WO2012055195A1

WO2012055195A1 - Quartz glass crucible and manufacturing method thereof

Info

Publication number: WO2012055195A1
Application number: PCT/CN2011/071180
Authority: WO
Inventors: 王春来; 周勇; 渥美崇
Original assignee: 杭州先进石英材料有限公司
Priority date: 2010-10-27
Filing date: 2011-02-22
Publication date: 2012-05-03
Also published as: CN102453956B; CN102453956A

Abstract

Disclosed are a quartz glass crucible and a method for manufacturing the same. The basal body of the crucible is coated with a transparent coating layer on its inner surface and the theoretical thickness of the layer is 50-500μm. The transparent coating layer is prepared by melting quartz sand doped with an alkali earth metal element which may be Mg, Ba, Sr or Ca. The alkali earth metal element is from barium oxide, a base of the alkali earth metal, a salt of the alkali earth metal or a mixture of a base of the alkali earth metal and a salt of the alkali earth metal in any ratio. Based on the quartz sand doped with the alkali earth metal element, the weight percentage of the alkali earth metal element is 400-2000ppm. The quartz crucible exhibits a longer durability, and it is not easy for the transparent coating layer on the inner surface to drop off and exfoliate when the crucible being used, which can produce no bad effect on the process of pulling the crystal. The dislocation-free proportion in grown silicon single crystal is large and the effect of pulling the crystal is excellent.

Description

(1) Technical field

The present invention relates to a quartz glass crucible, particularly a quartz glass crucible for use in the production of single crystal silicon by a pulling method, and a method of preparing the quartz glass crucible.

(2) Background technology

Quartz crucible is widely used as a container for holding polycrystalline silicon in the process of straight-drawing single crystal silicon. Therefore, quartz crucible as a direct contact with single crystal silicon material determines the key factor for the smooth production of single crystal silicon. One of the main causes of crystal pulling failure in the process of producing single crystal silicon by the Czochralski method is that the cristobalite formed on the inner surface of the quartz glass crucible is removed into the molten silicon melt.

At present, in the method for solving this problem, a crystallization promoter containing an alkaline earth metal is often applied to the inner surface of the crucible, so that in the early stage of the single crystal drawing, a dense cristobalite crystal layer is formed on the inner surface of the crucible to suppress the falling off. For example, Chinese Patent No. 03108420 is coated with a metal oxide coating on all or part of the side of the crucible; Chinese Patent No. 02155413.8 uses a method of coating a crystallization promoter on the surface of the crucible, and then firing the coating at a high temperature. on.

However, among these coating methods, there are the following problems:

(1) Since the adhesion between the coating on the inner surface of the crucible and the inner surface of the crucible is weak, the coating is liable to fall off during transportation and use, so that the coating does not have the effect it should have, and even causes a reaction; (2) Since these coatings have weak adhesion, they are very easy to be washed out during the washing process, and in particular, the requirements for pickling are not satisfied;

(3) The process is carried out after the completion of the production of the crucible, the process flow is long, the operation is complicated, and there is a risk that the quality of the crucible is seriously affected by secondary pollution.

U.S. Patent No. 6,641,663 B2 discloses the use of quartz sand doped with Ba element to make the inner layer of the crucible. Although the above problems are solved, the content of Ba in the inner layer of the crucible is low (5~). 150ppm), the inner layer of the crucible is thicker (0.2~1.0mm). The inventors have found in the experiment that the quartz glass crucible is prepared according to the method disclosed in the patent US 6,641,663 B2. Due to the low content of the Ba element in the inner layer, the obtained crucible is likely to cause the cristobalite crystal layer in the process of drawing the single crystal. The inner surface of the crucible is unevenly distributed. In order to ensure the crystal pulling effect, it is necessary to increase the thickness of the inner layer of the crucible, and the increase of the thickness of the inner layer may cause an adverse effect such as excessive thickness of the cristobalite layer, and it is obvious that the increase of the thickness of the inner layer increases the amount of the inner quartz sand. , increase costs.

(3) Invention content

The purpose of the present invention is to provide a quartz glass crucible and a preparation method thereof for solving the problem that the quartz crystal layer is peeled off on the inner surface and the uneven distribution of the cristobalite crystal layer or the cristobalite crystal layer is thick during the use. The problem of crystals having adverse effects.

The technical solution adopted by the invention is:

A quartz glass crucible comprising a crucible base, characterized in that the inner surface of the crucible base of the quartz glass crucible is coated with a transparent coating having a theoretical thickness of 50 to 500 μm, and the transparent coating is Alkaline earth metal element Prepared by quartz sand, which is natural quartz sand, synthetic quartz sand or a mixture of the two in any proportion, preferably synthetic quartz sand, the alkaline earth metal element refers to magnesium element, barium element, barium element or calcium An element, preferably a cerium element, derived from a mixture of cerium oxide, an alkaline earth metal base, an alkaline earth metal salt or an alkaline earth metal base and an alkaline earth metal salt in an arbitrary ratio, the alkaline earth metal element-doped quartz The mass content of the alkaline earth metal element in the sand is 400 to 2000 ppm, and the inner surface refers to the inner surface of the bottom of the base of the base, the inner surface of the wall of the base of the base or the entire inner surface of the base of the base.

