Komatsu Electronic Metals Co., Ltd.

Komatsu Denshi Kinzoku Kabushiki Kaisha

Sumco Techxiv Corporation

Shigeki Kawashima

Hiroshi Inagaki

Shoei Kurosaka

Makoto Kamogawa

Junsuke Tomioka

Toshirou Kotooka

Tadashi Hata

Masahiro Shibata

Kentaro Nakamura

Shigeo Morimoto

Yoshinobu Hiraishi

Hiroshi Monden

Kozo Nakamura

Susumu Maeda

Toshiaki Saishoji

Tadayuki Hanamoto

Daisuke Ebi

Hirotaka Nakajima

Kengo Hayashi

Yoshiyuki Shimanuki

Masanori Honma

Nobuyuki Fukuda

A method for manufacturing a single crystal semiconductor, in which, in a process of pulling up the single crystal semiconductor from melt for growing it, an impurity is incorporated more uniformly into the single crystal semiconductor so that a variation in impurity concentration across the semiconductor wafer surface can be reduced, and thus, the planarity of the wafer can be improved. In the process of pulling-up the single crystal semiconductor (), fluctuation in a pulling-up speed is controlled, whereby the variation in concentration of the impurity in the single crystal semiconductor () is reduced. Especially, a width of speed fluctuation (&#x394;V) in 10 seconds is adjusted to less than 0.025 mm/min. Furthermore, in carrying out the control for adjusting the pulling-up speed such that a diameter of the single crystal semiconductor () becomes a desired diameter, a magnetic field having strength of 1,500 gauss or more is applied to the melt ().

Method for manufacturing single crystal semiconductor

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 single crystal semiconductor manufacturing method for realizing a dislocation-free single crystal while not varying or hardly varying electric power supplied to a heater when and after a seed crystal comes into contact with a melt. The allowable temperature difference &#x394;Tc not causing dislocation in the seed crystal is determined according to the concentration (C) of the impurities added to the seed crystal () and the size (diameter D) of the seed crystal (). When the seed crystal () comes into contact with the melt (), electric power supplied to a bottom heater () is fixed, and a magnetic field produced by a magnet () is applied to the melt (). Electric power supplied to a main heater () is controlled so that the temperature at the surface of the melt () which the seed crystal () comes into contact with may be a target value. After the seed crystal () comes into contact with the melt (), single crystal silicon is pulled up without performing a necking process.

Single crystal semiconductor manufacturing apparatus and method

The present invention is to produce a silicon crystal wherein the boron concentration in the silicon crystal and the growth condition V/G are controlled so that the boron concentration in the silicon crystal is no less than 1&#xd7;10atoms/cmand the growth condition V/G falls within the epitaxial defect-free region &#x3b1;whose lower limit line LNis the line indicating that the growth rate V gradually drops as the boron concentration increases. A silicon wafer is also produced wherein the boron concentration in the silicon crystal and the growth condition V/G are controlled so as to include at least the epitaxial defect region &#x3b2;, and both the heat treatment condition and the oxygen concentration of the silicon crystal are controlled so that no OSF nuclei grow to OSFs.

Method for producing silicon wafer

A process for producing a single-crystal semiconductor and an apparatus therefor. A single-crystal semiconductor of large diameter and large weight can be lifted with the use of existing equipment not having any substantial change thereto while not influencing the oxygen concentration of single-crystal semiconductor and the temperature of melt and while not unduly raising the temperature of seed crystal. In particular, the relationship (LLL) between the allowable temperature difference (&#x394;T) and the diameter (D) of seed crystal () is preset so that the temperature difference between the seed crystal () at the time the seed crystal () is immersed in the melt and the melt () falls within the allowable temperature difference (&#x394;T) at which dislocations are not introduced into the seed crystal (). In accordance with the relationship (LLL), the allowable temperature difference (&#x394;T) corresponding to the diameter (D) of seed crystal () to be immersed in the melt is determined. Temperature control is conducted so that at the time the seed crystal () is immersed in the melt () the temperature difference between the seed crystal () and the melt () falls within the determined allowable temperature difference (&#x394;T).

