Abstract: Leakage of silicon melt is monitored and touch of a seed crystal at the silicon melt is detected, and in addition, reinforcement of a vitreous silica crucible to be endurable during pulling for a long time and decrease of impurity concentration of a silicon single crystal can be expected. A method for manufacturing a silicon single crystal is provided.

Abstract: By providing a method capable of avoiding invasion of starting material powder for crucible into an inner face of the crucible, it is made possible to reliably avoid the invasion of foreign substances into a vitreous silica crucible until an actual use time of the crucible and to handle the crucible with no contamination. A cover 3 mounted onto an opening portion 2 of a vitreous silica crucible 1, comprising a flange portion 4 in close contact with an outer peripheral end 2a of the opening portion 2, is mounted onto the crucible 1.

Abstract: Leakage of silicon melt is monitored and touch of a seed crystal at the silicon melt is detected, and in addition, reinforcement of a vitreous silica crucible to be endurable during pulling for a long time and decrease of impurity concentration of a silicon single crystal can be expected. A method for manufacturing a silicon single crystal is provided.

Abstract: In a method for growing a silicon single crystal, a silicon single crystal is grown by the Czochralski method to have an oxygen concentration of 12×1017 to 18×1017 atoms/cm3 on ASTM-F121 1979. A mixed gas of an inert gas and a gaseous substance containing hydrogen atoms is used as an atmospheric gas for growing the single crystal. A temperature of the silicon single crystal is controlled during the growth of the crystal such that the ratio Gc/Ge of an axial thermal gradient Gc at the central portion of the crystal between its melting point and its temperature of 1350° C. to an axial thermal gradient Ge at the periphery of the crystal between its melting point and its temperature of 1350° C. is 1.1 to 1.4. The axial thermal gradient Gc at the central portion of the crystal is 3.0 to 3.5° C./mm.

Abstract: Provided is a seed crystal for pulling a silicon single crystal that can reduce generation of slip dislocation due to thermal shock that occurs at the time of contact with a silicon melt, suppress propagation of this slip dislocation, and eliminate dislocation even though a diameter of a neck portion is larger than that in conventional examples. The seed crystal for pulling a silicon single crystal according to the present invention is an improvement in a seed crystal used for pulling a silicon single crystal based on a CZ method, and its characteristics configuration lies in that the seed crystal is cut out from a silicon single crystal pulled from a carbon-doped silicon melt and a concentration of carbon with which the seed crystal is doped is in the range of 5×1015 to 5×1017 atoms/cm3.

Abstract: The present invention provides a silicon single crystal comprising a seed crystal, a narrowed portion whose diameter decreases, and at its lower end, a neck portion, wherein in a front projection view, the contour of the narrowed portion is located inside the straight line connecting the contour of the lower end of the seed crystal to the contour of the upper end of the neck portion, and the contour of the neck portion is made to be a tangent at the lower end of the narrowed portion. At this time, the length L of the narrowed portion in a pulling direction and the difference d between the radius of the seed crystal and the radius of the narrowed portion relative to the diameter W of the seed crystal is appropriately adjusted and further the contour of the narrowed portion is desirably formed with any one of parabolas, circular arcs and elliptic arcs.

Abstract: A method for growing silicon single crystal by the CZ method, namely by feeding silicon materials for crystal into a crucible to melt the materials, and growing a silicon single crystal on the lower end of the seed crystal, comprises: forming a narrowingly tapered portion with a gradually decreased seed crystal diameter by pulling up the seed crystal inserted in the melt; and providing increased or decreased neck diameter regions in the process of forming a neck in such a manner that each increased neck diameter is provided by increasing the neck diameter, followed by reverting the neck diameter to the original diameter, or alternatively, each decreased neck diameter region is provided by decreasing the neck diameter, followed by reverting the diameter to the original diameter, thereby enabling to reliably eliminate dislocations remaining in the central axial region of the neck in the step of necking.

Abstract: A silicon single crystal is grown using the Czochralski method. During the crystal growth, a thermal stress is applied to at least a portion of the silicon single crystal. A gaseous substance containing hydrogen atoms is used as an atmospheric gas for growing the crystal.

