Komatsu Electronic Metals Co., Ltd.

Komatsu Denshi Kinzoku Kabushiki Kaisha

Sumco Techxiv Corporation

Toshiaki Saishoji

Kozo Nakamura

Toshirou Kotooka

Junsuke Tomioka

Kentaro Nakamura

Hiroshi Inagaki

Shigeo Morimoto

Yoshinobu Hiraishi

Hiroshi Monden

Shigeki Kawashima

Makoto Kamogawa

Toshimichi Kubota

Tadayuki Hanamoto

Daisuke Ebi

Kengo Hayashi

Tadashi Hata

Takashi Yokoyama

Susumu Maeda

Yoshiyuki Shimanuki

Shinya Sadohara

Tetsuhiro Iida

Toshiro Kotooka

Fumitaka Ishikawa

Hirotaka Nakajima

Shinji Togawa

Shin Matsukuma

Masashi Nishimura

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 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 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

In growing silicon single crystals by the CZ method, the cooling rate in the 1150-1080&deg; C. temperature zone (defect-forming temperature range) where the grown-in defects are formed is set at more than 2.0&deg; C./min to manufacture single crystals having an as-grown LSTD density of larger than 3.0&times;10,/cm,or a FPD density of larger than 6.0&times;10,/cm,. As this single crystal has a small defect size, thus the dissolution rate of the defects increases by the heat treatment in a non-oxidizing atmosphere containing a hydrogen gas, so the effect of the hydrogen heat treatment can extend to the depth more than 3 &mgr;m from the wafer surface.

Silicon wafer for hydrogen heat treatment and method for manufacturing the same

This invention provides a method for manufacturing silicon single crystals. The method is capable of eliminating void defects existing in deep regions of a silicon single crystal despite the size of the silicon single crystal. The silicon single crystals according to this invention are pulled the radius of a ring-shaped oxidation induced stacking fault (OSF ring) of a wafer is larger than half the radius of the wafer during the process of thermal oxidation treatment.

Method for manufacturing silicon single crystals and wafers adapted for producing semiconductors

In growing silicon single crystals by the CZ method, the cooling rate in the 1150-1080.degree. C. temperature zone (defect-forming temperature range) where the grown-in defects are formed is set at more than 2.0.degree. C./min to manufacture single crystals having an as-grown LSTD density of larger than 3.0.times.10.sup.6 /cm.sup.3 or a FPD density of larger than 6.0.times.10.sup.5 /cm.sup.3. As this single crystal has a small defect size, thus the dissolution rate of the defects increases by the heat treatment in a non-oxidizing atmosphere containing a hydrogen gas, so the effect of the hydrogen heat treatment can extend to the depth more than 3 .mu.m from the wafer surface.

Silicon wafer for hydrogen heat treatment and method for manufacturing

A single crystal is pulled to a length at which the beginning of the body of the single crystal is assumed sufficiently to have been cooled down to a temperature below 1000.degree. C.; then the single crystal being pulled is detached from the molten silicon by pulling it at a speed high enough to cut it out from the molten silicon. Then oxygen precipitation heat-treatment is performed on the single crystal to locate the portion of AOP. AOP arises at the boundary of grown-in defects being formed zone while the single crystal passes through 1100.degree. C., and the position is at about 1100.degree. C. immediately before, detaching the single crystal out from the molten silicon. Therefore, the position at temperature 1100.degree. C. in the single crystal immediately before detaching the single crystal out from the molten silicon are known, then the temperature distributions of the single crystal immediately before detaching it out from the molten silicon can be decided easily. If the speed at which the temperature range near 1100.degree. C. is passed through is controlled, then the occurrence of the defects while growing the single crystal can be controlled.

Simple method for detecting temperature distributions in single crystals

When the silicon single crystal is pulled up, the nucleation rate of the void cluster is obtained from the forming energy of the cluster of the vacancies in the silicon single crystal. The growth shrinkage of the cluster is obtained basing on the deviation of the flowing-into amount to the cluster of the vacancies and the self-interstitials, and the pulling-up speed or the temperature distribution of the furnace is modified to inhibit the growth of the cluster so as to inhibit the grown-in defects of the silicon single crystal.

Method of controlling defects of a silicon single crystal

In the manufacture of a single crystal using a semiconductor single-crystal pulling apparatus equipped with a radiation screen, the time of passage of the single crystal through the high-temperature region of 1050.degree. C. and above is made to be long and the time of passage of the single crystal through the temperature region of about 900.degree. C.-500.degree. C. is made to be short. The semiconductor single-crystal pulling apparatus is so constructed that a radiation screen comprises an upper screen of 3-layer construction consisting of a heat-insulating member made of graphite or ceramics fiber clad with outer members made of graphite and a lower screen 3 of single-layer construction made of graphite, quartz or fine ceramics. Radiant heat from the molten liquid heats the lower part of single crystal as it passes through lower screen, thereby prolonging its period of passage through the high-temperature region. The radiant heat cannot reach single crystal when it is surrounded by upper screen, so it is cooled comparatively abruptly and can pass through the temperature region of about 900-500.degree. C. in a short time.

Semiconductor single-crystal pulling apparatus

Growing community of inventors

Kanagawa, Japan

Toshiaki Saishoji