate and the adsorption plate.

The auxiliary pressing plate is fixedly coupled to the outer circumferential surface of the rotating shaft, and the freely expandable corrugated pipe is connected to the inside of the corrugated pipe so that the inside of the corrugated pipe is filled with a pressurizing liquid. do.

Pressurized liquid is characterized in that any one of water, press oil, mercury.

The main body is characterized in that the guide ring having a predetermined thickness is installed on the lower edge.

The pressing plate is characterized in that the sealing member is installed on the outer peripheral surface to maintain the airtightness with the inner surface of the mounting space of the main body.

Pressurized plate is characterized in that the sealing member is installed in order to maintain the airtight portion in contact with the air suction pipe.

Adsorption plate is characterized in that the sealing member is installed on the outer peripheral surface to maintain the airtightness with the inner surface of the mounting space of the main body.

Air suction hole of the adsorption plate is characterized in that the lower end is divided into a plurality.

The air suction pipe is formed with a flange on the outer circumferential surface, the air suction path of the rotating shaft is characterized in that the flange guide portion for suppressing the flange is separated from the lower side is formed.

1 is a cross-sectional view schematically showing a conventional CMP apparatus,

2 is a cross-sectional view showing an upper ring of a conventional CMP apparatus,

3 is a cross-sectional view showing an upper ring of the CMP apparatus according to the present invention,

4 is a cross-sectional view taken along line AA ′ of FIG. 3.

<Description of Symbols for Main Parts of Drawings>

100; Upper ring 110; Axis of rotation

111; Air suction 120; main body

121; Mounting space 122; Guide ring

130; Pressing plate 140; Adsorption Plate

141; Air suction hole 150; Air suction pipe

160, 190; Pressurizing liquid 170; Auxiliary Pressure Plate

180; Corrugated pipe

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention.

3 is a cross-sectional view showing an upper ring of the CMP apparatus according to the present invention, Figure 4 is a cross-sectional view taken along the line AA 'of FIG. As shown, the upper ring of the CMP apparatus according to the preferred embodiment of the present invention is rotatably coupled to the upper ring arm 32 and the rotation shaft 110 is formed in the air suction path 111, the inside Mounting space 121 is formed so that the lower side is open, the lower end of the rotating shaft 110 is inserted into the upper side of the mounting space 121 and the main body 120 and the rotating shaft 110 coupled to rotate together with the rotating shaft 110. It is coupled to the lower end of the pressing plate 130 is fitted to slide in the vertical direction to the mounting space 121 of the main body 120, and is fitted to slide in the vertical direction to the lower portion of the mounting space 121 of the main body 120 The adsorption plate 140, through which the air suction hole 141 penetrates up and down, is connected to the upper end of the air suction hole 141 of the adsorption plate 140, and penetrates through the pressure plate 130 to provide a rotation shaft 110. Inserted to slide in the air suction path 111 And a group-introducing tube 150 and the pressing plate 130 and the pressurized liquid 160 for filling in the space enclosed by the suction plate 140.

The rotating shaft 110 is coupled to the upper ring arm 32 with its upper end rotated by an unillustrated cylinder and a driving motor provided on the upper ring arm 32, and moves up and down, and the lower end thereof is the main body 120. Sliding is inserted into the upper side of the mounting space 121 of the) is coupled to the pressure plate 130 fitted in the mounting space 121.

In addition, the rotating shaft 110 forms a protrusion 112 on the outer circumferential surface adjacent to the upper surface of the main body 120 to rotate the main body 120 during rotation, the main body 120 is both sides and the upper side of the protrusion 112. Wrapped around the protrusion 112 is formed on the upper surface is formed to secure a predetermined space so that the protrusion 112 is slid in the vertical direction from the inside.

The main body 120 is inserted into the mounting space 121 up and down to slide the pressing plate 130 and the adsorption plate 140 vertically, respectively, to form a closed space therebetween, and wear on the bottom edge A guide ring 122 having a constant thickness is installed to allow replacement at a time.

