Shin-etsu Handotai Co., Ltd.

Shin-etsu Handotai Kabushiki Kaisha

Shin-estu Handotai Co., Ltd.

Atsushi Ozaki

Yoshihiro Hirano

Masahiko Urano

Nobuo Katsuoka

Masahiro Sakurada

Nobuaki Mitamura

Tomohiro Kakegawa

Hideki Nakano

Makoto Iida

Masahiko Baba

Izumi Fusegawa

Tomohiko Ohta

Susumu Sonokawa

Michiaki Oda

Naoki Nagai

Isamu Harada

Tetsuhiro Oda

Munenori Tomita

Akiho Maeda

Chihiro Tashiro

Toshio Hisaichi

The present invention is a method for producing a single crystal with pulling the single crystal from a raw material melt in a chamber by CZ method, wherein when growing the single crystal, where a pulling rate is defined as V and a temperature gradient of the crystal is defined as G during growing the single crystal, the temperature gradient G of the crystal is controlled by changing at least two or more of pulling conditions. Thereby, there is provided a method for producing a single crystal in which when the single crystal is grown by CZ method, V/G can be controlled without lowering a pulling rate V, and thus the single crystal including a desired defect region can be produced effectively for a short time.

Method for producing a single crystal and a single crystal

A method for producing a single crystal in which when the single crystal is grown by Czochralski method, V/G is controlled by controlling a fluctuation of a temperature gradient G of the crystal which is being pulled without lowering a pulling rate V, thereby the single crystal including a desired defect region over a whole plane in a radial direction of the crystal entirely in a direction of the crystal growth axis can be produced effectively for a short time at a high yield.

The present invention is a method for producing a single crystal of which a whole plane in a radial direction is a defect-free region with pulling the single crystal from a raw material melt in a chamber by Czochralski method, wherein a pulling condition is changed in a direction of the crystal growth axis during pulling the single crystal so that a margin of a pulling rate is always a predetermined value or more that the single crystal of which the whole plane in a radial direction is a defect-free region can be pulled. Thereby, there can be provided a method for producing a single crystal in which when a single crystal is produced by CZ method, the single crystal of which a whole plane in a radial direction is a defect-free region entirely in a direction of the crystal growth axis can be produced with stability.

Method for producing single crystal and single crystal

An apparatus and a method capable of automatically adjusting an initial position of the surface of a melt without an operator are provided. In a single crystal puller using a wire as a suspender for a seed crystal for growing a single crystal of silicon or the like according to the CZ method, a reference position of the seed crystal is detected, the wire is unwound to lower the end of the wire to a position higher by a distance W-X from the reference position and then pulled upward above said reference position to correct the wire for an extension due to the weight of a single crystal attached thereto. Also, the wire is left above a melt for about ten minutes to provide a constant amount of extension to the wire due to heat of the melt. These operations are automatically performed.

Method for adjusting initial position of melt surface

An apparatus and a method capable of automatically adjusting an initial position of the surface of a melt without an operator are provided. In a single crystal puller using a wire as a suspender for a seed crystal for growing a single crystal of silicon or the like according to the CZ method, a reference position of the seed crystal is detected, the wire is unwound to lower the end of the wire to a position higher by a distance W-X from the reference position and then pulled upward above said reference position to correct the wire for an extension due to the weight of a single crystal attached thereto. Also, the wire is left above a melt for about ten minutes to provide a constant amount of extension to the wire due to heat of the melt These operations are automatically performed.

Apparatus for adjusting initial position of melt surface

A feeding reservoir 11 for intermittently or continuously feeding granular raw material into a pulling apparatus 1, a chamber 13 connected to the feeding reservoir 11 through a gate valve 12, a granular raw material supply section 15 by which the granular raw material is supplied to the chamber 13 through a gate valve 14 and a pressure adjustment means 20 which adjusts the inner pressure of the chamber 13 is provided, and the granular raw material is fed to the feeding reservoir 11 while maintaining the inner pressure of the feeding reservoir 11 as the same as the inner pressure of the single crystal pulling apparatus 1. This feeding method and structure makes it possible to feed an additional amount of granular raw material even during the continuous charging process and or the recharging process without interrupting the process and also to pull a heavy single crystal rod with a large diameter without increasing the capacity of the feeding reservoir.

Method for feeding a granular raw material and feeding apparatus

A crystal pulling apparatus is disclosed which employs the Czochralski method. The crystal pulling apparatus is operated while a heater for heating a material melt in a crucible is controlled by the main controller of a main system. When maintenance of a heating state is disabled for some reason, a relay of a signal changeover circuit is switched so as to maintain the heating state under control of the backup controller of a backup system, thereby maintaining the material melt in a molten state. Thus, even when it becomes impossible for the main system to heat the material melt within the crucible, the material melt can be prevented from becoming solidified.

Crystal pulling apparatus

A method for measuring a diameter of a single crystal ingot pulled up in a single crystal pulling apparatus comprising: calculating the weight of the pulled-up single crystal, calculating the descent amount of the melt surface relative to the crucible wall from the calculated pulled-up weight of the grown single crystal, and then either correcting the value of the ingot diameter actually measured by the optical sensor in response to the descent amount of the melt surface level or raising the crucible by an amount equal to the descent amount of the surface level.

