Patent classifications
C30B15/36
PIEZOELECTRIC SINGLE CRYSTAL M3RE(PO4)3 AND THE PREPARATION METHOD AND APPLICATION THEREOF
A crystal is of a non-centrosymmetric structure and belongs to the −43 m point group of the cubic crystal system. M denotes an alkaline earth metal, which can be Ba, Ca, or Sr, and RE denotes a rare earth element, which can be Y, La, Gd, or Yb. The growth method of the M.sub.3RE(PO.sub.4).sub.3 crystal comprises steps as follows: (1) polycrystalline material synthesis: MCO.sub.3, RE.sub.2O.sub.3, and phosphorous compound are used as raw materials and blended according to the stoichiometric proportions; then, the phosphorous compound is further added to be excessive; the raw materials are sintered twice to obtain the M.sub.3RE(PO.sub.4).sub.3 polycrystalline material; (2) polycrystalline material melting; (3) Czochralski crystal growth. The M.sub.3RE(PO.sub.4).sub.3 crystal prepared by the invention is a high-quality single crystal.
PIEZOELECTRIC SINGLE CRYSTAL M3RE(PO4)3 AND THE PREPARATION METHOD AND APPLICATION THEREOF
A crystal is of a non-centrosymmetric structure and belongs to the −43 m point group of the cubic crystal system. M denotes an alkaline earth metal, which can be Ba, Ca, or Sr, and RE denotes a rare earth element, which can be Y, La, Gd, or Yb. The growth method of the M.sub.3RE(PO.sub.4).sub.3 crystal comprises steps as follows: (1) polycrystalline material synthesis: MCO.sub.3, RE.sub.2O.sub.3, and phosphorous compound are used as raw materials and blended according to the stoichiometric proportions; then, the phosphorous compound is further added to be excessive; the raw materials are sintered twice to obtain the M.sub.3RE(PO.sub.4).sub.3 polycrystalline material; (2) polycrystalline material melting; (3) Czochralski crystal growth. The M.sub.3RE(PO.sub.4).sub.3 crystal prepared by the invention is a high-quality single crystal.
Silicon-based molten composition and method for manufacturing silicon carbide single crystal using the same
A silicon-based molten composition according to an exemplary embodiment of the present invention is used in a solution growing method for forming silicon carbide single crystal, and is expressed in Formula 1 including silicon (Si), chromium (Cr), vanadium (V), and aluminum (Al).
Si.sub.aCr.sub.bV.sub.cAl.sub.d [Formula 1]
In Formula 1, a is equal to or greater than 0.4 and equal to or less than 0.9, b+c is equal to or greater than 0.1 and equal to or less than 0.6, c/(b+c) is equal to or greater than 0.05 and equal to or less than 0.95, and d is equal to or greater than 0.01 and equal to or less than 0.1.
Silicon-based molten composition and method for manufacturing silicon carbide single crystal using the same
A silicon-based molten composition according to an exemplary embodiment of the present invention is used in a solution growing method for forming silicon carbide single crystal, and is expressed in Formula 1 including silicon (Si), chromium (Cr), vanadium (V), and aluminum (Al).
Si.sub.aCr.sub.bV.sub.cAl.sub.d [Formula 1]
In Formula 1, a is equal to or greater than 0.4 and equal to or less than 0.9, b+c is equal to or greater than 0.1 and equal to or less than 0.6, c/(b+c) is equal to or greater than 0.05 and equal to or less than 0.95, and d is equal to or greater than 0.01 and equal to or less than 0.1.
SILICON SINGLE CRYSTAL GROWTH METHOD AND APPARATUS
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).
SILICON SINGLE CRYSTAL GROWTH METHOD AND APPARATUS
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).
Polycrystalline Silicon Material
A polycrystalline silicon material for producing silicon single crystal, containing a plurality of polycrystalline silicon chunks, in which assuming that a total concentration of donor elements present inside a bulk body of the polycrystalline silicon material is Cd1 [ppta], a total concentration of acceptor elements present inside the bulk body of the polycrystalline silicon material is Ca1 [ppta], a total concentration of the donor elements present on a surface of the polycrystalline silicon material is Cd2 [ppta], and a total concentration of the acceptor elements present on the surface of the polycrystalline silicon material is Ca2 [ppta], Cd1, Ca1, Cd2, and Ca2 satisfy a relation of 2 [ppta]≤(Cd1+Cd2)−(Ca1+Ca2)≤8 [ppta].
Polycrystalline Silicon Material
A polycrystalline silicon material for producing silicon single crystal, containing a plurality of polycrystalline silicon chunks, in which assuming that a total concentration of donor elements present inside a bulk body of the polycrystalline silicon material is Cd1 [ppta], a total concentration of acceptor elements present inside the bulk body of the polycrystalline silicon material is Ca1 [ppta], a total concentration of the donor elements present on a surface of the polycrystalline silicon material is Cd2 [ppta], and a total concentration of the acceptor elements present on the surface of the polycrystalline silicon material is Ca2 [ppta], Cd1, Ca1, Cd2, and Ca2 satisfy a relation of 2 [ppta]≤(Cd1+Cd2)−(Ca1+Ca2)≤8 [ppta].
Silicon single crystal growth method and apparatus
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).
Silicon single crystal growth method and apparatus
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).