The alkali earth metal base is one or a mixture of two or more of the following: magnesium hydroxide, barium hydroxide, barium hydroxide or calcium hydroxide, preferably barium hydroxide.

The alkaline earth metal salt is an alkaline earth metal inorganic salt and/or an alkaline earth metal organic salt. The alkaline earth metal inorganic salt is one or a mixture of two or more of the following: MeX _n , n is 1 or 2, wherein Me is Mg ²⁺ , Ba ²⁺ , Sr ²⁺ or Ca ²⁺ , and X is F -, Cl\ COO\ CH ₃ COO\ C ₂ H ₅ COO\ C0 ₃ ² \ Si0 ₃ ^2- or C ₂ 0 ₄ ^2- ; X is F -, Cl\ COO\ CH ₃ COO\ C ₂ H ₅ COO - when n = 2; when X is C0 ₃ ^2- , Si0 ₃ ^2- or C ₂ 0 ₄ ^2- , n = l. The alkaline earth metal organic salt is one or a mixture of two or more of the following: (R) ₂ M , wherein M is Mg, Ba, Sr or Ca, and R is C _m H _2m+1 COO, m=3~ An integer of 8.

The transparent coating has a theoretical thickness of 50 to 500 μm, preferably 50 μm to 100 μm. According to the thickness b of the transparent coating and the area S of the inner surface to be coated, the desired doping can be calculated according to the formula m=KxSxbxp. The mass amount m of the alkaline earth metal element quartz sand, wherein K is a different size diameter 坩埚 empirical coefficient, K = 1.5~2.0, ρ is the density of the quartz sand doped with the alkaline earth metal element, and then melted to obtain the transparent coating . When calculating according to the formula m=KxSxbxp, each parameter unit must be unified. The P of the present invention is a normal density of quartz sand doped with an alkaline earth metal element before high temperature melting, and the density of the quartz sand doped with an alkaline earth metal element is usually increased after melting, in order to make the transparent coating obtained by actual melting. The thickness of the layer is consistent with the thickness of the intended transparent coating. When calculating the mass m of the quartz sand doped with the alkaline earth metal element, the quartz sand doped with the alkaline earth metal element after melting is compared to the quartz sand before the melting. The multiple of the density increase is also reflected in the coefficient K. The transparent coating layer is formed by using a crucible mold to prepare a quartz glass crucible base body, and after the base material is melt-molded, a high current is applied to the electrode on the crucible mold, thereby forming a high temperature instantaneously in the mold. The arc of the state (greater than 2000 ° C) is then uniformly introduced into the quartz sand doped with an alkaline earth metal element, and after being melted at a high temperature, it is coated on the inner surface of the quartz glass crucible base to obtain the transparent coating.

More specifically, the bismuth matrix of the quartz glass crucible is obtained by melting natural quartz sand.

The mass content of the alkaline earth metal element in the quartz sand doped with the alkaline earth metal element is preferably 800 ppm to 1200 ppm.

More specifically, the quartz sand doped with an alkaline earth metal element can be obtained by the following method

3\: a mixture of cerium oxide, an alkaline earth metal base, an alkaline earth metal salt or an alkaline earth metal base and an alkaline earth metal salt in an arbitrary ratio to a solution having a mass percentage of 0.01 to 50%, and added to the quartz sand, The quartz sand is natural quartz sand, synthetic quartz sand or a mixture of the two in any ratio, and is thoroughly stirred and mixed, and then dried at 50 to 1000 ° C for 1 to 10 hours (preferably 200 to 300 ° C for 2 to 5 drying). In the hour, the quartz sand doped with an alkaline earth metal element is obtained, and the mass content of the alkaline earth metal element in the quartz sand is 400 to 2000 ppm. The solution is an aqueous solution or an organic solution. More specifically, the mixture of the cerium oxide, the alkaline earth metal alkali, the alkaline earth metal inorganic salt or the alkaline earth metal alkali and the alkaline earth metal inorganic salt is generally only soluble in water to form an aqueous solution; The alkaline earth metal organic salt is usually only dissolved in an organic solvent to form an organic solution, and the organic solvent is one or a mixture of two or more of the following:

The alcohol of C1-C5, the ester of C2~C8, the thiol-substituted benzene of C7-C11, the organic solvent is preferably one or a mixture of two or more of the following: methanol, ethanol, 1-propanol, 2-propanol, 1 - Butanol, isobutanol, 1-pentanol, 2-pentanol, 2-methyl-2-pentanol, isoamyl alcohol, toluene, xylene, ethyl acetate, most preferably toluene or ethyl acetate.