The pressing plate 130 is provided with a sealing member 131 such as an O-ring in order to maintain the airtightness with the inner surface of the mounting space 121 of the main body 120 on the outer peripheral surface.

In addition, the pressurizing plate 130 penetrates the air suction pipe 150 connected to the air suction hole 141 of the suction plate 140 at the center thereof, and also maintains airtightness at the air contact pipe 150 to be in contact with the O-ring. The same sealing member 132 is installed.

Adsorption plate 140 is the air suction input generated by the pumping of a vacuum pump (not shown) for supplying a vacuum to the CMP apparatus through the air suction path 111 and the air suction pipe 150 of the rotary shaft 110 By supplying to 141, the wafer W is vacuum-adsorbed to the lower surface.

In addition, the adsorption plate 140 is provided with a sealing member 142 such as an O-ring in order to maintain the airtightness with the inner surface of the mounting space 121 of the main body 120 on the outer peripheral surface.

The air suction hole 141 is preferably formed such that the lower end portion 141a is branched into a plurality of the lower surface of the suction plate 140 at regular intervals.

The air suction pipe 150 is coupled to the upper end of the air suction pipe 141 of the adsorption plate 140, penetrates the pressure plate 130 in a state in which airtight is maintained, and slides in the air suction path 111 of the rotary shaft 110. Combined.

In addition, the air suction pipe 150 has a flange 151 is formed on the outer peripheral surface of the top, guides the flange 151 and the air suction path 111 of the rotary shaft 110 to suppress the flange 151 is separated to the lower side Preferably, the flange guide portion 111a having a diameter larger than the diameter of the air suction passage 111 is formed.

The pressurizing liquid 160 is filled in a space enclosed by the pressing plate 130 and the adsorption plate 140 of the mounting space 121 of the main body 120, and used for applying a load to the conventional wafer W. Although it has a greater viscosity than the compressed air, for example, it is preferably any one of water, press oil, and mercury (Hg).

Meanwhile, the auxiliary pressing plate 170 fixedly coupled to the outer circumferential surface of the rotating shaft 110 and the lower pressing edge of the auxiliary pressing plate 170 and the upper surface edge of the main body 110 are connected to each other so as to be sealed inside, and a freely expandable corrugated pipe And a pressurizing liquid 190 filled in the corrugated pipe 180.

The pressurizing liquid 190 is one of water, press oil, and mercury (Hg), for example, similarly to the pressurizing liquid 160 filled in the space sealed by the pressurizing plate 130 and the adsorption plate 140. desirable.

The upper ring of the CMP apparatus of the present invention having such a structure operates as follows.

The air suction input generated by the pumping of the vacuum pump (not shown) for supplying the vacuum to the CMP apparatus when the wafer W is vacuum-adsorbed to the upper ring 100 is the vacuum suction path 111 and the vacuum suction tube of the rotating shaft 110. The wafer W is vacuum-adsorbed to the lower surface of the suction plate 140 by being supplied to the vacuum suction hole 141 through the 150.

At this time, the lower end portion (141a) of the air suction hole 141 is divided into a plurality of balanced on the lower surface of the adsorption plate 140 at regular intervals so as to suck the air through the air suction hole 141 adsorption plate 140 The vacuum W is allowed to stably balance the wafer W.

When the wafer W is vacuum-adsorbed to the upper ring 100, the upper ring 100 is moved to the polishing pad 21 (shown in FIG. 1) by the upper ring arm 32 and vacuum-adsorbed to the adsorption plate 140. The wafer W is rotated in contact with the polishing pad 21 at a constant pressure.

The rotating shaft 110 presses the pressing plate 130 downward by the upper ring arm 32 so that the pressurizing liquid 160 having a viscosity greater than that of the conventional compressed air for applying the load of the wafer W is absorbed by the adsorption plate 140. By uniformly bringing the wafer W vacuum-adsorbed into the wafer to the polishing pad 21 in a balanced manner, polishing of the wafer W is performed uniformly.