Method for measuring the diameter of a single crystal ingot

The cutting process is executed after the grinding process and for one semiconductor ingot, one grinding device and one inner diameter saw slicing machine are used to perform grinding process and cutting process respectively. During the grinding process, the entirety of the cylindrical body portion of the semiconductor ingot is cylindrically ground, a portion of the tail end is cylindrically ground, the orientation flat position is determined and an orientation flat is formed by surface grinding. During the cutting process the tail portion is cut off and a sample for lifetime measurement is taken and a wafer sample is cut off from the end of the cylindrical body portion on the tail side. The semiconductor ingot is reversed in the direction of the axis and the head portion of the semiconductor ingot is cut off and a wafer sample is cut off from the cylindrical body portion on the head side. Wafer samples are cut off from the end of the cylindrical body portion on the head side and from the middle portion of cylindrical body portion to divide the cylindrical body portion into two blocks.

Semiconductor ingot machining method

The diameter, the orientation flat width/notch depth and the length of the block 10p are measured by the measuring devices 71a, 71b and 71c respectively and then the machining errors .DELTA.Dp, .DELTA.Wp and .DELTA.Lp in the measured values against the set values are calculated at the error calculation unit 833. Then .DELTA.Dp, .DELTA.Wp and .DELTA.Lp are stored in memory at the memory unit 834 in correspondence with the identification codes IDi and IDj of the grinding device 5i (i=1-N) and the cutting device 6j (j=1-M) that performed the machining. Then at the average value calculation unit 835, the average values of .DELTA.Dp and .DELTA.Wp for each of the grinding devices 51-5N and the average value of the .DELTA.Lp for each of the cutting devices 61-6M are calculated. The average values of .DELTA.Dp and .DELTA.Wp are supplied to the corresponding grinding device 5i as the diameter correction value and the width/depth correction value respectively and the average value of .DELTA.Lp is sent to the corresponding cutting device 6j as the length correction value from the transmission unit 836.

Machining error correction apparatus

The present invention provides control of single crystal growth after the recovery from power failure when controlling crystal growth in an automatic mode. A source voltage is supplied to a controller 70 through a no-break power supply 62. At the time of recovery from power failure, the controller continues the automatic operation mode with the same control output as that stored when power failure is detected (84, 85) if the power failure time t is t .ltoreq.t.sub.1 (for example, 1 second), switches the control mode to the manual control mode with the same control output as that stored when the power failure is detected (86, 87) if t.sub.1 &lt;t.ltoreq.t.sub.2 (for example, 5 seconds), stops the crystal growth operation and switches the control mode to the manual control mode (88, 89) if t.sub.2 &lt;t.ltoreq.t.sub.3 (for example, 600 seconds), and separates the grown crystal from a melt 22 by upwardly moving the crystal and upwardly moves a crucible 16 (90) if t&gt;t.sub.3.

Single crystal rod pull-up growing apparatus

A conical portion growth control method and an apparatus used in the method grow a conical portion 32B of a single crystal rod 32 by pulling the crystal rod from a melt 16 heated by a heater 14 in the Czochralski method, and aim to enhance reproducibility of the shape of the conical portion 32B and shorten the conical portion 32B. The control method has the steps of presetting a target value pattern 66 of the temperature of a concave portion 46 formed on a heat-insulating material 18 and a target value pattern 64 of the diameter change rate of a growing portion of the crystal rod, measuring the diameter of the crystal growing portion, calculating the change rate of the diameter, measuring the temperature of the concave portion, correcting the target temperature based on a difference between the calculated value and the target value of the diameter change rate, and controlling the amount of electricity supplied to the heater so that the measured temperature becomes equal to the corrected target temperature.

Conical portion growth control method and apparatus

A method for controlling an oxygen concentration of a single crystal which is pulled up in a Czochralski-method type single crystal pulling apparatus having a hermetical chamber in which the single crystal is pulled up and an inert gas supply and exhaust system by means of which an inert gas is supplied to the hermetical chamber and exhausted therefrom; the method being characterized in that the pneumatic pressure in the hermetical chamber and the supply rate of the inert gas are controlled in accordance with a prepared control pattern with respect to the proportion of the length of the as-grown crystal to the aimed final length thereof or with respect to the passage of time.

Method of controlling oxygen concentration in single crystal and an

Disclosed is a method of controlling the diameter of a single crystal produced by the Czochralski method. The diameter of a tapered portion of the single crystal is controlled by controlling the temperature of a melt in a crucible and the rotational speed of the crucible. The control range of the rotational speed of the crucible is made narrower as the diameter of the tapered portion approaches closer to that of a body portion, and the rotational speed is made constant while the body portion is grown.

Crystal diameter controlling method

A melt-surface initial position adjusting apparatus which is suitable for use in a monocrystal growing system employing the Czochralski method to adjust the vertical position of the melt surface before the growing of a monocrystal. The apparatus can ensure a highly precise measurement of a crystal-diameter measuring device, thereby enabling a reduction in the costs of producing a monocrystal bar. Before the growing of a crystal, the vertical position (H) of the surface (16A) of a melt within a crucible is measured. The crucible is moved vertically on the basis of the measured value in such a manner as to maintain the distance (L) between the melt surface (16A) and an image sensor (28) for measuring the crystal diameter at a predetermined value.

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Annaka, Japan

Atsushi Ozaki