JPH10151563A - Chemical machine grinding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical machine grinding device capable of reducing dispersion concerning recovery of a pad surface by dressing and precisely and stably recovering the pad surface. SOLUTION: A grinding pad 107 is adhered on an upper surface of a platen 101, and a wafer carrier 111 to hold a wafer 109 to be ground against a pad surface 107a is provided above this polishing pad 107. This wafer carrier 111 is constituted free to make the wafer 109 precisely contact with the pad surface 107a. A dresser part 113 to recover the pad surface 107a is provided on the wafer carrier 111, and this dresser part 113 is constituted to vertically move. A ring shape dresser is provided on a lower part of the dresser part 113. Consequently, it is possible to reduce dispersion concerning recovery of the pad surface by dressing and to precisely and stably recover the pad surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to chemical mechanical polishing (CMP), and more particularly to a dresser for regenerating a polishing pad used for chemical mechanical polishing. The present invention relates to a chemical mechanical polishing apparatus (hereinafter, also referred to as a “CMP apparatus”) in which variation in the relationship is reduced.

[0002]

2. Description of the Related Art Conventionally, in manufacturing a semiconductor device (for example, a multilayer wiring device), a CMP method has been used as one of methods for polishing a generated interlayer insulating film to flatten its surface.

In the CMP method, as the polishing proceeds, the surface roughness (asperity) of the polishing pad decreases, and therefore, the ability to hold a slurry liquid containing an abrasive decreases. As a result, the polishing rate decreases. 2. Description of the Related Art Conventionally, in order to return the roughness of a polishing pad surface to an initial state before polishing and to suppress a decrease in a polishing rate, the pad surface is dressed (dressing) using a dresser portion (dress head).

FIG. 3 (a) is a plan view showing a conventional CMP apparatus, and FIG. 3 (b) is a view 3a-3 shown in FIG. 3 (a).
It is sectional drawing along the a line.

As shown in FIGS. 3A and 3B, this C
The MP device 300 has a platen (polishing platen) 301,
The upper surface of the platen 301 is a circular plane, and is configured to rotate as indicated by an arrow 305 with reference to a rotation axis 303 passing through the center of the circle. A polishing pad 307 is attached to the upper surface of the platen 301. Above the polishing pad 307, a wafer carrier (Wafer carrier) 311 for holding a wafer to be polished (Wafer) 309 so as to face the pad surface 307a is provided. The wafer carrier 311 is configured so that the wafer 309 can be pressed against the pad surface 307a with a predetermined polishing pressure during polishing.

Above the platen 301, a dresser unit 3
13 is provided, and diamond particles are embedded in a contact area (dresser) of the dresser portion 313 with the pad surface 307a of the polishing pad 307. The dresser portion 313 is provided for the purpose of regenerating the surface (pad surface) of the polishing pad 307 because the roughness of the surface decreases as the polishing proceeds as described above.

In the above conventional CMP apparatus, a wafer 309 is mounted on a wafer carrier 311, and the wafer 309 is polished on a pad surface 307 a of a polishing pad 307 while rotating the wafer carrier 311 with respect to a rotating platen 301. The wafer 309 is polished by pressing with pressure. At this time, a slurry liquid (not shown) containing an abrasive is applied to the pad surface 307a of the polishing pad 307.
Supplied to As an abrasive, silica particles are used in many cases in oxide film polishing. And the wafer 30
9 during polishing, the dresser portion 313 is placed on the pad surface 307a, so that the polishing pad 30
The dressing of the seven surfaces is performed to suppress a decrease in the polishing rate.

[0008]

In the above-mentioned conventional CMP apparatus, the wafer carrier 311 and the dresser 313 are separately arranged and separately controlled. In the wafer carrier 311, the polished wafer 309 can be brought into precise contact with the pad surface 307 a, but in the dresser section 313 whose purpose is to recover the pad surface 307 a, the wafer carrier 3
11, the contact surface is not precisely contacted with the pad surface 307a, and the contact surface is quite rough with the pad surface 307a. That is, the dresser unit 313
When the dressing of the pad surface 307a is performed, the pressure for pressing the dresser against the pad surface 307a cannot be adjusted at all, and the dresser portion 313 is simply put on the pad surface 307a by its own weight. Has become. Therefore, the pad surface 3 by the dressing
The recovery of 07a may vary.
As a result, the reproducibility of the polishing rate of the wafer 309 deteriorates due to the variation in the recovery of the pad surface 307a (that is, the polishing rate of the wafer is not constant but changes).
It will be. As a result, the end time of polishing becomes inaccurate, which hinders uniform polishing of the wafer.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above-described circumstances, and has as its object to reduce variations in pad surface recovery due to dressing, and to provide a more accurate and stable pad surface recovery. An object of the present invention is to provide a mechanical polishing device.