The prepared solution is added to the quartz sand, thoroughly stirred and mixed, and then dried at 50-1000 ° C (preferably 200-300 ° C) for 1 to 10 hours, which can be carried out multiple times to make the alkaline earth metal element The mass content of the quartz sand can be 400~2000ppm. When the operation is repeated, the solution may be added in the same solution, divided into several times, or may be added in different portions, and dried in stages, and finally the quality of the alkaline earth metal element in the quartz sand. The content is 400~2000ppm. Particularly, when the alkaline earth metal element is derived from an alkali, an alkaline earth metal organic salt, an alkaline earth metal inorganic salt or an alkaline earth metal organic salt, an alkaline earth metal alkali or an alkaline earth metal inorganic salt mixed with an alkaline earth metal organic salt and an alkaline earth metal, the alkaline earth metal organic The salt is dissolved in an organic solvent to form an organic solution, and the alkali, alkaline earth metal inorganic salt or alkaline earth metal alkali or alkaline earth metal inorganic salt of the alkaline earth metal is dissolved in water to form an aqueous solution, and the organic solution and the aqueous solution must be separately operated. . This should be a processing method well known to those skilled in the art.

More specifically, the quartz glass crucible of the present invention is obtained by the following method:

(1) a base of cerium oxide, an alkaline earth metal, a salt of an alkaline earth metal or an alkali earth metal Mixing a mixture with an alkaline earth metal salt in an arbitrary ratio to prepare a solution having a mass percentage of 0.01 to 50%, and adding it to quartz sand, which is natural quartz sand, synthetic quartz sand or a mixture of the two in any ratio. Mix well and then dry at 50~1000 °C (preferably 200-300 °C) for 1~10 hours to obtain quartz sand doped with alkaline earth metal elements. The mass content of alkaline earth metal elements in quartz sand is 400. ~2000 ppm; the alkali earth metal base is one or a mixture of two or more of the following: magnesium hydroxide, barium hydroxide, barium hydroxide or calcium hydroxide, preferably barium hydroxide.

The alkaline earth metal salt is an alkaline earth metal inorganic salt and/or an alkaline earth metal organic salt. The alkaline earth metal inorganic salt is one or a mixture of two or more of the following: MeX _n , n is 1 or 2, wherein Me is Mg ²⁺ , Ba ²⁺ , Sr ²⁺ or Ca ²⁺ , and X is F -, Cl\ COO\ CH ₃ COO\ C ₂ H ₅ COO\ C0 ₃ ² \ Si0 ₃ ^2- or C ₂ 0 ₄ ^2- ; X is F -, Cl\ COO\ CH ₃ COO\ C ₂ H ₅ COO - when n = 2; when X is C0 ₃ ^2- , Si0 ₃ ^2- or C ₂ 0 ₄ ^2- , n = l. The alkaline earth metal organic salt is one or a mixture of two or more of the following: (R) ₂ M , wherein M is Mg, Ba, Sr or Ca, and R is C _m H _2m+1 COO, m=3~ An integer of 8;

(2) The natural quartz sand is placed in a rotating boring mold, and the natural quartz sand is formed into a braid shape under the action of centrifugal force, and then a high current is applied to the electrode above the enamel mold to form an arc at a high temperature of 2000 ° C or higher, which is slow. The natural quartz sand is melted and formed into a ruthenium matrix. After the ruthenium matrix is melt-formed, the alkaline earth metal-doped quartz sand obtained in the step (1) is uniformly introduced into the ruthenium matrix at a rate of 50 to 100 g/min. The surface, the inner surface is the bottom inner surface of the base of the base, the inner surface of the wall of the base of the base or the entire inner surface of the base of the base. After the completion of the feeding and the completion of the melting, it is taken out after cooling to obtain the quartz glass crucible. Mass amount of quartz sand doped with alkaline earth metal elements m is calculated by estimating the thickness b of the transparent coating and the area S of the inner surface of the coating to be applied according to the formula m=KxSxbxp, where K is an empirical coefficient of different size diameter K, K=1.5~2.0, ρ is doped with alkaline earth The density of the quartz sand of the metal element, the thickness b of the intended transparent coating layer is 50 to 500 μm. In the step (1), the alkali earth metal base is preferably barium hydroxide; the alkaline earth metal inorganic salt is preferably barium carbonate or barium silicate, and the alkaline earth metal organic salt is preferably barium stearate or barium octylate. .

The quartz glass crucible provided by the invention has a uniform density in the inner surface of the crucible in the early stage of the single crystal drawing because the transparent coating on the inner surface of the crucible is doped with an alkaline earth metal element in the high temperature process of drawing the single crystal silicon. As a result of the cristobalite layer, a silicon single crystal having a high dislocation-free ratio can be obtained.

Therefore, the beneficial effects of the present invention are mainly embodied in:

(1) Since the transparent coating adhered to the inner surface of the quartz glass crucible is formed by uniformly introducing quartz sand into the inner surface of the crucible during the melting process of the arc-forming crucible, it has on the inner surface of the crucible Better uniform distribution.

(2) The quartz crucible of the present invention can produce a thin inner surface transparent coating by increasing the content of alkaline earth metal elements in the transparent layer on the inner surface, and the thinnest can be 50 μm, and the thin inner surface transparent coating can prevent The occurrence of defects such as the falling of the cristobalite crystal layer or the molten silicon into the cristobalite crystal layer during the crystal pulling process, and the uniform distribution of the cristobalite crystal layer on the inner surface of the crucible facilitates the smooth progress of the crystal pulling.

