Rim-coated synthetic crucible

Abstract

A synthetic quartz crucible for holding a silicon melt during the growth of a single crystal silicon ingot is disclosed. The crucible may include a coating disposed on the interior surface along the rim and other surfaces of the crucible body. The coating may extend only partially along the sidewall of the crucible and may extend up to or beyond the melt line of the crucible.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Non-Provisional Patent Application No. 17 / 897,677, filed August 29, 2022, the entire text of which is incorporated herein by reference. [Technical Field]

[0002] The field of the disclosure relates to crucibles for growing single crystal silicon ingots by the Czochralski method, and in particular to composite crucibles that include a rim coating. [Background technology]

[0003] Quartz crucibles are traditionally used to hold the silicon melt during the Czochralski single crystal silicon growth process. During ingot growth, the crucible softens and may deform. This deformation can cause the crucible to come into contact with hot zone components, including the heat shield, resulting in the loss of a dislocation-free ingot.

[0004] Synthetic quartz is sometimes used as a crucible liner to reduce impurities introduced into the melt during ingot growth. Synthetic quartz crucibles are characterized by increased melt vibration, which can lead to more neck popping and increased retry times.

[0005] There is a need for a synthetic quartz crucible that resists deformation, improves crucible smoothness, and increases the success rate of zero dislocations.

[0006] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the disclosure described and / or claimed below. This discussion is believed to be helpful in providing the reader with background information to better understand the various aspects of the present disclosure. As such, it should be understood that these statements are to be read in this light, and not as admissions of prior art. SUMMARY

[0007] One aspect of the present disclosure relates to a crucible for holding a silicon melt. The crucible includes a body having a bottom and a sidewall extending upward from the bottom. The bottom and sidewall define a cavity for holding the silicon melt. The sidewall has a top surface, an inner surface, and an outer surface. The height of the sidewall extends from the bottom to the top of the sidewall. The body is made of synthetic quartz. A coating is disposed on a first inner surface region of the inner surface of the sidewall. The coating includes magnesium, calcium, strontium, and barium. The first inner surface region extends from the top of the sidewall only a distance D1 from the top of the sidewall. Distance D1 is less than the height of the sidewall.

[0008] Another aspect of the present disclosure relates to a method for manufacturing a crucible. A body is provided having a bottom and a sidewall extending upward from the bottom. The bottom and sidewall define a cavity for holding a silicon melt. The sidewall has a top surface, an inner surface, and an outer surface. The height of the sidewall extends from the bottom to the top of the sidewall. The body is made of synthetic quartz. A coating is applied to a first inner surface region of the inner surface of the sidewall. The coating includes magnesium, calcium, strontium, and barium. The first inner surface region extends from the top of the sidewall only a distance D1 from the top of the sidewall. Distance D1 is less than the height of the sidewall.

[0009] Yet another aspect of the present disclosure relates to a method for forming a monocrystalline silicon ingot. An initial charge of polycrystalline silicon is added to a crucible. The crucible includes a body having a bottom and a sidewall extending upward from the bottom. The bottom and sidewall define a cavity for holding a silicon melt. The sidewall has a top, an inner surface, and an outer surface. The height of the sidewall extends from the bottom to the top of the sidewall. The body is made of synthetic quartz. A coating is disposed on a first inner surface region of the inner surface of the sidewall. The coating includes magnesium, calcium, strontium, and barium. The first inner surface region extends only from the top of the sidewall to a distance D1 from the top of the sidewall. The distance D1 is less than the height of the sidewall. The initial charge of polycrystalline silicon is heated to form a silicon melt in the crucible. A silicon seed crystal is brought into contact with the silicon melt. The silicon seed crystal is withdrawn to grow a monocrystalline silicon ingot.

