Abstract: The present invention relates to single crystal silicon, in ingot or wafer form, which contains an axially symmetric region in which vacancies are the predominant intrinsic point defect and which is substantially free of agglomerated vacancy intrinsic point defects, wherein the first axially symmetric region comprises the central axis or has a width of at least about 15 mm, and a process for the preparation thereof.

Abstract: A working recipe for NTD CZ and MCZ silicon wafer production is provided. It teaches that a neutron-enhanced S-curve can be constructed by noting that a silicon interstitial (Si.sub.I), emitted due to volume change during the traditional oxygen precipitation, can join a neutron-created vacancy in facilitating further oxygen loss via precipitation. The former relation is: 2Si+2O.sub.I .fwdarw.SiO.sub.2 +Si.sub.i the latter is: vacancy+Si .sub.I +2O.sub.I .fwdarw.SiO ..sub.2 The total loss of oxygen interstitials is:?O.sub.I !=Max(?O .sub.I !.sub.0 ?O .sub.I !.sub.s +min{2(?Si .sub.I !.sub.s +?Si .sub.I !.sub.0). ?vacancy!}),with subscripts 0 and s standing for initial state and S-curve prediction, respectively; ?Si.sub.I !.sub.s equal to 0.5?O .sub.I !.sub.s, and ?vacancy! readily obtainable by computer simulation. ?vacancy! is a function of the cadmium ratio (CR), silicon sample thickness, and total neutron fluence. The final oxygen interstitial content is: ?0.sub.I !.sub.f =max{?O.sub.I !.sub.0 -?O.sub.

Abstract: A process and apparatus for regulating the concentration and distribution of oxygen in a single crystal silicon rod pulled from a silicon melt, optionally doped with antimony or arsenic, in accordance with the Czochralski method wherein an atmosphere is maintained over the melt. In batch embodiments of the process, the gas pressure of the atmosphere over the melt is progressively increased to a value in excess of 100 torr as the fraction of silicon melt solidified increases. In continuous embodiments of the process, the gas pressure of the atmosphere over the melt is maintained at or near a constant value in excess of 100 torr. The process and apparatus are further characterized in that a controlled flow of inert gas is used to remove vapors and particulate away from the surface of the rod and melt, resulting in the production of a single crystal silicon rod having zero dislocations.

Abstract: This invention provides a method for pulling a single crystal silicon whose diameter is more than 200 mm. The single crystal silicon pulled by the method of this invention has a desired oxygen concentration and a uniform oxygen concentration distribution along its longitudinal axis. In the process of this invention, the single crystal silicon and the quartz crucible are driven to rotate in reverse directions, and the rotation speed of the single crystal silicon is set within the range of 8 to 16 rpm and to be more than twice the rotating speed of the crucible. The rotation speed of the crucible is set to be at its minimum value during pulling a body portion which begins from the beginning end of the single-crystal body and terminates at a location apart from the beginning end within a distance of 10% of the total length of the single-crystal body. Subsequently, the rotation speed of the crucible is gradually raised and is set to no more than a maximum value of 8 rpm.

Abstract: A process of growing crystals in which the uniformity of the oxygen concentration is desirable. In the process, the upper part of the material in the crucible is heated to form a molten layer, and a solid layer is formed at its lower part, then a seed crystal is made to contact the surface of the molten layer, and pulled up to grow a crystal, while characteristically a magnetic field is applied to the molten layer. This method produces single crystals with a uniform distribution of oxygen concentration. Furthermore, this method produces single crystals at low cost and with a high productivity.

Abstract: A method for controlling oxygen-induced stacking faults (OISF) in a silicon crystal (12) grown according to the Czochralski silicon crystal growing technique includes the steps of forming a flared top portion (18) of the silicon crystal (12) to a predetermined diameter (20) and tapering (23) the silicon crystal (12) top portion (18) to produce a cylindrical portion (22) having a second predetermined diameter. The second predetermined diameter is smaller than the first predetermined diameter. Because of the inward taper (23) OISF concentrates in the flared top portion (18) of silicon crystal (12).

Abstract: Methods for quantifying, in near real-time, the amount of silicon oxide (SiO) volatilized from a pool of molten silicon such as a Czochralski silicon melt and present in the atmosphere over the melt are disclosed. A preferred method includes reacting a gas sample containing SiO withdrawn from the atmosphere over the molten silicon with a reactant to form a detectable reaction product, determining the amount of reaction product formed, and correlating the determined amount of reaction product to the amount of SiO present in the atmosphere. The quantification of SiO is used for monitoring and/or controlling the amount of oxygen in the molten silicon or the oxygen content in single crystal silicon being drawn from the molten silicon. A SiO reaction probe and a system using the probe for monitoring and/or controlling oxygen are also disclosed.

