Method of manufacturing semiconductor material from mayenite

Abstract

A method of preparation of semiconductor material. The method includes: adding an organic substance containing a benzene ring and dodecacalcium hepta-aluminate (12CaO.7Al.sub.2O.sub.3 or C12A7) to a test tube, and sealing the test tube; heating the test tube to a temperature of 200-300 C., and holding the temperature for 1 to 3 hours; and continuously heating the test tube to a temperature of 900-1300 C., and holding the temperature for 10-120 hours.

Claims

1. A method, comprising: (1) adding an organic substance containing a benzene ring and dodecacalcium hepta-aluminate (C12A7) to a test tube, and sealing the test tube; (2) heating the test tube to a temperature of 200-300 C., and holding the temperature for 1 to 3 hours; and (3) continuously heating the test tube to a temperature of 900-1300 C., and holding the temperature for 10-120 hours.

2. The method of claim 1, wherein the dodecacalcium hepta-aluminate is a monocrystalline or polycrystalline material.

3. The method of claim 2, wherein the polycrystalline material of the dodecacalcium hepta-aluminate is prepared as follows: weighing calcium nitrate tetrahydrate and aluminum nitrate nonahydrate according to a stoichiometric ratio thereof of 12 to 14; weighing urea which is three times a total stoichiometry of the calcium nitrate tetrahydrate and the aluminum nitrate nonahydrate, mixing and stirring the calcium nitrate tetrahydrate, the aluminum nitrate nonahydrate, and the urea with deionized water, to form a transparent solution; transferring the transparent solution to a corundum crucible, heating a muffle furnace to 500 C., calcining the corundum crucible in the muffle furnace for 2 hours, and cooling the muffle furnace, to yield polycrystalline C12A7 powders; and pressing the polycrystalline C12A7 powders into a tablet having a thickness of 0.5-0.8 mm under a pressure of 100-200 megapascal.

4. The method of claim 2, wherein the monocrystalline material of the dodecacalcium hepta-aluminate is prepared using a floating zone (FZ) method or Czochralski (CZ) method, and the Czochralski (CZ) method comprises: dissolving a polycrystalline C12A7 in a crystal grower, using platinum wire as a seed crystal and pulling out a crystal, allowing the crystal to grow, and cooling the crystal to room temperature in 30 to 50 hours to obtain a C12A7 monocrystalline block; and cutting the monocrystalline block into sheets having a thickness of about 0.8 mm.

5. The method of claim 1, further comprising degreasing and dehydroxylating the dodecacalcium hepta-aluminate prior to (1).

6. The method of claim 5, wherein degreasing and dehydroxylating the dodecacalcium hepta-aluminate comprises: heating the dodecacalcium hepta-aluminate to a temperature of 1100 C., holding the temperature for 15 hours, and cooling.

7. The method of claim 1, wherein calcium (Ca) and aluminum (Al) in the dodecacalcium hepta-aluminate is partially substituted by iron (Fe), magnesium (Mg) or rare-earth metal elements; the rare-earth metal elements are selected from europium (Eu), dysprosium (Dy), erbium (Er), holmium (Ho), and ytterbium (Yb), and a substitution ratio is 0 to 5% by mole; and the anion O.sup.2 in the dodecacalcium hepta-aluminate is replaced by H.sup., O.sup., OH.sup. or halogen ions, and the halogen ions are F.sup. or Cl.sup..

8. The method of claim 1, wherein a weight ratio of the organic substance containing a benzene ring to the dodecacalcium hepta-aluminate in the test tube is between 10:1 and 1:50.

9. The method of claim 1, wherein the test tube is a quartz test tube, a corundum test tube or a ceramic test tube, and the test tube is provided with a stopper.

10. The method of claim 1, wherein the organic substance containing a benzene ring is chlorobenzene, o-dichlorobenzene, bromobenzene, benzoic acid, phthalic acid, benzaldehyde, benzonitrile, anisole, benzenesulfonic acid, acetophenone, phenylacetamide, methyl benzoate, phenol, styrene, aniline, p-phenylenediamine, or a mixture thereof.

11. The method of claim 1, wherein a purity of the organic substance containing a benzene ring is not lower than an industrial grade.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a photograph of a C12A7 conductive material as described in the disclosure.