[0010] Various refinements exist in the features described in connection with the above aspects of the present disclosure. Additional features may also be incorporated into the above aspects of the present disclosure. These refinements and additional functionality may exist individually or in any combination. For example, various features described below in connection with any of the illustrated embodiments of the present disclosure may be incorporated alone or in any combination into any of the above aspects of the present disclosure. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view of an ingot pulling apparatus before silicon ingot growth. [Figure 2] FIG. 2 is a cross-sectional view of the ingot pulling apparatus of FIG. 1 during silicon ingot growth. [Figure 3] 3 is a perspective view of a crucible body of the crucible of the ingot pulling apparatus of FIG. 1. FIG. [Figure 4] FIG. 4 is a perspective view of the crucible body showing the melt line and rim coating distances D1 and D2. [Figure 5] FIG. 5 is a perspective view of another embodiment of a crucible body showing the melt line and rim coating distances D1 and D2. [Figure 6] FIG. 6 is a cross-sectional view of the crucible of the ingot pulling apparatus of FIG. [Figure 7] FIG. 7 is a cross-sectional view of another embodiment of a crucible. [Figure 8] FIG. 8 includes a graph showing the number of neck trials and popouts for crucibles with rim coatings that do not extend to the melt line and crucibles with rim coatings that extend to the melt line. [Figure 9] Figure 9 contains a bar graph showing the frequency with which the zero dislocation state is lost in the crown / initial body of crucibles with a rim coating that does not extend to the melt line and crucibles with a rim coating that does extend to the melt line. [Figure 10] Figure 10 includes a bar graph showing the normalized total body ratio versus trial number for crucibles with a rim coating that did not extend to the melt line and crucibles with a rim coating that did extend to the melt line.

[0012] Corresponding reference characters indicate corresponding parts throughout the drawings.

[0013] 1, provisions of the present disclosure relate to a coated crucible 102 (e.g., a rim-coated crucible) for holding a silicon melt within an ingot pulling apparatus 100. The ingot pulling apparatus 100 and its crucible 102 are suitable for growing a single crystal silicon ingot 113 (FIG. 2) by the Czochralski method.

[0014] Crucible 102 includes a crucible body 103 (FIG. 3) on which one or more coatings are applied, as further described below. Crucible body 103 has a bottom 101 and a sidewall 114 extending from bottom 101. Bottom 101 and sidewall 114 define a cavity 144 for holding a silicon melt.

[0015] The sidewall 114 is generally vertical and cylindrical in shape. The sidewall 114 of the crucible body 103 has an inner surface 112 and an outer surface 120. The sidewall 114 has a top 115 and a height H114 that extends from the bottom 101 to the top 115. The bottom 101 of the crucible body includes a curved portion 147 of the crucible body 103 that extends below the sidewall 131. The portion of the crucible body 103 adjacent the top 115 of the sidewall 114 is sometimes referred to herein as the "rim" of the crucible.

[0016] The crucible body 103 can be constructed of any material suitable for holding a silicon melt. For example, the crucible body 103 may be made from quartz. In some embodiments, the crucible body may include synthetic quartz. For example, the crucible body 103 may include a synthetic quartz liner such that the inner surface 112 of the crucible body 103, which contacts the melt, is synthetic quartz. Synthetic quartz may be made by a synthetic process, such as hydrothermally produced quartz. To form a synthetic quartz crucible, natural sand is arc-welded to form the crucible body shell, and synthetic sand is arc-welded to the inner surface of the shell as a liner. The synthetic sand liner may have relatively low impurity levels (e.g., 5-10 times lower) compared to the natural sand shell. For example, natural sand may have impurity concentrations of at least 5 ppm aluminum, at least 0.1 ppm calcium, at least 0.1 ppm iron, at least 0.1 ppm potassium, at least 0.05 ppm lithium, at least 0.3 ppm sodium, and at least 0.5 ppm titanium, while synthetic sand may have impurity concentrations of less than 0.01 ppm aluminum, less than 0.01 ppm calcium, less than 0.075 ppm iron, less than 0.01 ppm potassium, less than 0.01 ppm lithium, less than 0.01 ppm potassium, and less than 0.01 ppm titanium. The crucible body 103 (including its liner) may have any thickness that enables the crucible to function as described herein.

