Komatsu Denshi Kinzoku Kabushiki Kaisha

Komatsu Electronic Metals Co., Ltd.

Sumco Techxiv Corporation

Other

Toshirou Kotooka

Makoto Kamogawa

Yoshiyuki Shimanuki

Tadayuki Hanamoto

Shigeo Morimoto

Hiroshi Monden

Toshiaki Saishoji

Masato Moriya

Hiroshi Inagaki

Shigeki Kawashima

Toshimichi Kubota

Daisuke Ebi

Kentaro Nakamura

Yoshinobu Hiraishi

Kozo Nakamura

Hirotaka Nakajima

Kengo Hayashi

Tadashi Hata

Takashi Yokoyama

Susumu Maeda

Shinya Sadohara

Masashi Nishimura

Kazuyoshi Sakatani

Toshio Hayashida

Toshiaka Saishoji

Shinji Togawa

Kazuhiro Mimura

In a Czochralski (CZ) single crystal puller equipped with a cooler and a thermal insulation member, which are to be disposed in a CZ furnace, smooth recharge and additional charge of material are made possible. Further, elimination of dislocations from a silicon seed crystal by use of the Dash's neck method can be performed smoothly. To these ends, there is provided a CZ single crystal puller, wherein a cooler and a thermal insulation member are immediately moved upward away from a melt surface during recharge or additional charge of material or during elimination of dislocations from a silicon seed crystal by use of the Dash's neck method.

Apparatus for pulling single crystal by CZ method

A method for controlling the temperature gradient on the side surface of a silicon single crystal, the height of a solid-liquid interface, and the oxygen concentration in the longitudinal direction of the silicon single crystal is provided in order to manufacture a defect-free silicon single crystal whose oxygen concentration is controlled to a predetermined value rapidly and stably. By disposing a cylindrical cooler around the silicon single crystal, and adjusting the pulling speed of the silicon single crystal, the rotation speed of a crucible that stores molten silicon and the rotation speed of the silicon single crystal, and the output ratio of a multi-heater separated into at least two in the longitudinal direction of the silicon single crystal disposed around the crucible, the temperature gradient on the side surface, the height of the solid-liquid interface, and the oxygen concentration in the longitudinal direction of the silicon single crystal are controlled.

Method for manufacturing defect-free silicon single crystal

A method for growing a silicon crystal by a Czochralsky method, wherein, let a pulling speed be V (mm/min) and an average value of an in-crystal temperature gradient in a pulling axis direction within a temperature range, a silicon melting point to 1350&#xb0; C., be G (&#xb0; C./mm), V/G ranges from 0.16 to 0.18 mm/&#xb0; C. min between a crystal center position and a crystal outer periphery position, and a ratio G outer/G center of an average value G of an in-crystal temperature gradient in a pulling axis direction within a temperature range, a silicon melting point to 1350&#xb0; C., at a crystal outer surface to that at a crystal center is set to up to 1.10 to thereby obtain a high-quality perfect crystal silicon wafer. Such a perfect crystal silicon wafer, wherein an oxygen concentration is controlled to up to 13&#xd7;10atoms/cm, an initial heat treatment temperature is at least up to 500&#xb0; C. and a temperature is raised at up to 1&#xb0; C./min at least within 700 to 900&#xb0; C., thereby making uniform a wafer radial distribution to an arbitrary oxygen precipitation density level.

Production method for silicon single crystal and production device for single crystal ingot, and heat treating method for silicon crystal wafer

A melt level or the gap between a melt surface and a heat shield is measured accurately irrespective of how the melt surface is. A laser beam from a range-finding unit is reflected by a scanning mirror and projected on a melt surface through an entrance window and a quartz prism in a chamber of a puller. After specular reflection, the beam forms a measurement spot in the bottom of a heat shield and scatters. Part of the scatter, after specular reflection at the melt surface (secondary reflection), passes through the prism, the entrance window and the scanning mirror to the range-finding unit. The range-finding unit carries out triangulation using the distance between a laser source and a photodetector therein, and the angle of incidence and the angle of the received laser beam.

Method and apparatus for measuring melt level

A method for producing a silicon ingot having no defect over a wide range of region with stability and good reproducibility, wherein when a silicon single crystal () is pulled up form a silicon melt (), the shape of a solid-liquid interface () which a boundary between the silicon melt () and the silicon single crystal () and the temperature distribution on the side face () of a single crystal under being pulled up are appropriately controlled.

Method for producing silicon single crystal having no flaw

There are provided a system for manufacturing a single-crystal ingot which is equipped with a cooler for cooling the single-crystal ingot being pulled and is capable of forming a tail without involvement of excessive heating of a crucible, as well as to a method for controlling the system. In a system for manufacturing a single-crystal ingot having a cooler for cooling a single-crystal ingot which is being pulled from molten raw material (called a single-crystal pulled ingot), when a tail of the single-crystal pulled ingot is formed, the cooler is moved away from the solid/melt interface between the single-crystal ingot and the molten raw material, to thereby reduce the power dissipated by the system. In the system, the cooler is moved upward after the end of a product area of the single-crystal ingot has been cooled until it passes through a grown-in defect temperature range.