(3) The quartz glass crucible provided by the invention has high durability, and the transparent coating on the inner surface is not easy to be peeled off and peeled off during the use, and the phenomenon of adversely affecting the crystal pulling process is caused. The wrong proportion is high and the crystal pulling effect is good. (4) After the quartz glass crucible produced by the method of the present invention is subjected to pickling and high-pressure water washing, the inner surface clear coating is still present.

(5) Since the method of the present invention is an inner surface coating realized in the melting process of quartz glass crucible, the preparation method of the crucible is simple in operation and the production process is short.

(6) The entire quartz glass crucible production process is fully automated, achieving uniformity of mass production.

(4) Description of the drawings

Fig. 1 is a cross-sectional view of a quartz glass crucible prepared in Example 1, and the reference numeral 1 is referred to as a transparent coating.

Figure 2 shows the use of the quartz glass crucible prepared in Example 1 in a crystal pulling environment.

Fig. 3 shows the quartz glass crucible obtained in Example 1 after use in a crystal pulling environment.

(5) Specific implementation methods

The present invention will be further described below in conjunction with specific embodiments, but the scope of protection of the present invention is not limited thereto:

Preparation method of quartz sand doped with alkaline earth metal element strontium: Weigh a certain mass of a compound containing alkaline earth metal element cerium, dissolve it in a solvent to prepare a solution, and then add the solution to quartz sand, stir well and mix well. Drying, quartz sand containing alkaline earth metal element lanthanum can be obtained.

According to the above method, quartz sand containing alkaline earth metal element cerium is prepared, and the corresponding compound and solvent corresponding to the alkaline earth metal element and the corresponding amount are as follows: Table 1 Containing alkaline earth quartz sand

Formulated

Formulated metal element formulated to dissolve quartz sand type 钡 element dry temperature drying solvent solution

The concentration and amount of the compound (#c) (h) (g)

(ppm)

Synthetic quartz sand

a Isooctanoate 甲苯 Toluene 1% 50 400 300 5

404.0g

Synthetic quartz sand

b 正 n-butyric acid toluene 5% 20 400 300 5

1103. lg

Natural quartz sand

And synthetic quartz

c n-butyric acid yttrium toluene 5% sand mixed sand 20 600 300 5

( 1 : 1 )

735.2g

Isooctanoate

And stearic acid

Dimethyl synthetic quartz sand

d 钡 mass ratio 30% 10 800 300 5 benzene 971.5g

1: 1 mix

Compound

Dimethyl synthetic quartz sand

e bismuth isovalerate 5% 50 1000 300 5 benzene 1011.5g

2,2-dimethylacetic acid, synthetic quartz sand

f 50% 2.33 1200 300 5 bismuth valerate ethyl ester 337.1g

3,3-dimethylacetic acid, synthetic quartz sand

g 5% 46.6 1400 300 5 bismuth valerate ethyl ester 577.8g

Natural quartz sand

h Barium hydroxide water 1% 200 1600 200 2

1000.3g

Natural quartz sand

i 钡钡 hot water 1.5% 150 1800 200 2

1117.5g

Barium hydroxide

And cerium oxide natural quartz sand

j Hot water 1.5% 100 2000 200 2 Mass ratio 1 : 635.2g

Mixture of 1

Natural quartz sand

k Barium hydroxide water 1% 20 400 200 2

400.6g

Barium hydroxide

And barium chloride natural quartz sand

1 water 2% 20 1200 200 2 mass ratio 2: 277.3g

Mixture of 1

Example 1 25Kg of natural quartz sand is placed in a rotating 20-inch crucible mold, and the natural quartz sand is formed into a quartz crucible by centrifugal force, and then a high current is applied to the electrode above the mold, thereby forming an instant of 2000° in the mold. The high-temperature arc of C, slowly melts the quartz sand into a quartz crucible base. After the quartz crucible matrix is melt-formed, adjust the position of the feeding tube, and type 417g of synthetic quartz sand doped with alkaline earth metal crucible 400ppm (predicted thickness b) = 50 (^m, the bottom surface area of the coating is expected to be s = 3500 cm ² , density p = 1.4 g / cm ³ , taking the coefficient K = 1.7), and uniformly introduced into the bottom of the quartz glass crucible base at a rate of 100 g / min. After the surface is finished and melted, after cooling, the crucible is removed, and a quartz glass crucible having a transparent coating (the theoretical thickness of 500 μm) on the inner surface is prepared, and compared with the comparative example, the analysis results are shown in the table. 2. Example 2