[0017] At least a portion of the inner surface 112 and outer surface 120 of the sidewall 114 of the crucible body 103 described above may be coated with a coating composition. The coating composition may include an oxide or carbonate of magnesium, calcium, strontium, or barium (e.g., a hydroxide thereof, such as BA(OH)). In some embodiments, the coating composition includes a barium hydroxide or carbonate, such as BA(OH) or BACO.

[0018] The oxide may be dissolved or suspended in a solution or carrier, such as deionized water. The coating composition may be applied to the first interior surface region 121 of the interior surface 112 of the body 103 and the first exterior surface region 123 of the exterior surface 120 of the body 103. The hydroxide or carbonate may be dissolved or suspended in a solution or carrier, such as deionized water or a mixture of water and isopropyl alcohol. The coating composition may be applied to the first interior surface region 121 of the interior surface 112 of the body 103 and the first exterior surface region 123 of the exterior surface 120 of the body 103.

[0019] The first interior surface region 121 to which the coating is applied extends only from the top 115 of the sidewall 114 to a distance D1 from the top of the sidewall. This distance D1 is equal to the height H of the sidewall 114. 114 The first exterior surface region 123 extends only from the top 115 of the side wall 114 to a distance D2 from the top of the side wall 114. This distance D2 is less than the height H114 of the side wall 114. D1 and D2 may be the same distance as shown in FIGS. 3-5, or may be different distances as in other embodiments.

[0020] In some embodiments, D1 (and optionally D2) corresponds to the location of the melt line ML ( FIG. 1 ). The melt line ML is the location on the inner sidewall surface 112 where the surface 111 of the melt 104 meets the crucible 102 during the “stabilization phase” of the ingot growth process. That is, the coating extends to the melt line ML. As shown in FIG. 4 , the melt line ML has a width W (i.e., the melt line is a band formed on the inner surface of the crucible), which is the width the crucible erodes at the interface during the stabilization phase. This width results from the different centrifugal forces applied to the melt at different crucible rotation speeds during stabilization, neck growth, and crown growth. This width can be at least 1 mm, at least 5 mm, or at least 10 mm (e.g., 1 mm to 20 mm, or 5 mm to 15 mm). The coating may be above the melt line ML, below the melt line ML, to a point between the top and bottom of the melt line ML, or extend below the melt line ML as described below (FIG. 5).

[0021] 5, the distance D1 that the coating extends from the top 115 of the crucible (and optionally the distance D2 that the coating extends across the first exterior surface region 123) is below the meltline ML. For example, the length that distance D1 extends below the meltline (i.e., below the bottom of the meltline ML) may be at least 1 time the width of the meltline ML, or at least 5 times the width of the meltline ML, or between 1 and 10 times the width of the meltline ML, or between 1 and 5 times the width of the meltline ML. This length that the coating extends below the meltline ML may be at least 5 mm, at least 10 mm, at least 25 mm, at least 50 mm, at least 100 mm, or between 5 mm and 100 mm, between 10 mm and 100 mm, or between 10 mm and 25 mm below the meltline ML.

[0022] The inner surface 112 of the crucible body 103 may include a second inner surface region 125 extending from D1 to the bottom 101 of the crucible body 103. In some embodiments, the second inner surface region 125 (and optionally 101) has no coating disposed thereon (i.e., no coating other than the synthetic quartz liner of the crucible body 103). In other embodiments (e.g., natural sand crucibles), at least a portion of the second inner surface region 125 (and optionally 101) has a coating disposed thereon that is different from the coatings described above.

[0023] The coating composition may be applied to the first interior surface region 121 and the first exterior surface region 123 by dipping the crucible into the coating composition. In other embodiments, the coating is applied by chemical vapor deposition, plasma spraying, brushing, aerosol spraying, pouring, or any combination thereof. The coating composition may be applied in a single application or multiple applications until the desired thickness is reached. The final coating thickness will be at least about 1 μm.

