Shin-etsu Handotai Co., Ltd.

Shin-etsu Handotai, Ltd.

Makoto Iida

Masanori Kimura

Shozo Muraoka

Eiichi Iino

Masaro Tamatsuka

Masahiro Sakurada

Hideki Yamanaka

Norihiro Kobayashi

Hiroshi Takeno

Atsushi Ozaki

Nobuaki Mitamura

Yoshinori Hayamizu

Akihiro Kimura

Satoshi Suzuki

Izumi Fusegawa

Hirotoshi Yamagishi

Kiyotaka Takano

Masahiko Urano

Takatoshi Nagoya

Ken Aihara

Satoshi Soeta

Takahiro Yanagimachi

Katsuhiko Miki

Wei Feig Qu

Hideki Shigeno

Wataru Kusaki

Kazuo Matsuzawa

The present invention is a single-crystal manufacturing method based on the Czochralski method, comprising at least the steps of: producing a melt by heating and melting a crystalline raw material in a crucible with a heater; maturing the melt by keeping the melt at a high temperature; growing a single crystal after dipping a seed crystal into the matured melt, wherein the heater and the crucible are relatively moved up and down in the step of maturing. As a result, there is provided a single-crystal manufacturing method that enables the generation of dislocation to be effectively suppressed and a high quality single crystal to be manufactured at good yield, particularly in case of pulling the single crystal having a large diameter, in manufacture of the single crystal.

Single-crystal manufacturing method

A method for producing semiconductor wafers, from a semiconductor ingot, wherein an oxygen concentration distribution in the growth axis direction is measured in the ingot state (F), a position at which the oxygen concentration is maximum or minimum in a range of a predetermined length is determined as a cut position according to the measurement results (F), the ingot is cut in a perpendicular direction to the growth axis at the cut position into blocks each having the oxygen concentrations being maximum and minimum at both ends thereof (F), each of the blocks is sliced, and thereby semiconductor wafers are produced. Thereby, there can be provided a technique by which when semiconductor wafers are produced from a semiconductor ingot, wafers having oxygen concentration being in a predetermined standard range can be certainly produced.

Method for producing semiconductor wafers and a system for determining a cut position in a semiconductor ingot

A method for producing a single crystal by Czochralski method with pulling a seed crystal from a raw material melt, wherein in which a range of a pulling rate of pulling a single crystal, a temperature gradient at a solid-liquid interface and a highest temperature at an interface between a crucible and a raw material melt are defined. The single crystal is pulled with controlling the pulling rate and/or the temperature gradient at a solid-liquid interface within the determined range. The method produces a single crystal in which a desired defect region and/or a desired defect-free region can be determined more precisely and a single crystal with desired quality can be more surely pulled.

Method for producing a single crystal

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

The present invention provides a method for producing a nitrogen-doped annealed wafer, wherein before a wafer sliced from a silicon single crystal doped with at least nitrogen and polished is subjected to a high temperature heat treatment at 1100&#xb0; C. to 1350&#xb0; C. in an atmosphere of argon, hydrogen or a mixed gas thereof, a step of maintaining the wafer at a temperature lower than the treatment temperature of the high temperature heat treatment is conducted to allow growth of oxygen precipitation nuclei having such a size that the nuclei should be annihilated by the high temperature heat treatment to such a size that the nuclei should not be annihilated by the high temperature heat treatment, and then the high temperature heat treatment is performed. Thus, there are provided a nitrogen-doped annealed wafer with reducing variation of the BMD density after the annealing among silicon single crystal wafers sliced from various positions of the silicon single crystal without being affected by concentration of nitrogen doped in a silicon single crystal and a method for producing the same.