25Kg of natural quartz sand is placed in a rotating 20-inch crucible mold, and the natural quartz sand is formed into a quartz crucible by centrifugal force, and then a high current is applied to the electrode above the mold, thereby forming an instant of 2000° in the mold. The arc of C is heated at a high temperature, and the quartz sand is slowly melted into a quartz crucible base. After the quartz crucible base is melt-formed, the position of the feeding tube is adjusted, and the type b is mixed with an alkaline earth metal crucible of 400 ppm of synthetic quartz sand 375 g (predicted thickness) b=45 (^m, the inner surface area of the coated wall is expected to be s=3500 cm ² , density p=1.4 g/cm ³ , taking coefficient K=1.7), and uniformly applied to the wall of the quartz glass crucible base at a speed of 100 g/min. The inner surface of the part, after the end of the material is completed and melted, is cooled and then taken out to obtain a quartz glass crucible with a transparent coating (the theoretical thickness of 450 μηι) on the inner surface, which is compared with the comparative example. Table 2. Example 3

25Kg of natural quartz sand is placed in a rotating 20-inch crucible mold, and the natural quartz sand is formed into a quartz crucible by centrifugal force, and then a high current is applied to the electrode above the mold, thereby forming an instant of 2000° in the mold. The arc of the high temperature state of C slowly melts the quartz sand into a quartz crucible base. After the quartz crucible base is melt-formed, the position of the feeding tube is adjusted, and the type c is doped with an alkaline earth metal crucible of 600 ppm of synthetic quartz sand 666 g to 100 g. The speed of /min is evenly applied to the entire inner surface of the quartz glass crucible base. After the end of the material is completed and the melting is completed, the crucible is removed after cooling to obtain a transparent coating having a crucible inner surface (the theoretical thickness is 400 μm). The glass crucible was compared with the comparative example, and the analysis and evaluation results are shown in Table 2. Example 4

25Kg of natural quartz sand is placed in a rotating 20-inch crucible mold, and the natural quartz sand is formed into a quartz crucible by centrifugal force, and then a high current is applied to the electrode above the mold, thereby forming an instant of 2000° in the mold. The arc of C is heated at a high temperature, and the quartz sand is slowly melted into a quartz crucible base. After the quartz crucible base is melt-formed, the position of the feeding tube is adjusted, and the model d is doped with an alkaline earth metal crucible of 800 ppm of synthetic quartz sand 583 g to 100 g. The speed of /min is evenly applied to the entire inner surface of the quartz glass crucible base. After the end of the material is completed and the melting is completed, the crucible is removed after cooling, and a quartz having a transparent coating (the theoretical thickness of 350 μm) is prepared. The glass crucible was compared with the comparative example, and the analysis and evaluation results are shown in Table 2. Example 5

25Kg of natural quartz sand is placed in a rotating 20-inch crucible mold, and the natural quartz sand is formed into a quartz crucible by centrifugal force, and then a high current is applied to the electrode above the mold, thereby forming an instant of 2000° in the mold. The arc of C is in a high temperature state, and the quartz sand is slowly melted into a quartz crucible base. After the quartz crucible base is melt-formed, the position of the feeding tube is adjusted, and the type e is doped with an alkaline earth metal 钡100 ppm of synthetic quartz sand 500g to 100g. The speed of /min is evenly applied to the entire inner surface of the quartz glass crucible base. After the end of the material is completed and the melting is completed, the crucible is removed after cooling to obtain a transparent coating (the theoretical thickness of 300 μηι) of the inner surface is doped with antimony. The glass crucible was compared with the comparative example, and the analysis and evaluation results are shown in Table 2. Example 6

25Kg of natural quartz sand is placed in a rotating 20-inch crucible mold, and the natural quartz sand is formed into a quartz crucible by centrifugal force, and then a high current is applied to the electrode above the mold, thereby forming an instant of 2000° in the mold. The arc of the high temperature state of C slowly melts the quartz sand into a quartz crucible base. After the quartz crucible matrix is melt-formed, the position of the feeding tube is adjusted, and 208 g of synthetic quartz sand doped with alkaline earth metal crucible 1200 ppm of model f is 100 g. The speed of /min is evenly applied to the inner surface of the wall of the quartz glass crucible base. After the end of the material is completed and the melting is completed, the crucible is removed after cooling to obtain a transparent coating with a crucible inner surface (the theoretical thickness is 250 μm). The glass crucible was compared with the comparative example, and the analysis and evaluation results are shown in Table 2. Example 7

25Kg of natural quartz sand is placed in a rotating 20-inch crucible mold, and the natural quartz sand is formed into a quartz crucible by centrifugal force, and then a high current is applied to the electrode above the mold, thereby forming an instant of 2000° in the mold. The arc of the high temperature state of C slowly melts the quartz sand into a quartz crucible base. After the quartz crucible base is melt-molded, the position of the feeding tube is adjusted, and 167 g of synthetic quartz sand doped with an alkaline earth metal crucible of 1400 ppm is introduced in a type g of 100 g. The speed of /min is evenly applied to the inner surface of the bottom of the quartz glass crucible base. After the end of the material is completed and the melting is completed, the crucible is removed after cooling to obtain a transparent coating having a crucible inner surface (the theoretical thickness is 200 μm). The glass crucible was compared with the comparative example, and the analysis and evaluation results are shown in Table 2. Example 8