[0024] Once the coating composition has been applied to the first interior surface region 121 and the first exterior surface region 123, the composition can be dried to evaporate the carrier (e.g., water). Generally, the crucible can be dried under any atmosphere, including, for example, ambient air, nitrogen, argon, or a mixture thereof. Generally, when ambient air is utilized, a significant portion, if not all, of the carrier evaporates after about 20 minutes, and in other embodiments, after about 30 or 40 minutes. Increasing ventilation (e.g., circulating air) can proportionally reduce drying time. Generally, a coating is dry when it does not stick to or transfer material to a person's finger when it comes into contact with the finger.

[0025] The coating composition can be applied and dried multiple times to increase the coating thickness. Each layer may be allowed to air dry to remove the carrier before applying the next layer. Alternatively or additionally, heating can be used. In some embodiments, the crucible is heated to at least about 150°C, at least about 200°C, at least about 300°C, at least about 400°C, or at least about 750°C to dry and sinter the coating composition. The crucible is heated for at least about 1 hour, and in other embodiments, for at least about 2 hours, at least about 3 hours, or from about 1 hour to about 5 hours.

[0026] The crucible may be heated in the presence of an inert gas, such as nitrogen, helium, or argon. Ambient air can be used as the atmosphere during heating, but this is less preferred due to the potential for oxygen contamination of the coating. Additionally, as will be appreciated by those skilled in the art, the furnace materials of construction and gas flow can be controlled to avoid oxidation of the coating.

[0027] In some embodiments, a second coating is disposed on one or more portions of the inner surface 112 and the outer surface 120 prior to application of the above-described coating (sometimes referred to herein as the "first" coating). For example, a second coating 133 (FIG. 6) can be disposed on at least a portion of the outer surface of the crucible. The second coating 133 can be disposed on a second outer surface region 127 of the outer surface 120 of the sidewall 114. The second outer surface region 127 extends from the first outer surface region 123 (FIG. 3) to the bottom 101 of the crucible body 103. The second coating 133 can also be disposed on the first outer surface region 123 (i.e., between the crucible body 103 and the first coating 109). The second coating 133 is different from the first coating 109. For example, the second coating 133 can include aluminum. In some embodiments, the aluminum-containing second coating 133 is not applied above the melt line ML.

[0028] 7, in other embodiments, the crucible 102 does not include a second coating on the outer surface 120 of the side wall (or the inner surface 112 of the side wall). The coating 109 described above is applied directly to the outer surface 120 and / or the inner surface 112.

[0029] The coated crucible 102 described above can be used to produce a single crystal silicon ingot by the Czochralski process. The crucible can generally be used in any ingot puller adapted to pull a single crystal silicon ingot. An example of an ingot puller (or more simply, an "ingot puller") is generally designated "100" in FIG. 1. The ingot puller 100 includes the crucible 102 described above for holding a silicon melt 104. The crucible 102 is supported by a susceptor 106. The ingot puller 100 includes a crystal pulling housing 108 defining a growth chamber 152 in which a silicon ingot 113 (FIG. 2) is pulled from the melt 104 along a pulling axis A.

[0030] Crucible 102 has a bottom 129 and a sidewall 117 extending from the bottom or bottom 129. Sidewall 117 is generally vertical and cylindrical in shape. Bottom 129 of crucible 102 includes a curved portion of crucible 102 that extends below sidewall 131. Crucible 102 is supported by susceptor 106. Susceptor 106 is supported by shaft 105. Susceptor 106, crucible 102, shaft 105, and ingot 113 (FIG. 2) share a common longitudinal axis A, or "pull axis," A.