(2) FIG. 2 is a flow diagram of a method of manufacturing a semiconductor material as described in the disclosure. The first step is to prepare C12A7 polycrystalline and monocrystalline materials, as shown in F110. Generally, a polycrystalline C12A7 is prepared by self-propagating combustion method, and a monocrystalline C12A7 is prepared by Czochralski (CZ) method. The second step shown in F120 is the treatment of C12A7 material, in which the material is physically flaked. The third step shown in F130 is the treatment of C12A7 material with benzene series under high temperatures.

(3) FIG. 3 is a schematic diagram of a device for manufacturing a semiconductor material as described in the disclosure.

(4) FIG. 4 is an X-ray diffraction pattern of a polycrystalline sample as described in the disclosure.

(5) FIG. 5 is an X-ray diffraction pattern of a monocrystalline sample as described in the disclosure.

(6) FIGS. 6A-6D are scanning electron microscope (SEM) images of a C12A7 conductive material as described in the disclosure; specifically, FIG. 6A, FIG. 6B, FIG. 6C, FIG. 6D are microscopic topography of materials at magnifications of 3000, 10000, 5000, and 10000.

(7) In the drawings, the following reference numbers are used: 210, the hearth of the furnace; 220, flange; 225, barometer; 230, twist switch; 240, benzene series; 250, test tube; 260, C12A7 monocrystalline slices; 265, C12A7 polycrystalline tablets; 245, high-temperature-resistant ceramic fiber cotton; 270, wedge-shaped base.

DETAILED DESCRIPTION

Example 1

(8) A polycrystalline C12A7 semiconductor material is prepared as follows:

(9) (1) 30.0 g of calcium nitrate tetrahydrate, 55.6 g of aluminum nitrate nonahydrate, 49.59 g of urea and 200 mL of distilled water were placed in a 500 mL glass beaker, and then the beaker was heated to 80 C. while stirring. The solution was transferred to the corundum, and thus, the volume of the solution in the crucible was less than half of its volume. When the furnace was heated to 500 C., the crucible was placed in the furnace and calcined in an air atmosphere for 2 h to obtain a fluffy white sample. This was ground to a powder and detected as a polycrystalline C12A7 material via X-ray diffraction (XRD).

(10) (2) 0.2 g of C12A7 polycrystalline powder was placed in a mold with a diameter of 13 mm. The C12A7 tablets were formed under a pressure of 100 megapascal for 30 s. The tablets were then placed in a quartz test tube that was sealed and calcined at 1100 C. for 15 h to degrease and dehydroxylate the tablets.

(11) (3) The water absorbent paper was stuffed at the bottom of the quartz tube so that it absorbed 5 mL of o-dichlorobenzene without the overflow phenomenon. A small mass of high-temperature cotton was inserted at the top of the absorbent paper, and two slices of dehydroxylated C12A7 tablets were placed on the cotton. After the plug was inserted, the tube head was raised with a corundum wedge and then placed in the middle of the furnace. The temperature of the furnace was increased to 300 C. at a rate of 10 C./min and heated for 1 h. Subsequently, the temperature was increased to 1100 C. at a rate of 5 C./min, and a black conductive C12A7 material was obtained by natural cooling to room temperature after heat preservation for 90 h.

(12) FIG. 3 shows a schematic diagram of the device for manufacturing a type of semiconductor material of the present invention. Specifically, 240 denotes the benzene series; 250 denotes the test tube; 260 and 265 denote the C12A7 monocrystalline slices and polycrystalline tablets, respectively; 245 denotes high-temperature-resistant ceramic fiber cotton; 270 denotes a wedge-shaped base composed of ceramic or corundum material; 210 denotes the hearth of the furnace composed of corundum; 220 denotes the flange used to seal the furnace; 230 denotes the twist switch on the flange, through the exhaust vent interface on the flange (where opening switch 230 can pump out the gas in the furnace through a mechanical pump); and 225 denotes the barometer connected to the flange (and indicates the pressure inside the furnace).

Example 2

(13) In a manner similar to the method in Example 1, C12A7 polycrystalline conductive material was manufactured. However, the C12A7 polycrystalline powder corresponds to an anion doped material prepared via the method of self-propagating combustion. The specific methods are as follows: 29.1 g of calcium nitrate tetrahydrate, 0.423 g of calcium chloride, 55.6 g of aluminum nitrate nonahydrate, 49.59 g of urea and 200 mL of distilled water were placed in a 500-mL glass beaker, and the beaker was then heated to 80 C. while stirring. The solution was transferred to the corundum, and thus, the volume of the solution in the crucible was less than half of its volume. When the furnace was heated to 500 C., the crucible was placed in a furnace and calcined in an air atmosphere for 2 h to obtain a fluffy white sample that was ground to a powder and identified via XRD as a polycrystalline C12A7 material.