25Kg of natural quartz sand is placed in a rotating 20-inch crucible mold, and the natural quartz sand is formed into a quartz crucible by centrifugal force, and then a high current is applied to the electrode above the mold, thereby forming an instant of 2000° in the mold. The arc of C is in a high temperature state, and the quartz sand is slowly melted into a quartz crucible base. After the quartz crucible base is melt-molded, the position of the feeding tube is adjusted, and 125 g of synthetic quartz sand doped with an alkaline earth metal crucible of 1600 ppm is introduced in a model h of 100 g. The speed of /min is evenly applied to the inner surface of the wall of the quartz glass crucible base. After the end of the material is completed and the melting is completed, the crucible is removed after cooling to obtain a transparent coating having a crucible inner surface (the theoretical thickness is 150 μm). The glass crucible was compared with the comparative example, and the analysis and evaluation results are shown in Table 2. Example 9

25Kg of natural quartz sand is placed in a rotating 20-inch crucible mold, and the natural quartz sand is formed into a quartz crucible by centrifugal force, and then a high current is applied to the electrode above the mold, thereby forming an instant of 2000° in the mold. The arc of the high temperature state of C slowly melts the quartz sand into a quartz crucible base. After the quartz crucible matrix is melt-formed, the position of the feeding tube is adjusted, and the type i is doped with alkaline earth metal 钡1800 ppm of natural quartz sand and synthetic quartz sand. 167 g of mixed sand was uniformly introduced into the entire inner surface of the quartz glass crucible base at a rate of 100 g/min. After the completion of the charging and melting, the crucible was removed after cooling to obtain a transparent coating having an inner surface doped with antimony ( The quartz glass crucible having a theoretical thickness of ΙΟΟμηι) was compared with the comparative example, and the analysis and evaluation results are shown in Table 2. Example 10

25Kg of natural quartz sand is placed in a rotating 20-inch crucible mold, and the natural quartz sand is formed into a quartz crucible by centrifugal force, and then a high current is applied to the electrode above the mold, thereby forming an instant of 2000° in the mold. The arc of the high temperature state of C slowly melts the quartz sand into a quartz crucible base. After the quartz crucible base is melt-molded, the position of the feeding tube is adjusted, and the mixed sand of the synthetic quartz sand doped with alkaline earth metal 钡 2000 ppm is mixed with the model j. , uniformly applied to the entire inner surface of the quartz glass crucible base at a rate of 100 g/min. After the completion of the feeding and melting, the crucible is removed after cooling to obtain a transparent coating having a crucible inner surface (theoretical thickness is 50 μm). The quartz glass crucible is compared with the comparative example, and the evaluation results are shown in Table 2. Example 11

25Kg of natural quartz sand is placed in a rotating 20-inch crucible mold, and the natural quartz sand is formed into a quartz crucible by centrifugal force, and then a high current is applied to the electrode above the mold, thereby forming an instant of 2000° in the mold. The arc in the high temperature state of C slowly melts the quartz sand into a quartz crucible base. After the quartz crucible matrix is melt-formed, the position of the feeding tube is adjusted, and the type k is doped with an alkaline earth metal crucible of 400 ppm of synthetic quartz sand 334 g to 100 g. The speed of /min is evenly applied to the entire inner surface of the quartz glass crucible base. After the end of the material is completed and the melting is completed, the crucible is removed after cooling to obtain a transparent coating having a crucible inner surface (the theoretical thickness is 200 μm). The glass crucible was compared with Comparative Example 4, and the analysis and evaluation results are shown in Table 2. Example 12

25Kg of natural quartz sand is placed in a rotating 20-inch crucible mold, and the natural quartz sand is formed into a quartz crucible by centrifugal force, and then a high current is applied to the electrode above the mold, thereby forming an instant of 2000° in the mold. The arc of C is heated at a high temperature, and the quartz sand is slowly melted into a quartz crucible base. After the quartz crucible base is melt-formed, the position of the feeding tube is adjusted, and the type 1 is doped with an alkaline earth metal crucible of 1200 ppm of natural quartz sand 167 g to 100 g. The speed of /min is evenly applied to the entire inner surface of the quartz glass crucible base. After the end of the material is completed and the melting is completed, the crucible is removed after cooling to obtain a transparent coating having a crucible inner surface (the theoretical thickness is ΙΟΟμηι). The glass crucible was compared with the comparative example, and the analysis and evaluation results are shown in Table 2. Comparative Example 1:

25Kg of natural quartz sand is placed in a rotating 20-inch crucible mold, and the natural quartz sand is formed into a quartz crucible by centrifugal force, and then a high current is applied to the electrode above the mold, thereby forming an instant of 2000° in the mold. The arc of the high temperature state of C slowly melts the quartz sand into a quartz crucible, and after cooling, it is taken out to obtain a normal quartz crucible without surface treatment. Comparative Example 2:

