Patent classifications
C30B15/203
EPITAXIAL SILICON WAFER
A method of manufacturing an epitaxial silicon wafer that includes growing a silicon single crystal ingot doped with a boron concentration of 2.710.sup.17 atoms/cm.sup.3 or more and 1.310.sup.19 atoms/cm.sup.3 or less by the CZ method; producing a silicon substrate by processing the silicon single crystal ingot; and forming an epitaxial layer on a surface of the silicon substrate. During growing of the silicon single crystal ingot, the pull-up conditions of the silicon single crystal ingot are controlled so that the boron concentration Y (atoms/cm.sup.3) and an initial oxygen concentration X (10.sup.17 atoms/cm.sup.3) satisfy the expression X4.310.sup.19Y+16.3.
METHODS FOR PRODUCING A SILICON INGOT THAT INVOLVE MONITORING A MOVING AVERAGE OF THE INGOT NECK PULL RATE
Methods for producing monocrystalline silicon ingots in which the pull rate during neck growth is monitored are disclosed. A moving average of the pull rate may be calculated and compared to a target moving average to determine if dislocations were not eliminated and the neck is not suitable for producing an ingot main body suspended from the neck.
INGOT GROWTH CONTROL DEVICE AND CONTROL METHOD THEREOF
The present invention relates to an ingot growth control device capable of quickly and accurately controlling a diameter of an ingot during an ingot growing process and improving quality of the ingot, and a control method thereof.
In the ingot growth control device and a control method thereof according to the present invention, when an input unit provides diameter data obtained by filtering a diameter measurement value of an ingot, a diameter controller reflects the diameter data to control a pulling speed of the ingot, while a temperature controller reflects the diameter data to control power of a heater.
METHOD FOR PULLING A SINGLE CRYSTAL COMPOSED OF SEMICONDUCTOR MATERIAL FROM A MELT CONTAINED IN A CRUCIBLE
Single crystal semiconductor ingots are pulled from a melt contained in a crucible by a method of controlling the pulling the single crystal in a phase in which an initial cone of the single crystal is grown until a phase in which the pulling of a cylindrical section of the single crystal is begun, by measuring the diameter Dcr of the initial cone of the single crystal and calculating the change in the diameter dDcr/dt; pulling the initial cone of the single crystal from the melt at a pulling rate vp(t) from a point in time t1 until a point in time t2, starting from which the pulling of the cylindrical section of the single crystal in conjunction with a target diameter Dcrs is begun, wherein the profile of the pulling rate vp(t) from the point in time t1 until the point in time t2 during the pulling of the initial cone is predetermined by means of an iterative computation process.
Silicon single crystal manufacturing method
A silicon single crystal manufacturing method in which the distance between the heat shield and the melt level of the melt can be regulated in a high precision. The real image includes at least the circular opening of the heat shield provided in such a way that the heat shield covers a part of the melt level of the silicon melt. The mirror image is a reflected image of the heat shield on the surface of the silicon melt. Based on the distance between the obtained real image and the mirror image, the melt level position of the silicon melt is computed, and the distance between the heat shield and the melt level position is regulated.
SOLID ELECTROLYTE MATERIAL AND ALL SOLID LITHIUM ION SECONDARY BATTERY
There are provided a solid electrolyte material having high density and ion conductivity, and an all solid lithium ion secondary battery using the solid electrolyte material. The solid electrolyte material has a garnet-related structure which has a chemical composition represented by Li.sub.7-x-yLa.sub.3Zr.sub.2-x-yTa.sub.xNb.sub.yO.sub.12 (0x0.8, 0.2y1, and 0.2x+y1) and relative density of 99% or greater, and belongs to a cubic system. The solid electrolyte material has lithium ion conductivity which is equal to or greater than 1.010.sup.3 S/cm. The solid electrolyte material has a lattice constant a which satisfies 1.28 nma1.30 nm, and has a lithium ion which occupies only two or more 96h sites in a crystal structure. The all solid lithium ion secondary battery includes a positive electrode, a negative electrode, and a solid electrolyte. The solid electrolyte includes the solid electrolyte material.
Method for pulling a cylindrical crystal from a melt
A method for pulling a cylindrical crystal from a melt by a crystal pulling unit includes measuring an actual value of a diameter of the crystal at a surface of the melt, comparing the actual value with a setpoint value for the diameter of the crystal, and setting a height of the annular gap as a function of a deviation between the actual value and the setpoint value using a first controller which has a first readjustment time.
Process for preparing ingot having reduced distortion at late body length
A method for growing a single crystal silicon ingot by the Czochralski method having reduced deviation in diameter is disclosed.
A METHOD OF FABRICATING A TURBINE ENGINE PART
A method of fabricating a turbine engine part, the method including fabricating an ingot out of ceramic material of eutectic composition by performing the Czochralski process including putting a seed of the ingot that is to be obtained into contact with a molten bath of a mixture of eutectic composition in order to initiate the formation of the ingot on the seed, the mixture including at least two ceramic compounds; drawing the ingot from the molten bath while imposing on the ingot that is being formed a drawing speed less than or equal to 10 mm/h together with rotation at a speed of rotation less than or equal to 50 rpm; and machining the ingot as fabricated in this way in order to obtain the turbine engine part.
VACANCY-RICH SILICON FOR USE WITH A GALLIUM NITRIDE EPITAXIAL LAYER
A manufacturing process is described to evaluate and select raw semiconductor wafers in preparation for epitaxial layer formation. The manufacturing process first produces a single crystal ingot during which a seed pulling velocity and temperature gradient are closely controlled. The resulting ingot is vacancy-rich with relatively few self-interstitial defects. Selected wafers can advance to a high-temperature nitridation annealing operation that further reduces the number of interstitials while increasing the vacancies. Substrates characterized by a high vacancy density can then be used to optimize an epitaxial layer deposition process.