[0031] The ingot pulling apparatus 100 includes a pulling mechanism 132 for growing and pulling an ingot 113 from the melt 104. The pulling mechanism 132 includes a pulling cable 118, a seed holder or chuck 155 coupled to one end of the pulling cable 118, and a silicon seed crystal 122 coupled to the seed holder or chuck 155 for initiating crystal growth. One end of the pulling cable 118 is connected to a pulley (not shown) or drum (not shown) or other suitable type of lifting mechanism, such as a shaft, and the other end is connected to the chuck 155, which holds the seed crystal 122. During operation, the seed crystal 122 is lowered into contact with the melt 104. The pulling mechanism 132 is actuated to raise the seed crystal 122, thereby pulling a single crystal ingot 113 ( FIG. 2 ) from the melt 104.

[0032] During heating and crystal pulling, a crucible drive unit 107 (e.g., a motor) rotates the crucible 102 and susceptor 106. A lift mechanism 132 raises and lowers the crucible 102 along the pull axis A during the growth process. For example, as shown in FIG. 1, the crucible 102 may be in its lowest position (near the bottom heater 126) where an initial charge of solid-phase polycrystalline silicon pre-added to the crucible 102 is melted. Crystal growth is initiated by contacting the melt 104 with the seed crystal 122 and lifting the seed crystal 122 with the pulling mechanism 132. As the ingot grows, the silicon melt 104 is consumed and the melt height within the crucible 102 decreases. The crucible 102 and susceptor 106 can be raised to keep the melt surface 111 at or near the same position relative to the ingot pulling apparatus 100 (FIG. 2).

[0033] The crystal drive unit (not shown) can also rotate the pulling cable 118 and ingot 113 ( FIG. 2 ) in a direction opposite (e.g., counter-rotation) from the direction in which the crucible drive unit 107 rotates the crucible 102. In embodiments using equal rotation, the crystal drive unit can rotate the pulling cable 118 in the same direction as the crucible drive unit 107 rotates the crucible 102. Additionally, the crystal drive unit raises and lowers the ingot 113 relative to the melt surface 111 as needed during the growth process.

[0034] The ingot pulling apparatus 100 may include an inert gas system for introducing and evacuating an inert gas, such as argon, to and from the growth chamber 152. The ingot pulling apparatus 100 may also include a dopant delivery system (not shown) for introducing dopants into the melt 104.

[0035] According to the Czochralski single crystal growth process, a crucible 102 is filled with a certain amount of polycrystalline silicon, or polysilicon. The initial semiconductor- or solar-grade material introduced into the crucible is melted by heat provided by one or more heating elements to form a silicon melt within the crucible. The ingot puller 100 includes bottom insulation 110 and side insulation 124 to retain heat within the puller. In the illustrated embodiment, the ingot puller 100 includes a bottom heater 126 positioned below the crucible bottom 129. The crucible 102 may be moved relatively close to the bottom heater 126 to melt the polycrystalline silicon loaded into the crucible 102.

[0036] Before the ingot is grown, the melt 104 may be cooled and stabilized in a stabilization stage. During the stabilization stage (and subsequent neck and crown growth), erosion at the interface between the surface 111 of the melt 104 and the crucible 102 forms a melt line ML within the crucible.

[0037] To form an ingot after the stabilization phase, a seed crystal 122 is contacted with the surface 111 of the melt 104. A pulling mechanism 132 operates to pull the seed crystal 122 from the melt 104. Referring to FIG. 2 , the ingot 113 includes a crown portion 142 where the ingot transitions outward from the seed crystal 122 and tapers to a target diameter. The ingot 113 includes a constant diameter portion 145 or cylindrical "body" of the crystal grown by increasing the pulling rate. The body 145 of the ingot 113 has a relatively constant diameter. The ingot 113 includes a tail or end cone (not shown) where the diameter of the ingot narrows after the body 145. Once the diameter is sufficiently small, the ingot 113 is separated from the melt 104. Once the ingot 113 is grown, it is sliced ​​into multiple silicon substrates (i.e., wafers).

