Shin-etsu Handotai Co., Ltd.

Other

Super Silicon Crystal Research Institute Corp.

Hiroshi Oishi

Keiichiro Asakawa

Junichi Matsuzaki

Daisuke Nakamata

Shinji Nagatsuka

Shigeru Okubo

Hideo Kudo

Tadahiro Kato

Koji Kitagawa

Akio Ashida

Kenji Kobayashi

Shinnji Shibaoka

Hiroo Unozawa

Hiroshi Kawarai

The invention is directed to a method for slicing an ingot in the form of a wafer by winding a wire around a plurality of grooved rollers and pressing the wire against the ingot while making the wire travel and supplying slicing slurry to the grooved rollers, in which when the ingot is sliced, an amount of displacement of the ingot changing in an axial direction is measured and an amount of axial displacement of the grooved rollers is controlled so as to correspond to the measured amount of axial displacement of the ingot, and thereby, the ingot is sliced while controlling a relative position of the wire relative to an entire length of the ingot changing in the axial direction. As a result, a slicing method and a wire saw apparatus are provided that can perform slicing in such a way that a Bow or a Warp in a wafer obtained by slicing can be reduced, for example, by controlling a slicing path built into an ingot so that, in particular, the slicing path becomes flattened.

Slicing method and wire saw apparatus

A wafer slicing method includes winding a wire around rollers and pressing the wire against an ingot while supplying slurry to the rollers. A previously conducted experiment provides a supply temperature profile of the slurry during the slicing process and the relationship to the axial displacement of the rollers. This relationship is used to implement slurry delivery during the slicing process. The resultant wafers are bowed in a uniform direction. This slicing method provides excellent reproducibility in addition to producing wafers that are bowed in a uniform direction.

Slicing method and method for manufacturing epitaxial wafer

The present invention provides a slicing method comprising winding a wire around a plurality of grooved rollers and pressing the wire against an ingot to be sliced into wafers while supplying a slurry for slicing to the grooved rollers and causing the wire to travel, wherein a supply temperature of the slurry for slicing is controlled, and slicing is performed in such a manner that the supply temperature of the slurry for slicing and a temperature of the ingot become at least 30&#xb0; C. or above at end of slicing the ingot. As a result, there is provided the slicing method that can alleviate precipitous cooling of an ingot in the time close to end of slicing the ingot and thereby suppress production of a nano-topography when slicing the ingot by using a wire saw.

Slicing method

The present invention provides a method of improving nanotopography of a surface of a wafer sliced from an ingot by using a wire saw apparatus, including improving straightness of feed of a work feed table which is included in the wire saw apparatus and used for feeding the ingot to a wire row formed by winding a wire around a plurality of rollers, and also provides a wire saw apparatus for slicing an ingot to manufacture a wafer, including: a wire row formed by winding a wire around a plurality of rollers; a work feed table for holding and feeding the ingot to the wire row; and a linear-motion guide for linearly guiding the work feed table, wherein a component having a wavelength of 20 to 200 mm in straightness of feed of the work feed table satisfies a PV value &#x2266;1.0 &#x3bc;m. As a result, there are provided the method of eliminating slice waviness having periodicity to improve the nanotopography of the surface of the wafer and the wire saw apparatus.

Method of improving nanotopography of surface of wafer and wire saw apparatus

The present invention provides a slicing method comprising winding a wire around a plurality of grooved rollers and pressing the wire against an ingot to be sliced into wafers while supplying a slurry for slicing to the grooved rollers and causing the wire to travel, wherein a cooling speed of the ingot when a slicing depth is equal to or above &#x2154; of a diameter is controlled to perform slicing by supplying a slurry for adjusting an ingot temperature to the ingot independently from the slurry for slicing while controlling a supply temperature only in a period from the moment that the slicing depth of the ingot reaches at least &#x2154; of the diameter to end of slicing. As a result, the slicing method is provided, in which rapid cooling of the ingot in the time close to end of slicing the ingot can be alleviated when a wire saw is used to slice the ingot, and generation of a nano-topography can be thereby suppressed and further high quality wafers having a uniform thickness are obtained by slicing.

The present invention is a static pressure pad for supporting both sides of a raw wafer without contact by a static pressure of a fluid supplied to the both sides of the raw wafer in a double-disc grinding machine for a semiconductor wafer, wherein in patterns of lands to be banks of surrounding pockets formed on a surface side of supporting the raw wafer of the static pressure pad, an outer circumferential land pattern required to support the raw wafer is a concentric circle with respect to a rotation center of the raw wafer, and a land pattern inside the outer circumferential land pattern is a non-concentric circle with respect to the rotation center of the raw wafer and asymmetrical with respect to all the straight lines which bisect the static pressure pad. With this static pressure pad, there is provided the double-disc grinding machine and a double-disc grinding method for the semiconductor wafer, which can minimize a 'middle ring' of average components obtained by averaging a nanotopography of the wafers after the double-disc grinding.