Method and apparatus for manufacturing single-crystal ingot

A melt level detector is provided for detecting the melt level of a CZ furnace by triangulation. The laser beam ( ) from a laser source ( ) is moved in radial directions of a crucible ( ) in the CZ furnace to find a location where a photodetector system ( ) can receive the reflection ( ) from the melt level ( ), and the laser beam ( ) is fixed at the location. Since the measurements thus take place within an extremely small angular range of the laser beam, the melt level ( ) can be detected with little effect of noise on the melt level ( ) while eliminating complexity of the device.

Method and apparatus for detecting melt level

A device for producing single-crystal ingot, provided with coolers ( ) using a piping system through which cooling water failure caused by water leakage and at the same time to find out conditions for maximizing a production efficiency, the coolers ( ) are disposed at portions of the inner sides of thermal shielding elements ( ) and the lower ends ( ) of cooling pipes are so set as to be positioned up to 150 mm high from the surface ( ) of molten silicon liquid.

Device and method for producing single-crystal ingot

There are provided a CZ system for manufacturing a single-crystal ingot, which produces a perfect crystal with good reproducibility through growth of a single-crystal ingot, as well as a method of manufacturing the single-crystal ingot. A system of manufacturing a single-crystal ingot by pulling a single-crystal ingot from molten raw material by means of a Czochralski technique, the system including measurement means for measuring the distance between the level of molten raw material and the bottom of a heat-shielding member. On the basis of the thus-measured distance, the temperature gradient of area G of the single-crystal pulled silicon ingot is controlled so as to produce a perfect crystal with good reproducibility, by means of controlling any factor for pulling a single-crystal silicon ingot selected from the group comprising the amount of heat applied to silicon melt, the level of silicon melt, and the pull rate of a single-crystal silicon ingot.

System for manufacturing a single-crystal ingot employing czochralski technique, and method of controlling the system

This invention provides a device for manufacturing single crystals provided with an after-cooler that causes an abrupt temperature gradient along the axis of the crystal being lifted. The device according to this invention can further increase the lifting speed of single crystals. The after-cooler (4) is disposed between the single crystal (5) being lifted and the heat-shield plate (1). Both the inner surface facing the single crystal (5) and the outer surface facing the heat-shield plate (1) of the after-cooler have a surface emissivity value larger than 0.6. Furthermore, the after-cooler (4) is made of cooling pipes or cooling jackets, and the surfaces of the after-cooler (4) are treated by oxidizing or nitriding so as to increase their emissivity values.

Device for manufacturing single crystals

An apparatus for fabricating single-crystal silicon easily controlling a temperature gradient based on the Czochralski (CZ) method, and more particularly preventing as-grown defects created in order to obtain high-quality single-crystal silicon. The above-mentioned apparatus includes a first thermal shield member surrounding the pulling single-crystal silicon and a second thermal shield member inside the first thermal shield member, surrounding the pulling single-crystal silicon. The second thermal shield member is fixed on the first thermal shield member by a support located on the external surface of the second thermal shield member and connected to the first thermal shield member. The surroundings of a solid-liquid interface are extremely cooled by using the first thermal shield member, thereby a stable shape of the single-crystal silicon is formed. The temperature gradient of the temperature region of 1000.degree. C..about.1200.degree. C. where the single-crystal silicon passes is decreased by using the second thermal shield member so as to reduce the crystal defect density, thereby obtaining single-crystal silicon having a stronger oxide film voltage breakdown characteristic. If the support length is changed, the second thermal shield member can be adjusted in the upper or lower direction in order to make the expected portion of single-crystal silicon cool slowly.

Apparatus for fabricating single-crystal silicon

An cylindrical after-heater surrounding a single crystal being lifted and a cylindrical heat-retaining cylinder installed between the after-heater and the single crystal are provided above a reversed frustrated heat-shielding sleeve disposed near the melted liquid. The heat history of the single crystal can be controlled by adjusting the output of the after-heater and the location of the heat-retaining cylinder. By such an arrangement, rapid respond to the change of the heat environment in a furnace can be made and control of the temperature gradient of the single crystal can be achieved. The single crystal, throughout the whole length, is maintained in the range of from 1000.degree. C. to 1200.degree. C. for more than one hour during lifting operation.

Apparatus for manufacturing semiconductor single crystals

This invention provides a method and apparatus for fabricating semiconductor single crystals. By using the method of this invention, the temperature gradient of the single crystal being lifted can be easily controlled. The as-grown defect density can be reduced, and it is possible to manufacture high quality semiconductor single crystals with high oxidation-film breakdown strength. A shield cylinder is used for surrounding the semiconductor single crystal 7 being lifted, the shield cylinder is made to be of the telescopic type and consists of a first shield duct 4, a second shield duct 5, a third shield duct 6. A wire 8 wrapping around a wind-up reel 10 is engaged with the third shield duct 6, and the shield cylinder can be driven to extend or retract by rotating the wind-up reel 10. An ascend and descend rod 3 is connected with the first duct 4, and the shield cylinder can be driven to move upward or downward by lifting or lowering the ascend and descend rod 3. The wind-up reel 10 is driven to retract part of the shield cylinder so that the lapped portion of the shield cylinder keeps a predetermined portion of the semiconductor single crystal 7 being lifted warm, and the temperature gradient of the semiconductor single crystal 7 can be reduced when it passes through the zone whose temperature is within a range from 1000.degree. C. to 1200.degree. C.

Growing community of inventors

Kanagawa, Japan

Toshirou Kotooka