A method for manufacturing a silicon single crystal according to a Czochralski method to manufacture an N-type silicon single crystal, including the steps of: seeding to bring a seed crystal into contact with a silicon melt in a crucible and thereafter, necking to pull the seed crystal to narrow a diameter thereof, wherein a dopant concentration in the silicon melt is predicted by a difference between a temperature at the seeding and a temperature at the necking, and resistivity of the single crystal to be pulled is controlled on the basis of the predicted dopant concentration in the silicon melt. A method for manufacturing a silicon single crystal can efficiently manufacture a silicon single crystal with a desired resistivity.

A method for producing a single crystal, wherein the space is adjusted to a predetermined distance by measuring a distance from a reference height position at a predetermined height above a melt surface to a lower end part of an in-furnace structure in a state wherein the in-furnace structure above the melt surface is installed in a pull chamber, obtaining a lower end part position error which is a difference between measured distance and a distance from the previously set reference height position to the lower end part of the in-furnace structure, obtaining a target distance from the melt surface to the reference height position by adding the lower end part position error and a distance from the reference height position to a melt surface position, and adjusting a distance from an initial position of the melt surface to the reference height position such that the target distance is attained.

A bismuth and magnesium co-doped lithium niobate crystal includes Li.sub.2CO.sub.3, Nb.sub.2O.sub.5, Bi.sub.2O.sub.3 and MgO, wherein the molar ratio of [Li] and [Nb] is 0.90-1.00, the molar percentage of Bi.sub.2O.sub.3 in the mixture is 0.25-0.80%, and the molar percentage of MgO in the mixture is 3.0-7.0%. The bismuth and magnesium co-doped lithium niobate crystal has enhanced photorefraction, improved photorefractive sensitivity, shortened holographic grating saturation writing time, and the photorefractive diffraction efficiency can reach up to 17%. The response time is only 170 ms, when the holographic storage experiment is carried out using 488 nm continuous laser. Therefore, this crystal can be used in the field of holographic imaging.

This invention provides a method for growing monocrystalline silicon by applying Czochralski method comprising forming a melt of silicon-containing materials in a crucible and pulling the melt for monocrystalline silicon growth, which is characterized by, the silicon-containing materials comprising a deuterium-implanted nitride-deposited silicon and a monocrystalline silicon, introducing a gas containing argon during formation of the melt, and, applying a magnetic field during the pulling step. This invention also provides a method for producing a wafer based on the above monocrystalline silicon.

A method for manufacturing a monocrystalline silicon with Czochralski process, including: providing polycrystalline silicon and dopant to quartz crucible in single crystal furnace and vacuumizing, melting the polycrystalline silicon under protective gas to obtain silicon melt; after temperature of the silicon melt is stable, immersing seed crystal into the silicon melt to start seeding, lifting a shield away from surface of the silicon melt to adjust distance between the shield and the silicon melt to first preset distance; after seeding, performing shouldering to pull the crystal to increase diameter of the crystal to preset width; starting constant-diameter body growth, lowering the shield towards the surface of the silicon melt to adjust the distance to second preset distance; after growth, entering a tailing stage during which the diameter of the crystal is reduced until the crystal is separated from the silicon melt; and cooling the crystal to obtain monocrystalline silicon.

In this photoelectric conversion element wherein group III-IV compound semiconductor single crystals containing zinc as an impurity are used as a substrate, the substrate is increased in size without lowering conversion efficiency. A heat-resistant crucible is filled with raw material and a sealant, and the raw material and sealant are heated, thereby melting the raw material into a melt, softening the encapsulant, and covering the melt from the top with the encapsulant. The temperature inside the crucible is controlled such that the temperature of the top of the encapsulant relative to the bottom of the encapsulant becomes higher in a range that not equal or exceed the temperature of bottom of the encapsulant, and seed crystal is dipped in the melt and pulled upward with respect to the melt, thereby growing single crystals from the seed crystal. Thus, a large compound semiconductor wafer that is at least two inches in diameter and has a low dislocation density of 5,000 cm.sup.−2 can be obtained, despite having a low average zinc concentration of 5×10.sup.17 cm.sup.−3 to 3×10.sup.18 cm.sup.−3, at which a crystal hardening effect does not manifest.

An embodiment provides a silicon single crystal growth method comprising the steps of: (a) allowing the shoulder of a single crystal to grow vertically; (b) allowing the shoulder to grow horizontally after the vertical growth; and (c) allowing the shoulder to grow in a downward convex shape after the horizontal growth of the shoulder, wherein the shoulder grows at a preset rate on the basis of the final diameter of the shoulder and the shoulder growth height according to steps (b) and (c).

Provided is a large diameter InP single crystal substrate having a diameter of 75 mm or more, which can achieve a high electrical activation rate of Zn over a main surface of the substrate even in a highly doped region having a Zn concentration of 5×10.sup.18 cm.sup.−3 or more; and a method for producing the same. An InP single crystal ingot is cooled such that a temperature difference of 200° C. is decreased for 2 to 7.5 minutes, while rotating the InP single crystal ingot at a rotation speed of 10 rpm or less, and the cooled InP single crystal ingot is cut into a thin plate, thereby allowing production of the InP single crystal substrate having an electrical activation rate of Zn of more than 85% over the main surface of the substrate even in a highly doped region having a Zn concentration of 5×10.sup.18 cm.sup.−3 or more.

In this photoelectric conversion element wherein group III-IV compound semiconductor single crystals containing zinc as an impurity are used as a substrate, the substrate is increased in size without lowering conversion efficiency. A heat-resistant crucible is filled with raw material and a sealant, and the raw material and sealant are heated, thereby melting the raw material into a melt, softening the encapsulant, and covering the melt from the top with the encapsulant. The temperature inside the crucible is controlled such that the temperature of the top of the encapsulant relative to the bottom of the encapsulant becomes higher in a range that not equal or exceed the temperature of bottom of the encapsulant, and seed crystal is dipped in the melt and pulled upward with respect to the melt, thereby growing single crystals from the seed crystal. Thus, a large compound semiconductor wafer that is at least two inches in diameter and has a low dislocation density of 5,000 cm.sup.−2 can be obtained, despite having a low average zinc concentration of 5×10.sup.17 cm.sup.−3 to 3×10.sup.18 cm.sup.−3, at which a crystal hardening effect does not manifest.

An embodiment provides a silicon single crystal growth method comprising the steps of: (a) allowing the shoulder of a single crystal to grow vertically; (b) allowing the shoulder to grow horizontally after the vertical growth; and (c) allowing the shoulder to grow in a downward convex shape after the horizontal growth of the shoulder, wherein the shoulder grows at a preset rate on the basis of the final diameter of the shoulder and the shoulder growth height according to steps (b) and (c).