Method for preparing nitrogen-doped annealed wafer and nitrogen-doped and annealed wafer

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 discloses a graphite heater for producing a single crystal used when producing a single crystal by the Czochralski method which comprises at least a terminal part to which electric current is supplied and a cylindrical heat generating part by resistance heating and are provided so as to surround a crucible for containing a raw material melt wherein the heat generating part has heat generating slit parts formed by being provided with upper slits extending downward from the upper end and lower slits extending upwards from the lower end by turns, and a length of at least one slit of the upper slits differs from others and/or a length of at least one slit of the lower slits differs from others so that a heat generating distribution of the heat generating part may be changed. Thereby, there can be provided a graphite heater for producing a single crystal which makes it possible to produce a silicon single crystal with high productivity when the silicon single crystal is pulled in a predetermined defect-free region or a predetermined defect region.

Graphite heater for producing single crystal, apparatus for producing single crystal, and method for producing single crystal

The present invention provides a silicon single crystal wafer having a diameter of 300 mm or more and having a defect-free layer containing no COP for a depth of 3 &#x3bc;m or more from a surface and a method for producing a silicon single crystal, wherein, when a silicon single crystal having a diameter of 300 mm or more is pulled with nitrogen doping by the CZ method, the crystal is grown with a value of V/G [mm/K&#xb7;min] of 0.17 or less, where V [mm/min] is a pulling rate, and G [K/mm] is an average of temperature gradient in the crystal along a pulling axis from the melting point of silicon to 1400&#xb0; C. Thus, there are established conditions for pulling a silicon single crystal and conditions for heat treatment of wafer for obtaining a silicon single crystal wafer having a defect-free layer free from COP for a sufficient depth of the surface layer by pulling a silicon single crystal having a diameter of 300 mm or more, processing the crystal into wafers and subjecting the wafers to the heat treatment.

Silicon single crystal wafer having void denuded zone on the surface and diameter of above 300 mm and its production method

A silicon single crystal wafer grown by the CZ method, which is doped with nitrogen and has an N-region for the entire plane and an interstitial oxygen concentration of 8 ppma or less, or which is doped with nitrogen and has an interstitial oxygen concentration of 8 ppma or less, and in which at least void type defects and dislocation clusters are eliminated from the entire plane, and a method for producing the same. Thus, there are provided a defect-free silicon single crystal wafer having an N-region for the entire plane, in which void type defects and dislocation clusters are eliminated, produced by the CZ method under readily controllable stable production conditions with a wide controllable range, and a method producing the same.

Silicon single crystal wafer and production method thereof and soi wafer

The present invention provides an annealed wafer manufacturing method using a heat treatment method causing no change in resistivity of a wafer surface even when a silicon wafer having boron deposited on a surface thereof from an environment is subjected to heat treatment in an insert gas atmosphere and enabling the heat treatment in an ordinary diffusion furnace not requiring a sealed structure for increasing airtightness nor any specific facility such as explosion-proof facility. The present invention also provides an annealed wafer in which a boron concentration in the vicinity of a surface thereof is constant and crystal defects are annihilated. In the annealed wafer manufacturing method, a silicon wafer having a natural oxide film formed on a surface thereof with boron deposited thereon from an environment is subjected to heat treatment in an atmosphere containing hydrogen gas to remove the deposited boron before the natural oxide film is removed, and then is subjected to heat treatment in an inert gas atmosphere.

Annealed wafer manufacturing method and annealed wafer

According to the present invention, there are provided a silicon wafer, wherein an epi-layer is not formed on a surface, and number of LSTDs having a size of 50 nm or more existing in a surface layer portion is 0.24 number/cm or less; a method for determining production conditions of a silicon single crystal, which comprises pulling nitrogen-doped silicon single crystals by the CZ method while varying V/G and/or PT, producing silicon wafers from the silicon single crystals, subjecting the silicon wafers to a heat treatment, determining acceptability of the wafers based on a predetermined characteristic value, obtaining correlation between the acceptability and V/G and PT, and determining production conditions based on the correlation; and a method for producing a silicon wafer comprising pulling a silicon single crystal so that V/G and PT should be lower than V/G and shorter than PT that are uniquely defined by predetermined nitrogen concentration and oxygen concentration in the silicon single crystal, conditions of heat treatment to which the silicon wafer is subjected, and grown-in defect density of the silicon wafer. According to the present invention, a nitrogen-doped annealed wafer showing a low defect density even under severe examination conditions and little fluctuation thereof depending on the production condition is produced.