(14) Thus, a black conductive C12A7 material was obtained.

Example 3

(15) In a manner similar to the method in Example 1, C12A7 polycrystalline conductive material was manufactured. However, the C12A7 polycrystalline powder corresponds to an ion doped material prepared via the method of self-propagating combustion. The specific methods are as follows: 28.80 g of calcium nitrate tetrahydrate, 2.28 g of ytterbium(I) nitrate pentahydrate, 55.60 g of aluminum nitrate nonahydrate, 49.59 g of urea and 200 mL of distilled water were placed in a 500-ml glass beaker, and the beaker was then heated to 80 C. while stirring. The solution was transferred to the corundum, and thus, the volume of the solution in the crucible was less than half of its volume. When the furnace was heated to 500 C., the crucible was placed in a furnace and calcined in an air atmosphere for 2 h to obtain a fluffy white sample that was ground to a powder and identified via XRD as a polycrystalline C12A7 material.

(16) Thus, a black conductive C12A7 material was obtained.

Example 4

(17) In a manner similar to the method in Example 1, C12A7 polycrystalline conductive material was manufactured. However, in (3), the benzene series corresponded to 3 g of benzenic acid, and the heat preservation time at 1100 C. was 100 h.

(18) Thus, a black conductive C12A7 material was obtained.

Example 5

(19) In a manner similar to the method in Example 1, C12A7 polycrystalline conductive material was manufactured. However, in (3), the benzene series corresponded to 5 g of benzenesulfonic acid, and the heat preservation time at 1100 C. was 60 h.

(20) Thus, a black conductive C12A7 material was obtained.

Example 6

(21) In a manner similar to the method in Example 1, C12A7 polycrystalline conductive material was manufactured. However, in (3), the benzene series was 2 g of p-phenylenediamine, and the heat preservation time at 1100 C. was 120 h.

(22) Thus, a black conductive C12A7 material was obtained.

Example 7

(23) A monocrystalline C12A7 semiconductor material is prepared as follows:

(24) (1) The polycrystalline C12A7 prepared by Example 1 was added to the iridium crucible and compacted to exclude several air pores. The iridium crucible was placed in a double mullite insulation cover; thus, it was in the center of the insulation cover and coincided with the center of the iridium crucible. The furnace was subsequently sealed, and the gas in the furnace was evacuated until the degree of vacuum reached 10.sup.3 Pa. The oxygen was inflated such that it occupied 0.5% of the volume content of the nitrogen and oxygen mixed gas, and the temperature was increased to 1200 C. to remove volatiles. Subsequently, the temperature was increased to 1400 C., and the powder was melted and heated for 2 h to ensure the uniformity of the melting solution. Subsequently, the temperature was decreased to 1390 C. to crystallize the C12A7 monocrystalline. The first preparation took platinum silk as the seed, and the crystal was pulled from the melt at a rate of 1.0-1.5 mm/h at a low speed of 10 to 20 rad/min. When the growth process was completed, the growing crystals were gradually cooled to room temperature within 30-50 h to avoid the formation of cracks due to thermal stress. The prepared material was identified via XRD as C12A7.

(25) (2) Obtained bulk monocrystalline material were cut into slices with a thickness of 0.8 mm by using a diamond wheel saw. The monocrystalline slices were placed in a quartz tube, and the samples were then dehydroxylated by heating at 1100 C. for 15 h.

(26) (3) A piece of absorbent paper was plugged into the bottom of the corundum test tube to absorb 5-mL bromobenzene without spillage. A small mass of high temperature cotton was inserted at the top of the absorbent paper, and two slices of dehydroxylated C12A7 tablets were placed on the cotton. After the plug was inserted, the tube head was raised with a corundum wedge and placed in the middle of the furnace. The temperature of the furnace was increased to 300 C. at a rate of 10 C./min and heated for 0.5 h. Subsequently, the temperature was increased to 1100 C. at a rate of 5 C./min. After heat preservation for 50 h, a black conductive C12A7 material was obtained via natural cooling to room temperature.

