JP3364709B2 - Work removal method in polishing machine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing a workpiece, which is a semiconductor wafer serving as a substrate, in a manufacturing process of a super LSI or the like from a base plate after polishing, and further relates to a method for removing the workpiece. More specifically, the present invention relates to a method for safely and securely removing a semiconductor wafer, which is a brittle, ultrathin, and enlarged work piece, from a base plate without damaging the work. BACKGROUND OF THE INVENTION Semiconductor-type wafers of this type according to the present invention include electronic devices such as computers,
It is used for integrated circuits such as OA equipment, and its development is progressing day by day. Further thinning with the miniaturization of the equipment itself, further diameter enlargement from the viewpoint of productivity, and yield From the standpoint of quality, there has been a demand for even higher precision quality. In addition, these semiconductor wafer devices are:
With the increase in density and the degree of integration, the production of ultra LSI (ULSI) of 64 megabytes or more has become necessary, and in recent years, ultra LSI of 256 megabytes or 1 gigabyte has been developed. On the surface of these semiconductor devices, a wiring layer (metal film), an insulating film (oxide film or the like) or a polysilicon film (semiconductor film) is formed as a multilayer film.
In other words, the LSI has a structure equivalent to a two-story or three-story structure for a one-story LSI, and requires polishing of each layer in the manufacturing process with ultra-high precision flatness and mirror accuracy. And Conventionally, a base plate for holding a work such as a polishing apparatus or the like vacuum-adheres and grinds the work, releases the vacuum suction after processing, and reverses the air to remove the semiconductor wafer. Although removed, a porous ceramic or a plate with a number of small holes perforated on the base plate must be used, and further, such devices must be attached to maintain the vacuum,
We have increased the cost of the polishing equipment, so for this purpose, a soft plate is laminated on the base plate, the work is filled with water on the soft plate, and removed using a removal jig such as tweezers, or applied with a water gun. It was removed by spraying water. [0006] However, when the work is removed by using a removal jig such as tweezers, the work is often damaged because the tip of the tweezers of the soft plate and the work is inserted. In the case of removing by applying a water gun, the removal has to be done manually, which is inefficient. SUMMARY OF THE INVENTION The present invention provides a polishing plate fixed to one rotating shaft, a base plate facing the polishing plate and fixed to the other rotating shaft, and a soft plate adhered to the base plate. The plate, the control ring provided around the outer periphery of the soft plate, the slit carved on the inner peripheral surface of the control ring, the liquid ejection mechanism arranged near the slit, and the water attached to the soft plate inside the control ring Work that has been completed. According to the present invention, there is provided a method for removing a work after being polished by being pressed between a polishing plate and a soft plate, and capable of ejecting a liquid to a slit formed in a control ring. Position the injection port of the liquid injection mechanism at
While rotating the control ring by rotating the rotating shaft to which the base plate is fixed, the liquid such as pure water is ejected from the injection port between the slit work and the soft plate and removed, and the work Since the interfacial tension is broken by the liquid, it can be safely and easily removed without damaging the work. Accordingly, an object of the present invention is to use a soft plate as a base plate of a polishing apparatus, provide a slit on an inner peripheral surface of a control ring, and inject a liquid into the slit while rotating the base plate. It is intended to provide a detaching method that can be easily automated for removal and that can be removed without contact, so that there is no damage to the workpiece, and it is possible to cope with ultra-thin, large diameter, ultra-high precision quality. It is the purpose. Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic explanatory view of a polishing apparatus according to the present invention before a method for removing a workpiece is performed, and FIG. 2 is a perspective view of a polishing apparatus according to an embodiment of the present invention. FIG. 3 is an explanatory view of a main part of a base plate for explaining a next embodiment of a method of removing a work in the polishing apparatus of the present invention. The present invention relates to a method of removing a workpiece W, which is a semiconductor wafer serving as a substrate in a manufacturing process of a super LSI or the like, from a base plate 2 after polishing, and more particularly, to a brittle, ultra-thin, and enlarged diameter. The present invention relates to a method for safely and securely removing a semiconductor wafer, which is a structured work W, from a base plate 2, and a polishing plate 1 fixed to one rotating shaft, and a polishing plate 1 facing the polishing plate 1 and being attached to the other rotating shaft. A fixed base plate 2, a soft plate 3 adhered to the base plate 2, a control ring 4 provided around the outer periphery of the soft plate 3 with the top surface slightly lower than the polished surface of the work W, A slit 4a formed on the inner peripheral surface of the control ring 4, a liquid ejecting mechanism 5 disposed near the slit 4a, A method of removing a workpiece W after being polished by being sandwiched between the polishing plate 1 and the soft plate 3 and comprising a flat work W adhered to a soft plate 3 with water. The ejection port 5a of the liquid ejecting mechanism 5 is positioned so that the liquid can be ejected to the slit 4a of the ring 4, and the rotation axis to which the base plate 2 is fixed is rotated to rotate the control ring 4 while the liquid is ejected from the ejection port 5a. And remove it. The workpiece W to be removed by the removal method in the polishing apparatus of the present invention is a semiconductor wafer, and is polished after grinding the semiconductor wafer, and is formed on one surface by a photolithography method, an epitaxial growth method, an aluminum deposition method, or the like. To form an insulating film, a wiring layer, a polysilicon film, etc.,
Further, in the super LSI, these steps are repeated and laminated, and when forming each layer, it is a removal method capable of coping with ultra-high precision flat processing and mirror finishing each time. That is, the embodiment of the present invention will be described with reference to a polishing machine which is a polishing apparatus. The polishing machine has a polishing cloth (not shown) made of non-woven fabric, natural or artificial leather or the like adhered thereto, and is rotated by one driving source. A polishing plate 1 that is fixed to a rotating shaft to be rotated and rotates;
The polishing plate 1 comprises a base plate 2 made of alumina ceramic or the like fixed to a rotating shaft which faces the polishing plate 1 and holds the work W and is rotated by the other drive source. A soft plate 3 made of a soft member such as a silicone resin is bonded to the base plate 2 with an adhesive,
A control ring 4 is adhered to the outer periphery of the soft plate 3 so as to enclose the work W to be filled with water later,
The top surface of the control ring 4 is provided slightly lower than the polished surface of the work W and does not contact when the polished surface of the work W and the polishing cloth are in a parallel state. In other words, it is possible to prevent the edge of the work W being polished, particularly only the edge, from being sharply polished. In the control ring 4 of the present invention, slits 4a are formed in the inner peripheral surface and at least at one place. In the drawings of the embodiment, about two places are provided, but about ten places are provided. The shape and number of the slits 4a are not particularly limited as long as the slits 4a are formed on the inner peripheral surface. In the embodiment shown in FIG. 2, an ejection port 5a of a liquid ejection mechanism 5 connected to a pump or the like is provided near the slit 4a.
In the next embodiment shown in FIG. 3, a work receiving surface facing the work is provided with a liquid ejecting mechanism 5, and a plurality of ejecting ports 5 a are provided above the liquid ejecting mechanism 5, and pure liquid is supplied from the ejecting ports 5 a. Water is injected into the slit 4 a of the control ring 4. Next, the work W is mounted on the control ring 4.
A non-polished surface is affixed to the soft plate 3 with a liquid such as pure water, and is polished with a polishing cloth stretched on the polishing plate 1 to polish a polished surface such as an insulating film. It is. In the method of removing a work according to the present invention, in the polishing apparatus configured as described above, after the work W is polished, the base plate 2 and the polishing plate 1 are separated from each other.
After that, the injection port 5 of the liquid injection mechanism 5 that injects pure water or the like.
a, the soft plate 3 adhered to the base plate 2, the control ring 4, and the work W are rotated together by rotating the rotary shaft to which the base plate 2 is fixed, by positioning the a to be able to be sprayed on the slit 4a of the control ring 4. It is. In this state, the injection port 5a of the liquid injection mechanism 5
, A liquid such as pure water is continuously jetted to the slit 4a, and the liquid easily penetrates between the work W and the soft plate 3 from the slit 4a, so that the soft plate 3 and the work W Between them, it is possible to destroy the interfacial tension of the sticking surface due to a liquid such as pure water. That is, after the workpiece W is polished, the ejection port 5a of the liquid ejection mechanism 5 is positioned so as to be able to eject the liquid to the slit 4a of the control ring 4 without stopping the rotation of the base plate 2, and the liquid is ejected. W
Is to remove it. As described above, the present invention can be applied to the flatness accuracy after polishing a brittle ultra-thin and large-diameter semiconductor wafer which is a work in the process of manufacturing an VLSI, and to the mirror finishing. It can be removed without obstruction, and the workpiece can be easily adhered to the base plate on which the soft plate is adhered with pure water, and easily and easily by jetting a water flow to the slit while rotating the control ring. The work can be removed in a short time, which saves time.It enables automation and prevents the work from drying.In addition, there is no danger of damaging the work because it is removed without contact. The contribution is immeasurable and has a very significant effect.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic explanatory view of a polishing apparatus according to the present invention before a method of removing a work is performed. FIG. 2 is an explanatory view of a main part of a base plate for explaining an embodiment of a method of removing a work in the polishing apparatus of the present invention. FIG. 3 is an explanatory view of a main part of a base plate for explaining a next embodiment of a method of removing a work in the polishing apparatus of the present invention. [Description of Signs] W Work 1 Polishing Plate 2 Base Plate 3 Soft Plate 4 Control Ring 4a Slit 5 Liquid Injection Mechanism 5a Injection Port