[0010]

In order to solve the above-mentioned problems, a chemical mechanical polishing apparatus according to the present invention has a polishing platen on which a polishing pad can be attached on an upper surface, and a polishing plate provided above the polishing platen. A wafer carrier for holding a wafer to be polished and bringing it into precise contact with the surface of the polishing pad, and a dresser portion provided on the wafer carrier for dressing the surface of the polishing pad, It is characterized by having.

A dresser is provided on a wafer carrier capable of bringing a wafer to be polished into precise contact with the surface of a polishing pad. For this reason, the dresser can be accurately brought into contact with the surface of the polishing pad by using the function of precisely bringing the wafer to be polished into contact with the surface of the polishing pad. Therefore, since the dressing accuracy can be improved, the variation in the recovery of the polishing pad surface due to the dressing can be reduced, and the polishing pad surface can be more accurately and stably recovered.

Further, in the chemical mechanical polishing apparatus, it is preferable that the dresser part can be moved up and down. Thereby, the contact pressure between the dresser and the polishing pad surface can be adjusted to a pressure suitable for dressing, and the dressing accuracy can be further improved. further,
By moving the dresser part up and down, only the dresser part can be brought into or out of contact with the polishing pad surface. This makes it possible to perform dressing for recovering the polishing pad surface at the same time as polishing the wafer, and to perform only dressing.

[0013] The chemical mechanical polishing apparatus according to the present invention further comprises a polishing platen to which a polishing pad can be attached on an upper surface, and a wafer carrier provided above the polishing platen for holding a wafer to be polished. A precision contact means for bringing the wafer to be polished held on the wafer carrier into precise contact with the surface of the polishing pad, and provided on the wafer carrier, and a dresser section for dressing the surface of the polishing pad, Up and down movable means for moving the dresser unit up and down, provided on the wafer carrier.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1A is a plan view showing a CMP apparatus according to an embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line 1a-1a shown in FIG. 1A.

As shown in FIGS. 1A and 1B, this C
The MP device 100 has a platen (polishing platen) 101,
The upper surface of the platen 101 is a circular plane, and the platen 101 is configured to rotate as indicated by an arrow 105 with reference to a rotation axis 103 passing through the center of the circle. A polishing pad 107 is attached to an upper surface of the platen 101. Above the polishing pad 107, a wafer carrier (Wafer carrier) 111 for holding a wafer to be polished (Wafer) 109 facing the pad surface 107a is provided. The wafer carrier 111 is provided with precision contact means (not shown) for precisely bringing the wafer 109 into contact with the pad surface 107a.
There is provided a polishing pressure adjusting means (not shown) for pressing against the surface. A dresser portion 113 for restoring the pad surface 107a is provided on a side surface of the bottom cylindrical portion of the wafer carrier 111, and the dresser portion 113 has a cylindrical shape.

FIG. 2 is an enlarged sectional view of the wafer carrier shown in FIG. The dresser unit 113 is arranged in a ring shape around the wafer carrier 111 and is configured to move up and down. That is, the wafer carrier 1
The 11 is provided with a vertically movable means (not shown) capable of moving the dresser section 113 up and down. A ring-shaped dresser 113a is provided below the dresser portion 113, and the pad surface 1 of the dresser 113a is provided.
Diamond particles are buried in the contact portion with 07a.

Next, a method for polishing a wafer using the above-described CMP apparatus will be described with reference to the drawings.

As shown in FIGS. 1A and 1B, first,
The wafer to be polished 109 is mounted on the wafer carrier 111, and the wafer carrier 1 is placed at a position where the polishing surface of the wafer 109 and the pad surface 107a of the polishing pad 107 are in contact with each other.
11 is fixed. The dresser section 113 is moved downward, and fixed at a position where the dresser 113a contacts the pad surface 107a. Next, the platen 101 is rotated in the direction of arrow 105 to supply a slurry liquid (not shown) containing an abrasive to the pad surface 107 a of the polishing pad 107.