25 Kg of natural quartz sand was placed in a rotating 20 inch crucible mold, and the natural quartz sand was formed into a quartz crucible by centrifugal force. Then, a high current is applied to the electrode above the mold, and an arc of a high temperature state of >2000 ° C is instantaneously formed in the mold, and the quartz sand is slowly melted into a quartz crucible base, and the quartz crucible base is melt-molded, and then taken out after cooling to obtain An ordinary quartz crucible substrate without surface treatment, and then uniformly spraying 100 g of a 1.5% lithium hydroxide solution on the entire inner surface of the quartz crucible substrate, and drying at 200 ° C for 2 hours, and the inner surface is coated with Awkward quartz glass crucible. Comparative Example 3:

25 Kg of natural quartz sand was placed in a rotating 20 inch crucible mold, and the natural quartz sand was formed into a quartz crucible by centrifugal force. Then, a high current is applied to the electrode above the mold, and an arc of a high temperature state of >2000 ° C is instantaneously formed in the mold, which is slow. The quartz sand is melted into a quartz crucible base, and the quartz crucible base is melt-molded, and after cooling, it is taken out to obtain a common quartz crucible base without surface treatment, and then uniformly sprayed on the inner surface of the bottom surface of the quartz crucible base to have a concentration of 100 g of 1.5%. A solution of cerium isovalerate in toluene was dried at 800 ° C for 3 hours to prepare a quartz glass crucible having an inner surface coated with ruthenium. Comparative example 4

25Kg of natural quartz sand is placed in a rotating 20-inch crucible mold, and the natural quartz sand is formed into a quartz crucible by centrifugal force, and then a high current is applied to the electrode above the mold, thereby forming an instant of 2000° in the mold. The arc in the high temperature state of C slowly melts the quartz sand into a quartz crucible base. After the quartz crucible matrix is melt-formed, the position of the feeding tube is adjusted, and 334 g of synthetic quartz sand doped with an alkaline earth metal crucible of 150 ppm is applied at 100 g/min. The speed was evenly applied to the entire inner surface of the quartz glass crucible base. After the completion of the charging and the completion of the melting, the crucible was removed after cooling, and a quartz glass crucible having a transparent coating (the theoretical thickness of 200 μηι) having a crucible on the inner surface was obtained. In order to characterize the comparative properties of the quartz crucible of the present invention and the inner surface coated with a ruthenium-containing coating, the characterization methods were respectively: (1) The inner surface of the crucible was rinsed with high pressure water at a pressure of 0.2 MPa for 25 minutes, before and after the rinsing. The amount of metal oxide remaining on the surface area per unit surface; (2) After soaking for 5 minutes in HF acid at a concentration of 10%, the inner surface of the crucible is washed with pure water, and the surface area per unit surface of the crucible is compared before and after the acid washing. The amount of metal oxide; (3) The enthalpy is subjected to a single crystal test, and the dislocation-free ratio of the single crystal silicon drawn by several enamels is compared (the calculation of the dislocation-free ratio is the quality of the dislocation-free single crystal). The amount accounts for the mass ratio of the polysilicon loaded in the crucible). The test results are shown in Table 2 below. Table 2

Claims

Claim

A quartz glass crucible comprising a crucible base, characterized in that the inner surface of the crucible base of the quartz glass crucible is coated with a transparent coating having a theoretical thickness of 50 to 500 μm, the transparent coating The layer is prepared by melt-doping quartz sand doped with an alkaline earth metal element, which is natural quartz sand, synthetic quartz sand or a mixture of the two in any ratio, and the alkaline earth metal element refers to magnesium element, strontium element, a cerium element or a calcium element derived from a mixture of cerium oxide, an alkali earth metal base, an alkaline earth metal salt or an alkaline earth metal base and an alkaline earth metal salt in an arbitrary ratio, the alkaline earth metal element-doped quartz The mass content of the alkaline earth metal element in the sand is 400 to 2000 ppm, and the inner surface refers to the inner surface of the bottom of the base of the base, the inner surface of the wall of the base of the base or the entire inner surface of the base of the base.

2. The quartz glass crucible according to claim 1, wherein the transparent coating layer is obtained by preparing a quartz glass crucible base body by using a crucible mold, and after the base material is melt-molded, and then connected to the crucible mold. The electrode is energized with a strong current, and an arc of a high temperature state is instantaneously formed in the mold, and then quartz sand doped with an alkaline earth metal element is uniformly introduced, and is melted at a high temperature and then coated on the inner surface of the quartz glass crucible base body to obtain The clear coating.

The quartz glass crucible according to claim 2, wherein the crucible base is obtained by melting natural quartz sand.

A quartz glass crucible according to claim 1, wherein said transparent coating has a theoretical thickness of 50 to 100 μm.

5. The quartz glass crucible of claim 1 which is doped with an alkaline earth metal The mass content of the alkaline earth metal element in the quartz sand of the element is 800 to 1200 ppm.