Example 8

(27) In a manner similar to the method in Example 7, C12A7 monocrystalline conductive material was manufactured. However, the FZ method was adopted for the preparation of C12A7 monocrystalline. The specific methods are as follows: first, the polycrystalline C12A7 powder prepared by Example 1 was ground into fine powder. The powder was placed in a rubber tube and compressed under a hydrostatic pressure of 300 megapascal to form a rod shape and subsequently sintered at 1350 C. in an oxygen atmosphere for 24 h to obtain a semitransparent feed rod. An atmosphere of 2% O.sub.2/98% N.sub.2 was prepared with a gas flow rate of 100 mL/min. The rod with the seed of <100> crystal direction attached to the top surface was placed in the furnace, and the feed rod was placed such that its bottom was close to the seed. The halogen lamps were concentrated around the bottom of the feed rod. When the irradiated part of the rod was melted, the upper rod was pulled down and attached to the crystal. The feed and seed rods were counter-rotated at 10 rpm at a speed of 1.0 mm/h. The grown crystal was cut from the rod and slowly cooled to room temperature for 24 h.

(28) Thus, a black conductive C12A7 material was obtained.

Example 9

(29) In a manner similar to the method in Example 7, the monocrystalline C12A7 semiconductor material was manufactured. However, the polycrystalline C12A7 used to prepare the monocrystalline material via the CZ method in (1) corresponded to a material doped with halogen ions as prepared in Example 2.

(30) Thus, a black conductive C12A7 material was obtained.

Example 10

(31) In a manner similar to the method in Example 7, the monocrystalline C12A7 semiconductor material was manufactured. However, the polycrystalline C12A7 used to prepare the monocrystalline material via the CZ method in (1) corresponded to a material doped with rare earth metal ions as prepared in Example 3.

(32) Thus, a black conductive C12A7 material was obtained.

Example 11

(33) In a manner similar to the method in Example 8, the monocrystalline C12A7 semiconductor material was manufactured. However, the polycrystalline C12A7 used for preparing the monocrystalline material via the FZ method in (1) corresponded to a material doped with halogen ions prepared in Example 2.

(34) Thus, a black conductive C12A7 material was obtained.

Example 12

(35) In a manner similar to the method in Example 8, the monocrystalline C12A7 semiconductor material was manufactured. However, the polycrystalline C12A7 used to prepare the monocrystalline material via the FZ method in (1) corresponded to a material doped with rare earth metal ions as prepared in example 3.

(36) Thus, a black conductive C12A7 material was obtained.

Example 13

(37) In a manner similar to the method in Example 7, the monocrystalline C12A7 semiconductor material was manufactured. However, in (3), the benzene series corresponded to 3 mL of methyl benzoate, and the heat preservation time at 1000 C. was 90 h.

(38) Thus, a black conductive C12A7 material was obtained.

Example 14

(39) In a manner similar to the method in Example 7, the monocrystalline C12A7 semiconductor material was manufactured. However, in (3), the benzene series corresponded to 5 g of phenylacetamide, and the heat preservation time at 1100 C. was 120 h.

(40) Thus, a black conductive C12A7 material was obtained.

(41) The information on the type of benzene series, high-temperature treatment conditions, and electron density of the prepared product in the examples of the present invention are shown in Table 1, wherein the electron density is measured by the Hall Effect measurement system.

(42) TABLE-US-00001 TABLE 1 Summary of information for the examples Mass ratio of Treatment C12A7 to temperature Treatment Electron density Example Benzene series benzene series ( C.) Time (h) (cm.sup.3) 1 o-dichlorobenzene 1:16 1100 90 7.3 10.sup.19 2 o-dichlorobenzene 1:16 1100 90 6.9 10.sup.19 3 o-dichlorobenzene 1:16 1100 90 7.2 10.sup.19 4 benzenic acid 1:7.5 1100 100 5.7 10.sup.19 5 benzenesulfonic 1:12.5 1100 60 4.3 10.sup.19 acid 6 p-phenylenediamine 1:5 1100 120 3.1 10.sup.19 7 bromobenzene 1:19 1100 50 1.2 10.sup.20 8 bromobenzene 1:19 1100 50 1.2 10.sup.20 9 bromobenzene 1:19 1100 50 9.8 10.sup.19 10 bromobenzene 1:19 1100 50 1.0 10.sup.20 11 bromobenzene 1:19 1100 50 1.0 10.sup.20 12 bromobenzene 1:19 1100 50 1.1 10.sup.20 13 methyl benzoate 1:8 1000 90 9.3 10.sup.19 14 phenylacetamide 1:5 1100 120 1.9 10.sup.20

(43) It will be obvious to those skilled in the art that changes and modifications may be made, and therefore, the aim in the appended claims is to cover all such changes and modifications.