Thereafter, using the polishing pressure adjusting means,
The wafer 109 held by the wafer carrier 111 is pressed against the pad surface 107a with a predetermined polishing pressure. At the same time, the dresser 113a is precisely brought into contact with the pad surface 107a by using the mechanism for vertically moving the dresser portion 113 and the above-mentioned polishing pressure adjusting means, and the pressure of this contact is adjusted to one suitable for dressing. I do. next,
After a predetermined polishing time has elapsed, polishing of the wafer 109 is terminated.

According to the above embodiment, the dresser portion 113 is provided in a ring shape around the wafer carrier 111, and the dresser portion 113 is configured to be movable up and down. For this reason, when dressing the polishing pad 107 by the dresser unit 113, using the precision contact means for precisely contacting the wafer with the pad surface,
The dresser 113a and the pad surface 107a can be brought into precise contact with each other. At the same time, dresser 113a
The contact pressure between the pad and the pad surface 107a can be adjusted to a pressure suitable for dressing. Therefore, the accuracy of the dressing can be improved, so that the variation in the recovery of the pad surface 107a due to the dressing can be reduced, and a more accurate and stable pad surface 107 can be obtained.
a can be recovered. Thereby, the pad surface 107a
The variation in the polishing rate associated with the variation in dressing can be suppressed. That is, deterioration of the reproducibility of the polishing rate of the wafer 109 can be prevented, the polishing rate of the wafer 109 can be kept constant from the start of polishing to the end of polishing, and the wafer 109 can be more uniformly polished.

Further, a dresser portion 113 for restoring the pad surface 107a is incorporated in the wafer carrier 111, and the dresser portion 113 is configured to be movable up and down.
07a can be applied or not applied. Therefore, in this CMP apparatus 100, the wafer 109
In addition to performing so-called concurrent dressing, in which dressing for recovery of the pad surface 107a is performed at the same time as polishing, the dressing is performed only after the wafer 109 is polished, and then the wafer 109 is polished again. , So-called interval dressing is also possible.

Further, by incorporating the dresser section 113 into the wafer carrier 111, polishing and dressing of the wafer 109 can be performed by one carrier (wafer carrier 111). Therefore, the cost of the polishing apparatus can be reduced.

[0023]

As described above, according to the present invention,
A dresser is provided on a wafer carrier capable of bringing a wafer to be polished into precise contact with the surface of a polishing pad. Therefore, it is possible to provide a chemical mechanical polishing apparatus capable of reducing variation in pad surface recovery due to dressing and recovering the pad surface more accurately and stably.

[Brief description of the drawings]

FIG. 1A is a plan view showing a CMP apparatus according to an embodiment of the present invention, and FIG.
It is sectional drawing along the 1a-1a line shown to (a).

FIG. 2 is an enlarged sectional view of the wafer carrier shown in FIG. 1 (b).

FIG. 3A is a plan view showing a conventional CMP apparatus, and FIG. 3B is a cross-sectional view taken along line 3a-3a shown in FIG. 3A.

[Explanation of symbols]

100: CMP apparatus (chemical mechanical polishing apparatus), 101: platen (polishing platen), 103: rotating shaft, 105: arrow,
107: polishing pad, 107a: pad surface, 109: wafer to be polished (Wafer), 111: wafer carrier (W)
afer carrier), 113: dresser portion, 113a: dresser, 300: CMP device, 301: platen (polishing platen), 303: rotating shaft, 305: arrow, 307: polishing pad, 307a: pad surface, 309: polishing target Wafer, 311 ... Wafer carr
ier), 313 ... Dresser part.

Claims (3)

[Claims] 1. A polishing surface plate to which a polishing pad can be attached on an upper surface; and a polishing surface plate provided above the polishing surface surface for holding a wafer to be polished and bringing it into precise contact with the surface of the polishing pad. A chemical mechanical polishing apparatus comprising: a wafer carrier; and a dresser unit provided on the wafer carrier for dressing a surface of the polishing pad. 2. The chemical mechanical polishing apparatus according to claim 1, wherein said dresser portion is movable up and down. 3. A polishing platen on which a polishing pad can be attached on an upper surface, a wafer carrier provided above the polishing platen for holding a wafer to be polished, and a polishing platen held on the wafer carrier. A precision contact means for precisely bringing the wafer into contact with the surface of the polishing pad; a dresser section provided on the wafer carrier for dressing the surface of the polishing pad; and the dresser provided on the wafer carrier. And a vertically movable means for moving a part up and down.