Abstract: A method for controlling oxygen precipitation (106) in a silicon crystal (12) grown according to the Czochralski silicon crystal growing technique which includes the steps of forming a cylindrical portion (22) of the silicon crystal (12) from a reservoir of molten silicon (24) according to the Czochralski silicon crystal growing technique. The method includes the steps of terminating the Czochralski silicon crystal growing technique by forming a first tapered portion (101) in silicon crystal (12) at a predetermined rate. A second tapered portion (102) includes a cascaded middle portion (108) that connects to the first tapered portion (101) and that concentrates oxygen precipitation (106) within cascaded middle portion (108) and away from the cylindrical portion (22) of silicon crystal (12). At least a third tapered portion (104) is formed for separating silicon crystal (12) from molten silicon (24).

Abstract: In a heat history initializing step, a heat treatment in performed in an atmosphere including at least one of hydrogen, helium, and argon while the temperature is increased in a range of 700.degree. C. to 1,000.degree. C. at a rate of 15.degree.-1,000.degree. C./min. In a controlled nuclei growing step, a heat treatment is performed in the above atmosphere while the temperature is kept constant in a range of 850.degree. C. to 980.degree. C. for 0.5-60 minutes.

Abstract: An apparatus and a method are provided for producing a silicon single crystal in an inert-gas flushed pulling chamber by pulling the single crystal from a melt by the Czochralski method. The method includes a) providing in the pulling chamber a first inner chamber and a second inner chamber, each of which is delineated by side, top and bottom boundaries; b) passing a first inert gas stream through the top boundary of the first inner chamber into the first inner chamber, which contains a heat shield, which is disposed around the single crystal, and a crucible containing the melt, and c) passing a second inert gas stream through the bottom boundary of the second inner chamber into the second inner chamber, which contains a heating device for heating the crucible, with the proviso that the first inert gas stream and the second inert gas stream are only able to mix, at the earliest, after leaving the inner chambers.

Abstract: System and method for determining the diameter of a silicon crystal being pulled from a silicon melt for controlling a silicon crystal growing apparatus. The melt has a surface with a meniscus which is visible as a bright ring adjacent the crystal. A camera generates an image pattern of a portion of the bright ring adjacent the crystal. Image processing circuitry detects a characteristic of the image pattern and defines an edge of the bright ring as a function of the detected characteristic. The image processing circuitry further defines a generally circular shape including the defined edge of the bright ring. The diameter of the crystal is then determined based on the diameter of the defined shape for use in controlling the crystal growing apparatus.

Abstract: The present invention is to manufacture a low hydrogen-concentration silicon crystal having less micro defects caused from oxygen precipitation generated during an annealing process. Particularly, a silicon crystal including hydrogen concentration lower than 0.55.times.10.sup.11 cm.sup.-3, where the hydrogen concentration dependency is small and the micro defect density is less, may be used for a substrate of semiconductor devices. The low hydrogen-concentration silicon substrate is manufactured by measuring the hydrogen concentrations in a silicon crystal and in a hydrogen-doped silicon crystal having a known hydrogen concentration, where both the silicon crystals have been annealed at an equal condition so as to generate thermal donors therein, and by comparing thus measured hydrogen concentrations.

Abstract: A method for controlling oxygen precipitation (106) in a silicon crystal (12) grown according to the Czochralski silicon crystal growing technique which includes the steps of forming a cylindrical portion (22) of the silicon crystal (12) from a reservoir of molten silicon (24) according to the Czochralski silicon crystal growing technique. The method includes the steps of terminating the Czochralski silicon crystal growing technique by forming a first tapered portion (101) in silicon crystal (12) at a predetermined rate. A second tapered portion (102) includes a cascaded middle portion (108) that connects to the first tapered portion (101) and that concentrates oxygen precipitation (106) within cascaded middle portion (108) and away from the cylindrical portion (22) of silicon crystal (12). At least a third tapered portion (104) is formed for separating silicon crystal (12) from molten silicon (24).

