Sumco Corporation

Sumitomo Mitsubishi Silicon Corporation

Ken Hamada

Keiichi Takanashi

Shuichi Inami

Tsuyoshi Nakamura

Nobumitsu Takase

Hiroaki Taguchi

Yasuhiro Kogure

Hiroki Murakami

Takashi Atami

Kazuyuki Egashira

Tokuji Maeda

Takuya Yotsui

A silicon single crystal manufacturing method in which the distance between the heat shield and the melt level of the melt can be regulated in a high precision. The real image includes at least the circular opening of the heat shield provided in such a way that the heat shield covers a part of the melt level of the silicon melt. The mirror image is a reflected image of the heat shield on the surface of the silicon melt. Based on the distance between the obtained real image and the mirror image, the melt level position of the silicon melt is computed, and the distance between the heat shield and the melt level position is regulated.

Silicon single crystal manufacturing method

After melting raw materials, a distance between a raw material melt surface and a heat-shielding member disposed so as to face to the melt surface is adjusted based on temporal changes in chamber inside conditions, such as the heater temperature at the time of completion of the seed crystal equilibration operation carried out after completion of the raw material melting procedure and/or lag time required for completion of the seed crystal equilibration operation following completion of the raw material melting procedure. As a result, single crystals can be produced efficiently and in high yield, and further, by controlling the crystal interior temperature gradient by modifying the distance between the melt surface and the heat-shielding member, it becomes possible to control the ratio V/G (V:pulling speed, G:crystal interior temperature gradient) to thereby produce single crystals free of crystal defects such as COPs and/or dislocation clusters.

Method of producing single crystal

Disclosed herein is a method for manufacturing a single crystal, the method includes: photographing an image of a boundary portion between the single crystal and a melt by a camera during a single crystal pull-up process according to a Czochralski method; comparing at least one pixel included in a left side region with respect to an extension line of a pull-up shaft of the single crystal and at least one pixel included in a right side region with respect to the extension line; and determining an abnormality in a luminance distribution of the image from a result of the comparing.

Method and apparatus for manufacturing single crystal

A manufacturing method of single crystal is provided with a melting process for dissolving raw material in a crucible and a pulling-up process of a single crystal from a melt by the Czochralski method. The pulling-up process includes detecting an edge line of a fusion ring, determining an approximated curve of the edge line by approximating the edge line of the fusion ring by an even function, eliminating constituent pixels of the fusion ring from the image of the fusion ring as noise, the constituent pixels being positioned on the side of the melt relative to the approximated curve and the constituent pixels of the fusion ring and a deviation between the constituent pixels and the approximated curve being a predetermined number of pixels, and calculating the center position of the single crystal from the edge line of the fusion ring from which the noise has been eliminated.

Method of manufacturing single crystal

A method of producing a silicon single crystal is provided. The method may include taking a real image of a heat shield including a circular opening and a mirror image of the heat shield reflected on a surface of the silicon melt, measuring a spacing between the real image and the mirror image, calculating a position of the surface of the silicon melt, taking an image of a bright zone that appears in a vicinity of an interface between the silicon melt and the silicon single crystal, calculating a position of the surface of the silicon melt based on a center position of the silicon single crystal determined from the image of the bright zone, and controlling the position of the surface of the silicon melt during a pulling of the silicon single crystal while referring to data of the calculated positions of the surface of the silicon melt.

Method of producing silicon single crystal

The distance between the heat shield and the melt level of the melt can be regulated in a high precision. The real image includes at least the circular opening of the heat shield provided in such a way that the heat shield covers a part of the melt level of the silicon melt. The mirror image is a reflected image of the heat shield on the surface of the silicon melt. Based on the distance between the obtained real image and the mirror image, the melt level position of the silicon melt is computed, and the distance between the heat shield and the melt level position is regulated.

Silicon single crystal manufacturing apparatus and silicon single crystal manufacturing method

An apparatus of producing a silicon single crystal including: an imaging device; a heat shield that has a circular opening; a first operation unit that operates the imaging device and takes a real image of the heat shield and a mirror image of the heat shield reflected on a surface of the silicon melt, measures a spacing between the real image and the mirror image, and calculates a position of a melt-surface; a second operating unit that operates the imaging device and takes an image of a bright-zone in the vicinity of the solid-liquid interface, and calculates a position of the melt-surface based on the image of the bright zone; and a controlling unit that refers a data of the position of the silicon melt obtained by the first operation unit and the second operation unit, and controls the position of the silicon melt.