The quartz glass crucible according to claim 1, wherein the alkali earth metal base is one or a mixture of two or more of the following: magnesium hydroxide, barium hydroxide, barium hydroxide or calcium hydroxide; The alkaline earth metal salt is an alkaline earth metal inorganic salt and/or an alkaline earth metal organic salt, and the alkaline earth metal inorganic salt is one or a mixture of two or more of the following: MeX _n , n is 1 or 2, wherein Me is Mg ²⁺ , Ba ²⁺ , Sr ²⁺ or Ca ²⁺ , X is F -, Cl\ COO\ CH ₃ COO\ C ₂ H ₅ COO\ C0 ₃ ² \ Si0 ₃ ^2- or C ₂ 0 ₄ ^2- ; When X is F -, Cl\ COO\ CH ₃ COO\ C ₂ H ₅ COO-, n=2; when X is C0 ₃ ^2- , Si0 ₃ ^2- or C ₂ 0 ₄ ^2- , n=l; The alkaline earth metal organic salt is one or a mixture of two or more of the following: (R) ₂ M, wherein M is Mg, Ba, Sr or Ca, R is C _m H _2m+1 COO, m=3~8 The integer.

The quartz glass crucible according to claim 5, wherein the quartz sand doped with an alkaline earth metal element is obtained by the following method: cerium oxide, alkali earth metal alkali, alkaline earth metal salt or alkaline earth metal a mixture of an alkali and an alkaline earth metal salt in an arbitrary ratio is formulated into a solution having a mass percentage of 0.01 to 50%, and added to quartz sand, which is natural quartz sand, synthetic quartz sand or a mixture of the two in any ratio. Mix well and then dry at 50~1000 °C for 1~10 hours to obtain quartz sand doped with alkaline earth metal elements, so that the content of alkaline earth metal elements in quartz sand is 400~2000ppm.

The quartz glass crucible according to claim 1, wherein the quartz glass crucible is obtained by the following method:

(1) preparing a mixture of cerium oxide, an alkali earth metal base, an alkaline earth metal salt or an alkaline earth metal base and an alkaline earth metal salt in an arbitrary ratio of 0.01 to 50% by mass, and adding it to quartz sand. The quartz sand is natural quartz sand, synthetic quartz sand or The mixture of the two is mixed in an arbitrary ratio, and then thoroughly stirred and mixed, and then dried at 50 to 1000 ° C for 1-10 hours to obtain a quartz sand doped with an alkaline earth metal element, and the mass percentage of the alkaline earth metal element in the quartz sand is obtained. 400~2000ppm; the alkali earth metal base is one or a mixture of two or more of the following: magnesium hydroxide, barium hydroxide, barium hydroxide or calcium hydroxide; the alkaline earth metal salt is an alkaline earth metal inorganic salt and / Or an alkaline earth metal organic salt, the alkaline earth metal inorganic salt being one or a mixture of two or more of the following: MeX _n , n is 1 or 2, wherein Me is Mg ²⁺ , Ba ²⁺ , Sr ²⁺ or Ca ²⁺ , X is F -, Cl\ COO\ CH ₃ COO\ C ₂ H ₅ COO\ C0 ₃ ² \ Si0 ₃ ^2- or C ₂ 0 ₄ ^2- ; X is F -, Cl\ COO\ CH ₃ COO \ C ₂ H ₅ COO-, n=2; when X is C0 ₃ ^2- , Si0 ₃ ^2- or C ₂ 0 ₄ ^2- , n=l; the alkaline earth metal organic salt is one of the following or Mixing two or more: (R) ₂ M, where M is Mg, Ba, Sr or Ca, R is C _m H _2m+1 COO, m = an integer of 3-8;

(2) The natural quartz sand is placed in a rotating boring mold, and the natural quartz sand is formed into a braid shape under the action of centrifugal force, and then a high current is applied to the electrode above the enamel mold to form an arc at a high temperature of 2000 ° C or higher, which is slow. The natural quartz sand is melted and formed into a ruthenium matrix. After the ruthenium matrix is melt-formed, the alkaline earth metal-doped quartz sand obtained in the step (1) is uniformly introduced into the ruthenium matrix at a rate of 50 to 100 g/min. a surface, the inner surface is a bottom inner surface of the base of the crucible, an inner surface of the wall of the crucible base, or the entire inner surface of the crucible base. After the feeding is completed and the melting is completed, the quartz glass crucible is obtained after being cooled and taken out; The mass amount m of the quartz sand doped with the alkaline earth metal element is calculated by estimating the thickness b of the transparent coating layer and the area S of the inner surface to be coated, according to the formula m=KxSxbxp, where K is a different size diameter 坩埚 empirical coefficient, K=1.2~1.8, ρ is the density of quartz sand doped with alkaline earth metal elements, the expected penetration The thickness b of the bright coating layer is 50 to 500 μm.

The quartz glass crucible according to claim 8, wherein the alkali earth metal base is barium hydroxide; the alkaline earth metal inorganic salt is barium carbonate or barium silicate, and the alkaline earth metal organic salt is stearic acid. Sour or octoate.

The quartz glass crucible according to claim 9, wherein the alkaline earth metal element has a mass percentage of 800 to 1200 ppm in the quartz sand, and the expected transparent coating has a thickness b of 50 to 100 μη.