Abstract: 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° C., be G (° C./mm), V/G ranges from 0.16 to 0.18 mm2/° 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° 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 13×1017 atoms/cm3, an initial heat treatment temperature is at least up to 500° C. and a temperature is raised at up to 1° C./min at least within 700 to 900° C.

Abstract: A polishing apparatus comprises a polishing plate (24), an abrasive cloth (25) attached to the surface of the polishing plate (24), a chuck (19) for holding and pressing one surface of a wafer (39) against the abrasive cloth (25), and a circular retaining ring (23) concentrically arranged on the periphery of the chuck (19). The retaining ring (23) is rotatable and vertically movable with respect to the chuck (19), and is pressed against the abrasive cloth (25) during the lapping step. The retaining ring (23) is lifted upward during the final polishing step, thereby preventing lapping grains from being brought into the final polishing stage. Accordingly, lapping and final polishing can be successively conducted using the same polishing head. With this structure, cost cutting of the apparatus can be realized, since lapping and final polishing are successively conducted using the same polishing head without bringing the lapping grains used for lapping into the final polishing stage.

Abstract: A melt level or the gap between a melt surface and a heat shield is measured accurately irrespective of how the melt surface is. A laser beam from a range-finding unit is reflected by a scanning mirror and projected on a melt surface through an entrance window and a quartz prism in a chamber of a puller. After specular reflection, the beam forms a measurement spot in the bottom of a heat shield and scatters. Part of the scatter, after specular reflection at the melt surface (secondary reflection), passes through the prism, the entrance window and the scanning mirror to the range-finding unit. The range-finding unit carries out triangulation using the distance between a laser source and a photodetector therein, and the angle of incidence and the angle of the received laser beam.

Abstract: 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.

Abstract: 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.

Abstract: 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 (L1, L2, L3) between the allowable temperature difference (?T) and the diameter (D) of seed crystal (14) is preset so that the temperature difference between the seed crystal (14) at the time the seed crystal (14) is immersed in the melt and the melt (5) falls within the allowable temperature difference (?T) at which dislocations are not introduced into the seed crystal (14). In accordance with the relationship (L1, L2, L3), the allowable temperature difference (?T) corresponding to the diameter (D) of seed crystal (14) to be immersed in the melt is determined.

Abstract: 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 (11) is pulled up form a silicon melt (13), the shape of a solid-liquid interface (14) which a boundary between the silicon melt (13) and the silicon single crystal (11) and the temperature distribution on the side face (11b) of a single crystal under being pulled up are appropriately controlled.

Abstract: A susceptor structure capable of discharging the atmosphere containing dopant species and filling a wafer pocket, without causing a large quantity of a raw material gas to flow from the front surface side of a susceptor to under the susceptor. The susceptor having an approximately round disk shape and having a concave wafer pocket on the front surface thereof for accommodating a wafer, comprises a gas inlet notch passing through from a side surface or a rear surface of the susceptor to the wafer pocket, and a gas discharge notch passing through from the wafer pocket to the side surface or the rear surface of the susceptor. A carrier gas is introduced from the gas inlet notch of the susceptor into the wafer pocket, as shown by arrow b and the gas present inside the wafer pocket is discharged from the gas discharge notch, as shown by arrow c, by using the rotation of the susceptor during epitaxial film growth.

Abstract: 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.

Abstract: An epitaxial silicon wafer which comprises a silicon wafer produced by a method characterized as comprising pulling up a silicon single crystal under a condition wherein when an oxygen concentration is 7×1017 atoms/cm3 a nitrogen concentration is about 3×1015 atoms/cm3 or less, and when an oxygen concentration is 1.6×1018 atoms/cm3 a nitrogen concentration is about 3×1014 atoms/cm3 or less, and, an epitaxial film formed on the wafer. The epitaxial film, being formed on such a wafer, has crystal defects, which are observed as LPD of 120 nm or more on the epitaxial film, in a range of 20 pieces/200-mm wafer or less. The epitaxial silicon wafer contains nitrogen atoms doped therein and also has satisfactory characteristics as that for use in a semiconductor device.

Abstract: 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.

Abstract: A melt level detector is provided for detecting the melt level of a CZ furnace by triangulation. The laser beam (2) from a laser source (1) is moved in radial directions of a crucible (14) in the CZ furnace to find a location where a photodetector system (5, 7) can receive the reflection (4) from the melt level (3), and the laser beam (2) is fixed at the location. Since the measurements thus take place within an extremely small angular range of the laser beam, the melt level (3) can be detected with little effect of noise on the melt level (3) while eliminating complexity of the device.

Abstract: A device for producing single-crystal ingot, provided with coolers (19) using a piping system through which cooling water failure caused by water leakage and at the same time to find out conditions for maximizing a production efficiency, the coolers (19) are disposed at portions of the inner sides of thermal shielding elements (18) and the lower ends (19a) of cooling pipes are so set as to be positioned up to 150 mm high from the surface (12a) of molten silicon liquid.

Abstract: There is described a method which enables stable manufacture of a high-quality, ultra-thin epitaxial silicon wafer, as well as an epitaxial silicon wafer capable of bearing shipment manufactured by the method. A method of manufacturing an epitaxial silicon wafer having an ultra-thin epitaxial film, by means of forming an epitaxial film on a silicon wafer after having annealed the silicon wafer, includes the steps of: sufficiently smoothing COPs formed in the surface of the silicon wafer by means of appropriately setting annealing conditions according to an size of COPs in the vicinity of a surface of the silicon wafer; and forming an epitaxial film through epitaxial growth.