Apparatus of producing silicon single crystal and method of producing silicon single crystal

A single crystal pulling apparatus comprises: a chamber; a crucible disposed within the chamber for containing a melt; a water-cooling means disposed within the chamber in such a manner as surrounding a single crystal pulled up from the melt in the crucible; water piping for feeding cooling water to and discharging the same from the water-cooling means; and supporting arms connected to the chamber for supporting the water-cooling means, wherein the supporting arms are disposed between the single crystal and the water piping. According to this configuration, the supporting arms can prevent the water piping from being damaged in the event of fall and collapse of the single crystal due to failure of the seed neck portion or in the event of rupture of the single crystal due to thermal stress, for instance.

Single crystal pulling apparatus

When pulling and growing a single crystal from a raw material melt by the Czochralski method, a boundary between the single crystal and the raw material melt is imaged by an optical sensor, and also the weight of the single crystal is measured by a weight sensor, a diameter value of the single crystal is calculated on the basis of first measured values of the diameter of the single crystal derived from image data captured by the optical sensor and second measured values of the diameter of the single crystal derived from weight data captured by the weight sensor, and a pulling rate of the single crystal and the temperature of the raw material melt are adjusted on the basis of the calculated diameter value to thereby control the diameter of the single crystal, and thus it is possible to accurately measure the diameter of a growing single crystal.

Method of controlling single crystal diameter

In a method for growing a silicon single crystal, a silicon single crystal is grown by the Czochralski method to have an oxygen concentration of 12&#xd7;10to 18&#xd7;10atoms/cmon ASTM-F121 1979. A mixed gas of an inert gas and a gaseous substance containing hydrogen atoms is used as an atmospheric gas for growing the single crystal. A temperature of the silicon single crystal is controlled during the growth of the crystal such that the ratio Gc/Ge of an axial thermal gradient Gc at the central portion of the crystal between its melting point and its temperature of 1350&#xb0; C. to an axial thermal gradient Ge at the periphery of the crystal between its melting point and its temperature of 1350&#xb0; C. is 1.1 to 1.4. The axial thermal gradient Gc at the central portion of the crystal is 3.0 to 3.5&#xb0; C./mm.

Method for growing silicon single crystal and method for manufacturing silicon wafer

A silicon single crystal is grown using the Czochralski method. During the crystal growth, a thermal stress is applied to at least a portion of the silicon single crystal. A gaseous substance containing hydrogen atoms is used as an atmospheric gas for growing the crystal.

Method for growing silicon single crystal

This method for producing silicon single crystals includes: growing a silicon single crystal by the Czochralski method while cooling at least part of the silicon single crystal under growth with a cooling member which circumferentially surrounds the silicon single crystal and has an inner contour that is coaxial with a pull axis, wherein an ambient gas in which the silicon single crystal is grown includes a hydrogen-atom-containing substance in gaseous form. This silicon single crystal is produced by the above method.

Method for producing silicon single crystals and silicon single crystal produced thereby

An apparatus is used to pull a single crystal, wherein a flow of an inert gas to the single crystal to be grown, a pressure in an apparatus body, and a temperature environment are always kept constant by keeping a melt level at a prescribed position in spite of changes in volume of a quartz crucible between batches and thermal deformation of the quartz crucible, so that high quality single crystals can be pulled. The apparatus has a reference reflector arranged inside an apparatus body, a level position measuring unit to measure an actual level position by detecting a mirror image position of the reference reflector reflected in the melt surface using a one-dimensional CCD camera arranged outside the apparatus body, a crucible ascent speed adjustment value calculating unit to calculate an adjustment value of the crucible ascent speed based on an output from the level position measuring unit, an adjustment value adding unit to add the adjustment value to the crucible ascent speed, and a level position controlling unit to control the level position in the crucible by controlling a motor for crucible lifting based on an output from the adjustment value adding means to control the crucible ascent speed.

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Tokyo, Japan

Ken Hamada