In addition, the pressurizing liquid 190 filled in the corrugated pipe 180 by the auxiliary pressing plate 170 pressurized downward together with the rotating shaft 110 may move the guide ring 122 of the main body 120 around the wafer W. FIG. By crimping to the polishing pad 21 of the polishing pad, the guide ring 122 is used to unfold the polishing pad 21 of the wafer W, thereby preventing the wafer W from being excessively polished at the edge.

The upper ring of the CMP apparatus according to the most preferred embodiment of the present invention uses liquid as a load applying medium to adhere the wafer surface to the polishing pad during polishing so that the viscosity of the liquid adheres to the polishing pad in a balanced manner. Thus, the wafer is uniformly polished, and the polishing is continuously performed without supplying a liquid, which is a load applying medium to the wafer, during the polishing, thereby simplifying maintenance and repair.

As described above, the upper ring of the CMP apparatus according to the present invention uses liquid as a load applying medium for bringing the wafer surface into close contact with the polishing pad so that the surface of the wafer is brought into close contact with the polishing pad by the viscosity of the liquid. The wafer is uniformly polished, and the polishing is continuously performed without supplying a liquid, which is a load applying medium to the wafer, to have a simple structure and easy maintenance and repair.

What has been described above is only one embodiment for carrying out the upper ring of the CMP apparatus according to the present invention, the present invention is not limited to the above embodiment, as claimed in the following claims of the present invention Without departing from the gist of the present invention, one of ordinary skill in the art will have the technical spirit of the present invention to the extent that various modifications can be made.

Claims (9)

The upper ring which vacuum-adsorbs the wafer to the lower side by the pumping of the vacuum pump, and the upper ring arm which is coupled to the upper side of the upper ring and pressurizes the upper ring to the polishing pad at a constant pressure and rotates it to polish the wafer. In the upper ring head of the CMP apparatus, A rotating shaft rotatably coupled to the upper ring arm and having an air suction path connected to the vacuum pump at an inner side thereof; A main body coupled to the lower side of the mounting space, the lower side of the rotating shaft being inserted into the upper side of the mounting space and being rotated together; A pressure plate coupled to a lower end of the rotating shaft and fitted to slide in a vertical direction in a mounting space of the main body; An adsorption plate inserted into the lower end of the mounting space of the main body so as to slide in a vertical direction and having an air suction hole penetrating up and down; An air suction pipe connected to an upper end of an air suction hole of the suction plate and fitted to slide in the air suction path of the rotary shaft through the pressure plate; A pressurizing liquid filled in a space sealed by the pressurizing plate and the suction plate; The upper ring of the CMP device, characterized in that it comprises a. According to claim 1, wherein the auxiliary pressing plate is fixedly coupled to the outer peripheral surface of the rotating shaft, freely stretched corrugated pipe is connected to the inner edge of the lower surface edge of the auxiliary pressing plate and the upper surface of the main body is sealed, the inside of the corrugated pipe The upper ring of the CMP apparatus, characterized in that the liquid for pressurization is filled. The upper ring of claim 1 or 2, wherein the pressurized liquid is any one of press oil, mercury, and water. The upper ring of claim 1 or 2, wherein the main body is provided with a guide ring having a predetermined thickness at a lower edge of the main body. The upper ring of the CMP apparatus according to claim 1, wherein the pressing plate is provided with a sealing member on an outer circumferential surface of the pressing plate to maintain an airtightness with an inner surface of the mounting space of the main body. The upper ring of the CMP apparatus according to claim 1, wherein the pressure plate is provided with a sealing member to maintain airtightness at a portion where the air suction pipe is in contact with the pressing plate. The upper ring of the CMP apparatus according to claim 1, wherein the adsorption plate is provided with a sealing member on an outer circumferential surface thereof to maintain an airtightness with an inner surface of the mounting space of the main body. The upper ring of the CMP apparatus according to claim 1, wherein the air suction holes of the suction plate are branched into a plurality of lower ends. The CMP of claim 1, wherein the air suction pipe has a flange formed on an outer circumferential surface thereof, and the air suction path of the rotating shaft guides the flange, and a flange guide part for preventing the flange from being separated downward is formed. Upper ring of the device.