Silicon wafer, method for determining production conditions of silicon single crystal and method for producing silicon wafer

A silicon single crystal wafer for epitaxial growth grown by the CZ method, which is doped with nitrogen and has a V-rich region over its entire plane, or doped with nitrogen, has an OSF region in its plane, and shows an LEP density of 20/cm or less or an OSF density of 1&times;10 /cm or less in the OSF region, epitaxial wafer utilizing the substrate, as well as methods for producing them and method for evaluating a substrate suitable for an epitaxial wafer. There are provided a substrate for an epitaxial wafer that suppresses crystal defects to be generated in an epitaxial layer when epitaxial growth is performed on a CZ silicon single crystal wafer doped with nitrogen and also has superior IG ability, epitaxial wafer utilizing the substrate, as well as methods for producing them and method for evaluating a substrate suitable for an epitaxial wafer.

Silicon single crystal wafer for epitaxial wafer, epitaxial wafer, and methods for producing the same and evaluating the same

A method for producing a silicon single crystal in accordance with CZ method, characterized in that before producing the crystal having a predetermined kind and concentration of impurity, another silicon single crystal having the same kind and concentration of impurity as the crystal to be produced is grown to thereby determine an agglomeration temperature zone of grown-in defects thereof, and then based on the temperature, growth condition of the crystal to be produced or temperature distribution within a furnace of a pulling apparatus is set such that a cooling rate of the crystal for passing through the agglomeration temperature zone is a desired rate to thereby produce the silicon single crystal. A silicon single crystal produced in accordance with the above method, characterized in that a density of LSTD before subjecting to heat treatment is 500 number/cm or more and the average defect size is 70 nm or less. The present invention provides by CZ method a silicon single crystal and a silicon wafer wherein the dispersion in size and density of grown-in defects is suppressed effectively and the quality is stabilized regardless of the variety of crystals, and a producing method therefor.

Method for manufacturing silicon single crystal, silicon single crystal manufactured by the method, and silicon wafer

A silicon wafer obtained by slicing a silicon single crystal ingot grown by the Czochralski method with or without nitrogen doping, wherein the silicon wafer has an NV-region, an NV-region containing an OSF ring region or an OSF ring region for its entire plane and has an interstitial oxygen concentration of 14 ppma or less, and a method for producing it, as well as a method for evaluating defect regions of a silicon wafer. Thus, there are provided a silicon wafer that stably provides oxygen precipitation regardless of position in crystal or device production process, and a method for producing it. Further, defect regions of a silicon wafer of which pulling conditions are unknown and thus of which defect regions are also unknown can be evaluated.

Silicon wafer and production method thereof and evaluation method for silicon wafer

In method for manufacturing a silicon single crystal in accordance with a Czochralski method, during the growth of the silicon single crystal, pulling is performed such that a solid-liquid interface in the crystal, excluding a peripheral 5 mm-width portion, exists within a range of an average vertical position of the solid-liquid interface &plusmn;5 mm. There is also disclosed a method for manufacturing a silicon single crystal in accordance with the Czochralski method, wherein during the growth of a silicon single crystal, a furnace temperature is controlled such that a temperature gradient difference &Dgr;G (&equals;Ge&minus;Gc) is not greater than 5&deg; C./cm, where Ge is a temperature gradient (&deg; C./cm) at a peripheral portion of the crystal, and Gc is a temperature gradient (&deg; C./cm) at a central portion of the crystal, both in an in-crystal descending temperature zone between 1420&deg; C. and 1350&deg; C. or between a melting point of silicon and 1400&deg; C. in the vicinity of the solid-liquid interface of the crystal. The method maintains high productivity and enables a silicon single crystal and silicon wafers to be manufactured such that a defect density is very low over the entire crystal cross section, and the oxygen concentration distribution over the surface of each silicon wafer is improved.

Method and apparatus for manufacturing a silicon single crystal having few crystal defects, and a silicon single crystal and silicon wafers manufactured by the same

Growing community of inventors

Gunma, Japan

Makoto Iida