Abstract: This method for producing silicon single crystals includes: growing a silicon single crystal by the Czochralski method while cooling at least part of the silicon single crystal under growth with a cooling member which circumferentially surrounds the silicon single crystal and has an inner contour that is coaxial with a pull axis, wherein an ambient gas in which the silicon single crystal is grown includes a hydrogen-atom-containing substance in gaseous form. This silicon single crystal is produced by the above method.

Abstract: A high-resistance silicon wafer is manufactured in which a gettering ability, mechanical strength, and economical efficiency are excellent and an oxygen thermal donor is effectively prevented from being generated in a heat treatment for forming a circuit, which is implemented on the side of a device maker. A heat treatment for forming an oxygen precipitate nucleus is performed at 500 to 900° C. for 5 hours or more in a non-oxidizing atmosphere and a heat treatment for growing an oxygen precipitate is performed at 950 to 1050° C. for 10 hours or more on a high-oxygen and carbon-doped high-resistance silicon wafer in which resistivity is 100 ?cm or more, an oxygen concentration is 14×1017 atoms/cm3 (ASTM F-121, 1979) or more and a carbon concentration is 0.5×1016 atoms/cm3 or more. By these heat treatments, a remaining oxygen concentration in the wafer is controlled to be 12×1017 atoms/cm3 (ASTM F-121, 1979) or less.

Abstract: A high-resistance silicon wafer is manufactured, in which a gettering ability and economical efficiency is excellent and an oxygen thermal donor is effectively prevented from being generated in a heat treatment for forming a circuit, which is to be implemented on the side of a device manufacturer. In order to implement the above, a high-temperature heat treatment at 1100° C. or higher is performed on a carbon doped high-resistance and high-oxygen silicon wafer in which specific resistivity is 100 ?cm or more and a carbon concentration is 5×1015 to 5×1017 atoms/cm3 so that a remaining oxygen concentration becomes 6.5×1017 atoms/cm3 or more (Old-ASTM). As this high-temperature treatment, an OD treatment for forming a DZ layer on a wafer surface, a high-temperature annealing treatment for eliminating a COP on the surface layer, a high-temperature heat treatment for forming a BOX layer in a SIMOX wafer manufacturing process and the like can be used.

Abstract: A silicon annealed wafer having a sufficient thick layer free from COP defects on the surface, and a sufficient uniform BMD density in the inside can be produced by annealing either a base material wafer having nitrogen at a concentration of less than 1×1014 atoms/cm3, COP defects having a size of 0.1 ?m or less in the highest frequency of occurrence and no COP defects having a size of 0.2 ?m or more, oxygen precipitates at a density of 1×104 counts/cm2 or more, and BMDs (oxygen precipitates), where the ratio of the maximum to the minimum of the BMD density in the radial direction of the wafer is 3 or less, or a base material wafer grown at specific average temperature gradients within specific temperature ranges and specific cooling times for a single crystal at a nitrogen concentration of less than 1×1014 atoms/cm3, employing the Czochralski method.

Abstract: A high resistivity p type silicon wafer with a resistivity of 100 ?cm or more, in the vicinity of the surface being formed denuded zone, wherein when a heat treatment in the device fabrication process is performed, a p/n type conversion layer due to thermal donor generation is located at a depth to be brought into contact with neither any device active region nor depletion layer region formed in contact therewith or at a depth more than 8 ?m from the surface, and a method for fabricating the same. The high resistivity silicon wafer can cause the influence of thermal donors to disappear without reducing the soluble oxygen concentration in the wafer, whereby even if various heat treatments are performed in the device fabrication process, devices such as CMOS that offer superior characteristics can be fabricated. The wafer has wide application as a substrate for a high-frequency integrated circuit device.