Abstract: Process for controlling the density of oxygen precipitate nucleation centers in single crystal silicon. In the process, the single crystal silicon is annealed at a temperature of at least about 350.degree. C. to cause the formation of oxygen precipitate nucleation centers in the single crystal silicon. During the annealing step, the single crystal silicon is heated (or cooled) to achieve a first temperature, T.sub.1, which is between about 350.degree. C. and about 500.degree. C. The temperature is then increased from T.sub.1 to a second temperature, T.sub.2, which is between about 500.degree. C. and about 750.degree. C. with the average rate of temperature increase from T.sub.1 to T.sub.2 being less than about 25.degree. C. per minute. The annealing is terminated at a point in time when the oxygen precipitate nucleation centers are capable of being dissolved by heat-treating the silicon at a temperature not in excess of about 1150.degree. C.

Abstract: This invention relates to the apparatus and the process for producing single crystals with little OSF generation and excellent dielectric strength of gate oxide films by adjusting the temperature gradient of the silicon single crystal in the direction of pulling. The apparatus is provided with a crucible which contains the melt of the single crystal material, a heating element which heats the melt, a pulling shaft to grow the single crystal, a protective gas inlet pipe, and a chamber which contains all above mentioned components. In addition, the apparatus is provided with a circular cylinder or a cylindrical shaped heat resistant and heat insulating component below the protective gas inlet pipe noted above.

Abstract: A monocrystal pulling apparatus according to the Czochralski technique, provided with a flow controller which guides a carrier gas supplied from the top of a pulling cheer to the surface of a melt of a material forming the monocrystal and exhausts the silicon oxide vaporizing from the surface of the melt to the outside of the pulling chamber and which surrounds the pulled monocrystal near the surface of the melt and is provided partially inside a crucible, wherein the flow controller has a tubular portion which has an outer diameter smaller than the inner diameter of the crucible and extends substantially perpendicularly along the direction of downward flow of the carrier gas, a constricted diameter portion which constricts in diameter from the bottom end of the tubular portion and forms a bottom gap with the pulled monocrystal, and an engagement portion which projects out from the top of the tubular portion and forms a top gap at the outer circumference of the tubular portion of the flow controller by suppor

Abstract: A method for fabricating semiconductor substrates with resistivity below 0.02 ohm-cm is provided. This low resistivity is achieved by doping a silicon melt with a phosphorus concentrations above 1.times.10.sup.18. The silicon melt is also doped with a germanium concentration that is 1.5 to 2.5 times that of the phosphorus concentration and a stress and dislocation free crystalline boule is grown. Phosphorus in high concentrations will induce stress in the crystal lattice due to the difference in the atomic radius of silicon atoms versus phosphorus atoms. Germanium compensates for the atomic radius mismatch and also retards the diffusion of the phosphorus as the diffusion coefficient remains relatively constant with a doping of 1.times.10.sup.18 to 1.times.10.sup.21 atoms per cm.sup.3. This will retard phosphorus from diffusing into an overlying epitaxial layer and retard other layers formed on the substrate from being auto-doped.

Abstract: The amount of Group-V element included in a melt 6 has the close relationship with the oxygen concentration of the melt 6. This relationship is utilized for controlling the oxygen concentration of a single crystal 8 at a high level. The content of Group-V element is calculated from the weight of the melt 6 gauged by a gravimeter 11 and compared with a preset value in a control unit 12. When the calculated content is smaller than the preset value, the control signal to additionally supply Group-V element to the melt 6 is outputted from the control unit 12 to a feeder 14. When the calculated content is larger than the preset value, the control signal to supply a raw material to the melt 6 is outputted to another feeder 13.

Abstract: The present invention is to manufacture a low hydrogen-concentration silicon crystal having less micro defects caused from oxygen precipitation generated during an annealing process. Particularly, a silicon crystal including hydrogen concentration lower than 0.55.times.10.sup.11 cm.sup.-3, where the hydrogen concentration dependency is small and the micro defect density is less, may be used for a substrate of semiconductor devices. The low hydrogen-concentration silicon substrate is manufactured by measuring the hydrogen concentrations in a silicon crystal and in a hydrogen-doped silicon crystal having a known hydrogen concentration, where both the silicon crystals have been annealed at an equal condition so as to generated thermal donors therein, and by comparing thus measured hydrogen concentrations.

Abstract: A process and an apparatus reduces the oxygen incorporation into a single crystal of silicon which is drawn by the Czochralski method. If a molding is immersed at least temporarily in the melt between the single crystal and the crucible wall during drawing of the single crystal, the oxygen content of the single crystal is reduced compared with the oxygen content of a single crystal which has been drawn without the use of the molding.