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Junichi Yamashita One stock at 555 Nakanoya, Annaka City, Gunma Prefecture Inside the Super Silicon Laboratories (72) Inventor Kenro Hayashi One stock at 555 Nakanoya, Annaka City, Gunma Prefecture Inside the Super Silicon Research Laboratories (72) Inventor Kimiyuki Kawasoe One of 555 Nakanotani, Annaka-shi, Gunma Prefecture Inside the Super Silicon Research Laboratories (56) References JP-A-8-229807 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) H01L 21/304

Claims (1)

(57) Claims: 1. A polishing plate fixed to one rotating shaft, a base plate facing the polishing plate and fixed to the other rotating shaft, and a soft plate adhered to the base plate. A plate, a control ring provided on the outer periphery of the soft plate with the top surface slightly lower than the polished surface of the work, a slit formed in the inner peripheral surface of the control ring, and a control ring disposed in the vicinity of the slit. Removal of the work after being polished by being sandwiched between the polishing plate and the soft plate, the work being composed of a liquid ejecting mechanism provided and a flat plate-like work attached to a soft plate in the control ring with water. A method, comprising: locating an ejection port of a liquid ejection mechanism such that a liquid can be ejected to a slit of the control ring, and rotating a rotation shaft to which the base plate is fixed. Removal method of the work in the polishing apparatus characterized by removing by a liquid is injected from the injection port while rotating the control ring by Rukoto.