Abstract: To suppress a fluctuation in resistivity around a target value to thereby stably manufacture high resistivity silicon single crystals having almost the same resistivity values in a manufacturing method wherein a silicon raw material is molten to manufacture a high resistivity silicon single crystal in the range of from 100 to 2000 ? cm with a CZ method. In a case where poly-silicon produced with a Siemens method using trichlorosilane as raw material is used as the silicon raw material, an impurity concentration in the silicon raw material is selected so as to be controlled in the range of from ?5 to 50 ppta method in terms of (a donor concentration—an acceptor concentration) and the selected poly-silicon is used. In a case of a MCZ method, the poly-silicon is selected in the range of from ?25 to 20 ppta and the selected poly-silicon is used. Instead of the raw material, poly-silicon produced with a Siemens method using monosilane as raw material is used.

Abstract: In a device and a method for measuring the position of the liquid surface of a melt while a single crystal is being pulled, two measuring-lines are defined in an image of a fusion ring which is captured by means of a two-dimensional CCD camera, the intersections of the respective measuring lines and the fusion ring, on the opposite sides of the fusion ring, are detected, and the central position of the single crystal is calculated based on the intervals between the intersections on the opposite sides of the fusion ring, whereby the position of the liquid surface of the melt is determined.

Abstract: A silicon single crystal is grown using the Czochralski method. During the crystal growth, a thermal stress is applied to at least a portion of the silicon single crystal. A gaseous substance containing hydrogen atoms is used as an atmospheric gas for growing the crystal.

Abstract: In a method for growing a silicon single crystal, a silicon single crystal is grown by the Czochralski method to have an oxygen concentration of 12×1017 to 18×1017 atoms/cm3 on ASTM-F121 1979. A mixed gas of an inert gas and a gaseous substance containing hydrogen atoms is used as an atmospheric gas for growing the single crystal. A temperature of the silicon single crystal is controlled during the growth of the crystal such that the ratio Gc/Ge of an axial thermal gradient Gc at the central portion of the crystal between its melting point and its temperature of 1350° C. to an axial thermal gradient Ge at the periphery of the crystal between its melting point and its temperature of 1350° C. is 1.1 to 1.4. The axial thermal gradient Gc at the central portion of the crystal is 3.0 to 3.5° C./mm.

Abstract: This method for producing silicon single crystals includes: growing a silicon single crystal by the Czochralski method while cooling at least part of the silicon single crystal under growth with a cooling member which circumferentially surrounds the silicon single crystal and has an inner contour that is coaxial with a pull axis, wherein an ambient gas in which the silicon single crystal is grown includes a hydrogen-atom-containing substance in gaseous form. This silicon single crystal is produced by the above method.

Abstract: A high-resistance silicon wafer is manufactured in which a gettering ability, mechanical strength, and economical efficiency are excellent and an oxygen thermal donor is effectively prevented from being generated in a heat treatment for forming a circuit, which is implemented on the side of a device maker. A heat treatment for forming an oxygen precipitate nucleus is performed at 500 to 900° C. for 5 hours or more in a non-oxidizing atmosphere and a heat treatment for growing an oxygen precipitate is performed at 950 to 1050° C. for 10 hours or more on a high-oxygen and carbon-doped high-resistance silicon wafer in which resistivity is 100 ?cm or more, an oxygen concentration is 14×1017 atoms/cm3 (ASTM F-121, 1979) or more and a carbon concentration is 0.5×1016 atoms/cm3 or more. By these heat treatments, a remaining oxygen concentration in the wafer is controlled to be 12×1017 atoms/cm3 (ASTM F-121, 1979) or less.

Abstract: A high-resistance silicon wafer is manufactured, in which a gettering ability and economical efficiency is excellent and an oxygen thermal donor is effectively prevented from being generated in a heat treatment for forming a circuit, which is to be implemented on the side of a device manufacturer. In order to implement the above, a high-temperature heat treatment at 1100° C. or higher is performed on a carbon doped high-resistance and high-oxygen silicon wafer in which specific resistivity is 100 ?cm or more and a carbon concentration is 5×1015 to 5×1017 atoms/cm3 so that a remaining oxygen concentration becomes 6.5×1017 atoms/cm3 or more (Old-ASTM). As this high-temperature treatment, an OD treatment for forming a DZ layer on a wafer surface, a high-temperature annealing treatment for eliminating a COP on the surface layer, a high-temperature heat treatment for forming a BOX layer in a SIMOX wafer manufacturing process and the like can be used.