Loading patent…
AssigneesEbara Corporation, Shimadzu Corporation
InventorsYoichi Kobayashi, Shunsuke Nakai, Hitoshi Tsuji, Yasuo Tsukuda, Junki Ishimoto, Kazunari Shinya
Estimating the term…
A polishing state monitoring apparatus measures characteristic values of a surface, being polished, of a workpiece to determine the timing of a polishing end point. The polishing state monitoring apparatus includes a light-emitting unit for applying light from a light source to a surface of a workpiece being polished, a light-receiving unit for receiving reflected light from the surface of the workpiece, a spectroscope unit for dividing the reflected light received by the light-receiving unit into a plurality of light rays having respective wavelengths, and light-receiving elements for accumulating the detected light rays as electrical information. The polishing state monitoring apparatus further includes a spectral data generator for reading the electrical information accumulated by the light-receiving elements and generating spectral data of the reflected light, and a processor for calculating a predetermined characteristic value on the surface of the workpiece based on the spectral data generated by the spectral data generator.
A polishing apparatus comprising:
A polishing apparatus comprising:
A method of polishing a workpiece, the method comprising:
A method of polishing a workpiece, the method comprising:
Dependencies are inferred from the claim text.
Drawings are temporarily unavailable. Open the PDF at USPTO
From the US filing history. Foreign family members aren’t listed.
Measuring or gauging equipment for controlling the feed movement of the grinding tool or work; Arrangements of indicating or measuring…
Control means for lapping machines or devices: devices or means for detecting lapping completion
Machines, devices, or processes for grinding or polishing
Term ended 15 Feb 2024 (estimated)
The present invention relates to an apparatus for monitoring a polishing state of a workpiece, and more particularly to a polishing state monitoring apparatus for measuring characteristic values of a surface, being polished, of a workpiece (object to be polished) such as a semiconductor wafer to determine the timing of a polishing end point (stop of polishing or a change in polishing conditions). The present invention also relates to a polishing apparatus incorporating such a polishing state monitoring apparatus, and a polishing method.
As semiconductor devices have become more highly integrated in recent years, circuit interconnections have become finer and devices to be integrated have been multilayer devices. Therefore, it is necessary to planarize a surface of a semiconductor wafer. It has been customary to remove surface irregularities from the surface of the semiconductor wafer by a chemical mechanical polishing (CMP) process so as to planarize the surface of the semiconductor wafer.
According to the chemical mechanical polishing process, after the semiconductor wafer has been polished for a certain period of time, the polishing needs to be finished at a desired position on the semiconductor wafer. For example, it may be desirable to leave an insulating layer such as SiO2 over a metal interconnection of Cu or Al (such an insulating layer is referred to as an interlayer film because a metal layer will be formed on the insulating layer in a subsequent process). If the semiconductor wafer is polished more than required, then a lower metal film is exposed on the surface. Therefore, the polishing process needs to be finished in order to leave a predetermined thickness of the interlayer film.
FIG. 1 is a schematic view showing an overall arrangement of a polishing apparatus having a polishing state monitoring apparatus according to an embodiment of the present invention;
FIG. 2 is a diagram showing the operation of light-receiving elements in a spectroscope unit in a case where a pulsed light source is used in the polishing state monitoring apparatus shown in FIG. 1;
FIG. 3 is a diagram showing the operation of light-receiving elements in a spectroscope unit in a case where a continuous light source is used in the polishing state monitoring apparatus shown in FIG. 1;
An embodiment of a polishing apparatus according to the present invention will be described in detail below with reference to FIGS. 1 through 16. In FIGS. 1 through 16, identical or corresponding components are denoted by identical reference characters, and will not be described repeatedly.
FIG. 1 is a schematic view showing an overall arrangement of a polishing apparatus according to an embodiment of the present invention. As shown in FIG. 1, the polishing apparatus according to the present embodiment has a polishing table 12 with a polishing pad 10 attached to an upper surface thereof, and a top ring 14 for holding a semiconductor wafer W, which is a workpiece (object to be polished), and pressing the semiconductor wafer W against an upper surface of the polishing pad 10. The upper surface of the polishing pad 10 serves as a polishing surface which is brought in sliding contact with the semiconductor wafer W as the object to be polished. The upper surface of a fixed abrasive plate comprising fine abrasive particles (made of CeO2 or the like) fixed by a binder such as resin or the like may be used as a polishing surface.
The polishing table 12 is coupled to a motor (not shown) disposed therebelow, and can be rotated about its own axis as indicated by the arrow. A polishing liquid supply nozzle 16 is disposed above the polishing table 12 and supplies a polishing liquid Q onto the polishing pad 10.