Shin-Etsu Handotai Co., Ltd.

Kosei Sugawara

Ryoji Hoshi

Tomohiko Ohta

Hiroyuki Kamada

Kiyotaka Takano

Atsushi Iwasaki

Masahiko Urano

Yuuichi Miyahara

Masanori Takazawa

Wataru Yajima

Toshiro Shimada

Takahide Onai

A single-crystal pulling apparatus includes: a pulling furnace having a heater and crucible; and a magnetic field generation device having superconducting coils, the device having four of the superconducting coils, two of the superconducting coils are in each of two regions divided by a cross section that includes an X axis being a direction of magnetic force lines at the central axis in the horizontal plane including all the coil axes of the four superconducting coils, and includes the pulling furnace central axis having line symmetry about the cross section, the four superconducting coils are all arranged so that the coil axes have an angle of more than −30° and less than 30° relative to a Y axis, the direction of the magnetic force lines thereof have line symmetry about the cross section, and in each of the regions, the two superconducting coils generate magnetic force lines in opposite directions.

Single-crystal pulling apparatus and single-crystal pulling method

A single-crystal pulling apparatus including: a pulling furnace having a central axis; and a magnetic field generation device arranged around the pulling furnace and having superconducting coils, the apparatus applying a horizontal magnetic field to the molten semiconductor raw material, two coil axes in the two pairs of the superconducting coils are included in a single horizontal plane, and when a direction of lines of magnetic force at the central axis of the pulling furnace in the horizontal plane is determined as an X axis, a center angle α having the X axis between the two coil axes is 100 degrees or more and 120 degrees or less. This makes it possible to reduce the height of the coils, to raise the magnetic field center close to the melt surface of the semiconductor raw material, and to obtain a single crystal having a lower oxygen concentration than conventional single crystals.

Single-crystal pulling apparatus with saddle-shaped superconducting coils and single-crystal pulling method

A method for producing a silicon single crystal, wherein a silicon nitride powder is introduced into a raw material before start of melting and the silicon single crystal doped with nitrogen is pulled by Czochralski method, wherein nitrogen doping is performed while an upper limit amount of usable silicon nitride powder is limited based on an amount of carbon impurities contained in the silicon nitride powder so that a carbon concentration in the silicon single crystal is equal to or less than allowable value. This makes it possible to achieve the required nitrogen doping amount at low cost while achieving the low carbon-concentration specification.

Method for producing a silicon single crystal doped with nitrogen and having a controlled amount of carbon impurities

A method of producing a silicon single crystal, including pulling a silicon single crystal by Czochralski method while a magnetic field is applied to a raw material melt, including: setting a diameter on pulling the silicon single crystal to 300 mm or more, setting a growth axis direction of the silicon single crystal to &#x3c;111&#x3e;, and growing the silicon single crystal so as to satisfy a relation of 1096/D&#x2212;(0.134&#xd7;M+80&#xd7;R)/D&#x3e;0.7, wherein D [mm] is the diameter on pulling the silicon single crystal, M [Gauss] is a central magnetic field strength at a surface of the raw material melt, and R [rpm] is a rotation rate of the silicon single crystal. This makes it possible to produce a &#x3c;111&#x3e; crystal with favorable macroscopic RRG distribution and microscopic variation of resistivity.

Method of producing silicon single crystal, and silicon single crystal wafer

A silicon single crystal growing apparatus based on a Czochralski method arranges a graphite crucible inside a graphite heater for heating and a quartz crucible inside the graphite crucible and grows a crystal from a raw material melt filling the quartz crucible, and includes a heater outer heat-insulating member outside the graphite heater, a crucible lower heat-insulating member below the graphite crucible, a crucible upper heat-insulating member above straight bodies of the graphite and quartz crucibles, a crucible outer heat-insulating member outside the straight body of the graphite crucible, a crucible inner heat-insulating member inside the straight bodies of the graphite crucible and the quartz crucible, and a heat shielding member above a liquid surface of the raw material melt, the graphite crucible and the quartz crucible being movable upward and downward in a space enclosed with the crucible upper heat-insulating, crucible outer heat-insulating, and crucible inner heat-insulating members.

Silicon single crystal growing apparatus and method for growing silicon single crystal

The present invention provides a method for manufacturing a silicon single crystal wafer, wherein, under a growth condition that V/G&#x2267;1.05&#xd7;(V/G)crt is achieved where V is a growth rate in growth of the silicon single crystal ingot, G is a temperature gradient near a crystal growth interface, and (V/G)crt is a value of V/G when a dominant point defect changes from a vacancy to interstitial Si, a silicon single crystal ingot having oxygen concentration of 7&#xd7;10atoms/cm(ASTM'79) or less is grown, and a silicon single crystal wafer which includes a region where the vacancy is dominant and in which FPDs are not detected by preferential etching is manufactured from the grown silicon single crystal ingot. As a result, there is provided the method that enables manufacturing a low-oxygen concentration silicon single crystal wafer that can be preferably used for a power device with good productivity at a low cost.

Method for manufacturing a defect-controlled low-oxygen concentration silicon single crystal wafer

A method for measuring a distance between a lower end surface of a heat shielding member including a criterion reflector inside a concavity on the lower end surface and a surface of a raw material melt includes: a silicon single crystal is pulled by the Czochralski method while a magnetic field is applied to the raw material melt in a crucible, measuring the distance between the lower end surface of the heat shielding member and the surface of the raw material melt and observing a position of a mirror image of the criterion reflector with a fixed point observation apparatus; and measuring a movement distance of the mirror image with the apparatus and calculating the distance between the lower end surface of the heat shielding member and the surface of the raw material melt from the movement distance of the image and the measured distance.

Method for measuring and controlling distance between lower end surface of heat shielding member and surface of raw material melt and method for manufacturing silicon single crystal

A single-crystal manufacturing apparatus according to the Czochralski method, including: a crucible that contains a raw material; a main chamber configured to accommodate a heater for heating and melting the raw material; and a pulling chamber configured to pull and accommodate a grown single crystal, the pulling chamber being continuously provided above the main chamber; an inner shield provided between the heater and the main chamber and for insulating heat radiated from the heater, and a supporting member for supporting the inner shield from below. The inner shield is supported at three or more supporting points contacting the supporting member, and a lower end of the inner shield except at the supporting points does not contact the supporting member.

Single-crystal manufacturing apparatus and single-crystal manufacturing method

A silicon single crystal growth method of pulling up and growing a single crystal from a melt of a silicon raw material melted in a quartz crucible based on a Czochralski method, the method comprising the steps of: applying a direct current voltage in such a manner that an outer wall of the quartz crucible acts as a positive electrode and an electrode immersed into the melt of the silicon raw material acts as a negative electrode, the immersed electrode being placed separately from a pulling member for pulling the single crystal; and growing the single crystal with the pulling member while passing an electric current through the electrode, and a pulling apparatus thereof.

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Nishigo-mura, Japan

Kosei Sugawara