Tokyo Seimitsu Co., Ltd.

Minoru Numoto

Takao Inaba

Kenji Sakai

Manabu Satoh

Hisashi Terashita

Takashi Fujita

Masaaki Oguri

Satomi Michiya

Hirohiko Izumi

Tsutomu Kanzaki

Mikhail Tuzov

Shigeyuki Honma

A wafer polisher, wherein a retainer ring () is installed in a wafer holding head (), a protective sheet material () is disposed inside the retainer ring (), and a wafer (W) is pressed against a polishing pad () through the protective sheet material () for polishing, whereby the protective sheet material () can be disposed without causing wrinkles on the inner peripheral part of the retainer ring ().

Wafer polisher

The wafer polishing apparatus enables the control of proper polishing pressure, so that the quality of wafers can be maintained high. A wafer holding head is composed of a carrier for pressing the wafer against a polishing pad, a retainer ring at the circumference of the carrier, and a holding head body. The holding head body includes a carrier pressing device having an air bag of which pressing surface area is 50% or smaller of the area of the wafer, and the pressing force from the carrier pressing device is transmitted to the carrier.

Wafer polishing apparatus

A rotation force of a drive shaft is transmitted from a drive plate to an intermediate plate through a first pin, and a rotation force of the intermediate plate is transmitted to a carrier through a second pin. The rotation force of the drive shaft is transmitted to the carrier through an Oldham's coupling mechanism; thereby, a wafer polishing apparatus can always rotate the carrier in a stable condition even though a wafer receives a friction force in side directions from a polishing pad because no twisting force is applied to the drive shaft.

Wafer polishing apparatus utilizing an Oldham's coupling mechanism for the wafer carrier

In the wafer polishing apparatus for pressing a wafer against a polishing pad with an air bag, which is provided to a carrier, pressing area regulating members are attached to the bottom face of the carrier, whereby areas for pressing the wafer with the air bag are regulated. The pressing area regulating members are prepared in order to regulate different areas to be pressed. The areas for pressing the wafer with the air bag can be changed by replacing the pressing area regulating members when suitable.

A step part is formed on a face of a retainer ring that contacts with a polishing pad so that a wavily deformed part of the polishing pad enters the step part. The step part is formed like a ring at the inside of the face which actually contacts with the polishing pad. Moreover, a height of the step part is smaller than a thickness of a wafer so that a top face of the step part does not contact with the polishing pad and the wafer does not enter the step part. Further, a width of the step part is set so that the wavily deformed part of the polishing pad can enter the step part.

A polishing head of a polishing apparatus of this invention has a structure in which an air blast port is formed in a lower surface of a carrier and an upper outer peripheral portion of the carrier is so formed as to protrude in a diametric direction, and is placed on a retainer ring to thereby form a seal portion The retainer ring clamps a peripheral edge of a rubber sheet in such a form as to cover the carrier. Consequently, an air chamber is formed between the carrier lower surface and the rubber sheet, and an air pressure of this air chamber pushes a wafer W to a polishing cloth

Structure of polishing head of polishing apparatus

In the wafer polishing device, a retainer ring can be attached and detached with ease. Under a retainer ring attaching part disposed on a head body, a retainer ring is attached with a snap ring. The snap ring is divided into two. An upper projection part and a lower projection part are formed on the inner periphery of the snap ring. The upper projection part is fitted to an upper groove formed on the outer periphery of the retainer ring attaching part, and the lower projection part is fitted to a lower groove formed on the outer periphery of the retainer ring. In attachment, the retainer ring is connected to the lower part of the retainer ring attaching part, and the snap ring is placed on the outer periphery of the joint.

Wafer polishing device

An apparatus for polishing wafers in which a first pushing means for imparting a pushing force to a carrier is arranged along the outer peripheral portion under the lower surface of a head body and a second pushing means for imparting a pushing force to a retainer ring is arranged at a central portion under the lower surface of the head body. The first and second pushing means are formed of air bags and

Apparatus for polishing wafers

The present invention provides a wafer polishing apparatus capable of controlling the polishing quantity accurately. The wafer polishing apparatus comprises a rotatable polishing stool with a polishing cloth, a carrier for bringing a wafer into contact with the polishing cloth under a predetermined pressure, a pad arranged around the wafer in such a manner as to contact the polishing cloth under a predetermined pressure, a detector for detecting the change of the relative positions of the back of the wafer or the carrier and the pad, and a control unit for controlling the polishing operation in accordance with the polishing quantity computed from the detection signal of the detector, wherein an operating unit includes a sampling unit ( ) for sampling the detection signal of the detector with such a sampling period that the number of times sampled per rotation of the polishing stool is plural, a moving average calculating unit ( ) for calculating the moving average data by averaging the sampling data in the number equal to an integer multiple of the number of times sampled per rotation, and a polishing quantity computing unit ( ) for computing the polishing quantity from the moving average data.

Wafer grinder and method of detecting grinding amount

Sensors detect a stock removal of a wafer during polishing, and a CPU calculates the stock removal in accordance with information from the sensors. The CPU compares the actual stock removal detected by the sensors and a model stock removal stored in RAM, and determines timings for dressing and replacing said polishing pad in accordance with a difference between the actual stock removal and the model stock removal. The determination results are shown on a display.

A CMP machine of the invention includes first and second polishing bases and first and second wafer holding heads and a wafer loading unit a wafer unloading unit first and second head rotating mechanism rotating the first and second wafer holding heads so as to position then above the first and second polishing bases, wafer loading unit, or wafer unloading unit, a first transportation mechanism transporting an unpolished wafer to the wafer loading unit, and a second transportation mechanism, transporting a polished wafer from the wafer unloading unit. The first and second polishing bases are located mutually adjacently, the wafer loading unit and wafer unloading unit are located mutually adjacently, the first polishing base and wafer loading unit are located diagonally, the second polishing base and wafer unloading unit are located diagonally. Owing to this structure, transportation of a wafer to the wafer loading unit and transportation of a wafer from the wafer unloading unit are achieved by the different transportation mechanisms. This leads to a minimized adhesion of dust to an unpolished wafer.

Wafer polishing machine

The present invention is a wafer polishing apparatus with a device that detects the polishing end according to a change in rotation resistance of a wafer during polishing. The wafer polishing apparatus comprises a head body and a carrier which are connected with each other by a connecting bar which is provided with a strain gage, and determines strain in a horizontal direction of the connecting bar by the strain gage so as to determine a rotation torque of the carrier, whereby accurately detects the polishing end. Since a retainer ring is mounted to the outer periphery of the carrier via an O ring, the impact at contacting of the wafer with the retainer ring can be absorbed by the O ring, thus the wafer is prevented from damage. Because the retainer ring is mounted to the carrier without a gap, the outer periphery of the wafer is enclosed by the retainer ring, and the wafer can be polished in a state where its center is held on the central axis of the carrier. Therefore, the polishing precision of the wafer can be improved.

According to the present invention, a floating mechanism of a load stage floats positioned wafers in concave parts, and then, the chucks hold the wafers by suction. Therefore, the chucks can easily hold the centered wafers.

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Mitaka, Japan

Minoru Numoto