Process for producing single-crystal semiconductor and apparatus for producing single-crystal semiconductor

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

An object of the invention is to provide a single crystal clamping device and a single crystal supporting method. The single crystal clamping device does not become inclined and does not vibrate, and the center of the single crystal clamping device is congruous to the center of the growing single crystal. An apparatus for pulling up single crystals of the present invention, comprises: a single crystal pulling up wire for pulling up a seed crystal immersed in a melt of a raw material; a single crystal clamping device for clamping one end of the single crystal grown beneath the seed crystal; a wire-winding mechanism fixed on the single crystal clamping means and winding up the single crystal pulling up wire so as to adjust a speed of the single-crystal pulling up wire corresponding to the ascending/descending speeds of the single crystal clamping device; a pulling up wire-load cell for detecting the load applied on the crystal; and a summation load cell for measuring the combined load applied on the crystal pulling up wire and the single crystal clamping device.

Apparatus for pulling up single crystals and single crystal clamping

A single crystal pulling method includes the steps of: immersing seed crystal in a melt; growing single crystal around the seed crystal and reducing its diameter to remove dislocation in the single crystal; prior to forming a straight waist product portion of single crystal having a prescribed diameter, forming a straight waist holding portion having a diameter smaller than the prescribed diameter; holding the straight waist holding portion by using a single crystal holding device; and pulling the straight waist product portion while the straight waist holding portion is held. Preferably the step of forming the straight waist holding portion includes a step of varying a pulling speed to make unevenness in the surface thereof.

Single crystal pulling method

A crystal-clamping fixture 30 is suspended by a pulling up mechanism 1 through the use of wires. The crystal-clamping fixture 30 includes a box 31 and a plurality of holding rods 32. The box 31 has two openings formed on its top and bottom sides. The reduced portion 2a, the enlarged portion 2b and the necked portion 2c formed beneath the seed crystal 5 are allowed to penetrate through the two openings during the pulling up operation. A plurality of 'S' shaped slots 31a, 31b are formed on the lateral sides of the box 31. The holding rods 32 capable of rotating along the path of the 'S' shaped slots 31a, 31b are horizontally disposed within the box 31 by inserting their two end portions through the 'S' shaped slots 31a, 31b. The holding rods kept restrained at the upper ends of the 'S' shaped slots are pushed out by the conic surface formed at the upper part of the enlarged portion 2b and rotate and descend to reach the lower ends of the 'S' shaped slots. At the time the crystal-clamping fixture 30 is directed to ascend a small distance, then the holding rods 32 contact the conic surface formed between the enlarged portion 2b and the necked portion 2c to clamp the single crystal 2.

Apparatus and method for pulling up single crystals

A method for fabricating a semiconductor single crystal by the MCZ method by which it is possible to pull large diameter and heavy semiconductor single crystals without breaking the contraction portion, is provided. In the contracting step, change the shape of the crystal growth interface by making the range of the temperature fluctuation caused by convection in the vicinity of the melt surface more than 5.degree. C. so as to eliminate the dislocation in the contracted portion. When a transverse magnetic field is applied by magnets 6,6, the magnetic field intensity is set below 2000 Gauss to properly change the shape of the crystal growth interface to form the contracted portion 10. Thus,even though the diameter of the contracted portion 10 is larger than normal, free dislocation is achieved. After the dislocation is eliminated, the magnetic field intensity is recovered and shoulder 11 is formed. When a cusp magnetic field is applied, the contracting is performed when the magnetic field intensity of one of the upper-and-lower magnets being increased while the magnetic field intensity of another magnet is decreased or the upper-and-lower magnets are moved in a vertical direction to make the vicinity of the melt surface similar to a longitudinal magnetic field. After dislocation is eliminated, the magnetic field intensity of the upper-and-lower magnets or the position of the magnets is recovered.

Magnetic field-applied fabrication method for a semiconductor single

This invention provides a melt receiver for a semiconductor single-crystal manufacturing device, which is capable of protecting the main chamber from being damaged by the outflow of the melt or dropping of the debris of the broken crucibles and therefore preventing steam explosion. The melt receiver 1 is consisted of an adiabatic member 3 made of carbon fibers; a cover 2 made of high strength C/C material which shelters the surface of the adiabatic member 3; and a bottom plate 4. A groove 2a is formed on the upper surface of the cover 2. The groove 2a has a size capable of accommodating all of the melt stored in the quartz crucible 7. The melt flown out or articles dropped down due to damage of the crucible are received by the melt receiver 1, and the melt flown out can not reach the bottom of the main chamber 9. The melt receiver can also be consisted of a melt absorption layer made of adiabatic material, and a melt isolation layer made of graphite or high strength C/C material.

Growing community of inventors

Kanagawa, Japan

Shigeki Kawashima