Double-disc grinding machine, static pressure pad, and double-disc grinding method using the same for semiconductor wafer

The present invention provides a method for slicing a silicon single crystal ingot having a plane direction (110) by a wire saw to manufacture a (110) silicon wafer, wherein slicing is performed in such a manner that each angle formed between a traveling direction of a wire in the wire saw and a [&#x2212;112 ] direction and a [1-12] direction in the (110) silicon single crystal ingot or a direction crystallographically equivalent to the directions exceeds 30&#xb0;. As a result, the method for manufacturing the (110) silicon wafer that can suppress occurrence of breaking at the time of slicing and improve a production yield ratio can be provided.

Method of manufacturing (110) silicon wafer

Slurry useful for wire-saw slicing has viscosity adjusted to 400-700 mPa&middot;second at a shear speed of 2/second and of 50-300 mPa&middot;second at a shear speed of 380/second. The viscosity of slurry is measured using a cone and plate type viscometer which can measure viscosity at different shear speeds. Since the slurry sufficiently flows into inner parts of grooves formed in an ingot and consumed for wire-saw slicing due to the viscosity controlled in response to the shear speed, the ingot can be efficiently sliced to wafers or discs.

Slurry useful for wire-saw slicing and evaluation of slurry

A newly proposed wire cleaning apparatus used for removing slurry from a wire, which reciprocatively travels between a slicing chamber and a wiring chamber. The wire cleaning apparatus has a couple of multigrooved guide rollers,rotatably provided at a cover,A slurry receiver,is detachably attached to the cover,A centrifugal force is generated during repeated reciprocative movement of the wire,between the multigrooved guide rollers,and,. Slurry is shaken off from the wire,by the centrifugal force and gathered in the slurry receiver,Removal of the slurry is accelerated by spraying a cleaning liquid W at the same time. Introduction of the cleaning liquid W into the slicing chamber is inhibited by on-off control of the cleaning nozzles,in response to a travelling direction of the wire

Wire cleaning apparatus

An ingot,is sliced to wafers by a wire,which travels around grooved rollers,to,. A tension applied to the wire,is detected by tension sensors,, while vertical displacement of dancer rollers,is detected by position sensors,. At least one of a fluctuation gap of the tension, a fluctuating velocity of the tension, an acceleration of the fluctuation, vertical movement of the dancer rollers,, a velocity of the vertical movement and acceleration of the vertical movement is calculated from the detection results, and compared with a threshold in a calculating circuit,to judge a sign predicting abnormal increase of the tension. When the predicting signal appears, a command signal is outputted from the calculating circuit,to a controller,to stop operation of a wire-sawing machine or to relax the wire,. Since rupture of the wire,is prevented in bud, a wire-sawing machine is efficiently driven for slicing the ingot,with a high productivity.

Wire-sawing machine

If something goes wrong with a wire saw, a personal computer outputs a dial signal to a modem, which dials a calling number of a pager carried by an operator through a telephone system. The sound of the pager notifies the operator of the abnormality of the wire saw even if he or she is not in the vicinity of the wire saw.

Abnormality transmission system for wire saw

A sensor measures a displacement of a sensor, and a control part of a wire saw calculates a sliding load in accordance with the measured displacement and an initial tension of the wire. Then, the control part compares the calculated cutting load with a preset reference value, and controls an ingot feed speed for a drive unit of a workpiece feed table in accordance with the results of the comparison.

Wire saw control method and wire saw

An ingot slicing method and apparatus is disclosed. An ingot is sliced by a wire saw having a wire wound over a plurality of grooved rollers at a predetermined pitch. The ingot is secured to a holder and then pressed onto the wire which is carried along one direction or reciprocatively carried over a plurality of grooved rollers. The holder is shifted along one direction parallel to an axis of the grooved rollers until about a half section of the ingot is sliced. The holder is shifted along an inverse direction during slicing the remainder of the ingot. Thus, a wafer sliced off the ingot has a bowed shape corresponding to a locus of movement of the holder.

Ingot slicing method and apparatus therefor

There is disclosed a method of slicing a workpiece through use of a wire saw. The workpiece is pressed at a predetermined feed rate against a wire which moves from a wire feed side to a wire take-up side and slices the workpiece into wafers while abrasive grain slurry is fed to the press contact portion between the wire and the workpiece. The feed rate of the workpiece is controlled according to the size of abrasive grains in the abrasive grain slurry, such that a decrease in the slicing stock removal stemming from a decrease in the size of abrasive grains during slicing is compensated with an increase in the slicing stock removal effected by decreasing the feed rate of the workpiece. The method can make the thicknesses of sliced wafers uniform to the extent possible.

Method of slicing a workpiece through use of a wire saw, and a wire saw

A wafer 1 has a chamfered edge 2 polished to specular glossiness, and a laser mark for indication of crystal orientation is put on the chamfered edge 2. Another laser mark 4 for indication of specification, production number, identification, etc. may be carved as a bar code on the chamfered edge 2. These marks 3, 4 are carved on the chamfered edge 2 by laser marking which does not put any harmful influences on the wafer 1.

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Annaka, Japan

Hiroshi Oishi