Abstract: A Si material mixed with Group-V element is melted in a crucible, and then held in a chamber filled with a rare gas at atmospheric pressure of 100 torr. or higher. A rare gas, e.g. Ar, Kr, Xe or Rn, having a large mass or the mixture of Ar with Kr, Xe or Rn may be used as atmospheric gas. The high-pressure atmosphere suppress the evaporation of oxides of Group-V elements from the Si melt, so that the Si melt can be maintained at a high oxygen concentration under a stable condition until the start of pulling operation.

Abstract: A solid layer is melted from the upper part thereof by the heat of a heater while the contact area between a molten liquid layer and an inner wall of a crucible is adjusted in a Double Layered CZ method, so that the eluting amount of oxygen from the crucible to the molten liquid layer is controlled. Accordingly, silicon single crystals of the low concentration of oxygen are produced.

Abstract: A method for controlling oxygen precipitation (106) in a silicon crystal (12) grown according to the Czochralski silicon crystal growing technique which includes the steps of forming a cylindrical portion (22) of the silicon crystal (12) from a reservoir of molten silicon (24) according to the Czochralski silicon crystal growing technique. The method includes the steps of terminating the Czochralski silicon crystal growing technique by forming a first tapered portion (101) in silicon crystal (12) at a predetermined rate. A second tapered portion (102) includes a cascaded middle portion (108) that connects to the first tapered portion (101) and that concentrates oxygen precipitation (106) within cascaded middle portion (108) and away from the cylindrical portion (22) of silicon crystal (12). At least a third tapered portion (104) is formed for separating silicon crystal (12) from molten silicon (24).

Abstract: A process and apparatus for growing a crysrtal by the Czochralski method, in which a melt is disposed in a crucible, partitioned into an outer annular portion and an inner cylindrical portion by an annular separation element which is open at its bottom, the open bottom being spaced from the bottom of the crucible. The separation element is rotated on its vertical axis and a crystal is pulled from the melt in the inner cylindrical portion by raising a crystal holder, which is also rotated, in the vertical direction. The melt required for growing the crystal flows from the outer annular portion to the inner cylindrical portion over the entire cross-section of the inner cylindrical portion at the bottom of the annular separation element.

Abstract: A method and apparatus for pulling single crystals from a melt of semicontor material, in which a monocrystalline seed crystal grows to form a single crystal, the seed crystal being dipped into the melt and raised in a controlled manner in the vertical direction with respect to the melt, while the melt forms a molten pool which is held on a support body only by the surface tension and by electromagnetic forces due to an induction coil. This method includes recharging the melt with semiconductor material in solid or liquid form during the growth of the single crystal.

Abstract: In an improved Czochralski process for growing silicon crystals, wherein a single-crystal silicon seed is pulled from a molten silicon source to grow the crystal therefrom, a pre-oxidized arsenic dopant is added to the molten silicon source to alter an electrical property of the grown crystal. The pre-oxidized arsenic dopant includes granular particles of metallic arsenic having a surface film of arsenic oxide, the surface film having a thickness of ten microns to one millimeter. After doping, the molten silicon source is moved from the grown crystal, and an applied temperature is increased to burn excess pre-oxidized dopant.

Abstract: A method of producing a silicon single crystal, in which a cylindrical partition is immersed in a molten pure silicon liquid or molten silicon liquid containing a Sb dopant within a crucible and the molten liquid inside the partition is pulled up from the crucible to produce the silicon single crystal, wherein an interval between a lower end of the partition and a crucible bottom is changed to control an oxygen concentration in the pulling-up silicon single crystal. The interval is reduced in the case where the oxygen concentration in the pulling-up silicon single crystal is to be increased while the interval is increased in the case where the oxygen concentration is to be reduced.

Abstract: A single silicon crystal wafer produced by the Czochvalski method and measuring not less than 100 mm in diameter, a single silicon crystal having low OSF density induced by oxidation, wherein regarding the local resistivity measured by the spread resistance method on the surface of said wafer subjected in advance to a heat treatment for extinction of oxygen donor, the proportion of the number of points of measurement registering errors exceeding .+-.1.0% of the mean value is not more than 35% of the total number of points of measurement, and regarding the distribution of oxygen concentration in solid solution in the wafer surface, the difference between the maximum and the minimum is not more than 2.0% of the maximum, and a method for production thereof.