[0038] The ingot pulling apparatus 100 includes a side heater 135 and a susceptor 106 that surrounds the crucible 102 to maintain the temperature of the melt 104 during crystal growth. The side heater 135 is positioned radially outward of the crucible sidewall 131 as the crucible 102 moves up and down along the pulling axis A. The side heater 135 and the bottom heater 126 may be any type of heater that enables the side heater 135 and the bottom heater 126 to operate as described herein. In some embodiments, the heaters 135, 126 are resistance heaters. The side heater 135 and the bottom heater 126 are controlled by a control system (not shown) to control the temperature of the melt 104 throughout the pulling process.

[0039] The ingot pulling apparatus 100 may include a heat shield 151. The heat shield 151 covers the ingot 113 and may be positioned within the crucible 102 during crystal growth (FIG. 2).

[0040] The ingot growth process may be a batch process in which no polycrystalline silicon is added to the crucible 102 during ingot growth. In other embodiments, a continuous Czochralski process is used, in which polycrystalline silicon is added to the crucible 102 during ingot growth (e.g., the crucible has one or more fluid barriers that divide the crucible into various zones). In some embodiments, a devitrification promoter, such as a barium source, is added to the polycrystalline silicon charge or silicon melt to modify the properties of the crucible below the melt line ML during ingot growth. The devitrification promoter modifies the region below the melt line, while the coating adds rigidity to the crucible base above the melt line. The growth process may use magnetic Czochralski growth (e.g., HMCZ) or non-magnetic Czochralski growth. In some embodiments, no magnetic field is applied during ingot growth.

[0041] The high temperature ingot growth process can alter the coating. For example, in embodiments where barium is used, the barium in the barium oxide coating can react with the quartz crucible material, causing the barium to dissolve into the quartz crucible body 103.

[0042] Compared to conventional crucible and ingot growth processes, the crucible and ingot growth process of the present invention offer several advantages. Coating the top of the crucible, above the melt line, increases the rigidity of the upper portion of the crucible and reduces deformation. A deformed crucible may contact the heat shield and result in a loss of zero dislocations (ZD) within the crucible. Not coating the area below the coated surface reduces air pockets. The coating may extend below the melt line (e.g., between 1 and 10 times the width of the melt line), reducing vibrations caused by the wavy surface just below the melt line, which is more pronounced in synthetic quartz crucibles. The coating maintains the smoothness of the crucible even over extended runs. The extended rim coating provides more stable neck control and eliminates dislocations in the neck. This results in improved zero dislocation achievement in the crown and body growth stages, and improved zero dislocation achievement throughout the body. The enhanced coating reduces the number of necking operations and improves the refillability of the crucible. The enhanced coating reduces melt vibration during neck growth, reducing neck popping in both magnetic and non-magnetic Czochralski processes. The coating reduces crucible melting at the melt line and quartz crucible particle breakage into the melt, improving the success rate of zero dislocations. [Example]

[0043] The processes of the present disclosure are further illustrated by the following examples, which should not be construed in a limiting sense. Example 1: Crucible without barium coating up to the melt line compared to a crucible with barium coating up to the melt line

[0044] Synthetic quartz crucibles were used to grow three monocrystalline silicon ingots: the parent ingot (R0), the ingot grown after a refill of polycrystalline silicon (R1), and the ingot grown after a second refill of polycrystalline silicon (R2). For each ingot run, the number of necking attempts (i.e., the number of necking attempts) and the number of pop-out events relative to the loss of zero dislocations are shown. The first set of crucibles had barium rim coatings (inner and outer surfaces) that stopped approximately 0 mm but not more than 5 mm above the melt line ("short rim coatings"), while the second set contained barium rim coatings (approximately three times the width of the melt line) that extended to approximately 1 inch below the melt line on the inner and outer surfaces ("extended rim coatings"). As shown in Figure 8, the extended rim coatings reduced melt oscillations, particularly in the refilled ingots, and reduced necking and pop-out events. These refilled ingots are prone to time-dependent crucible damage, which is exacerbated by increasing the number of attempts and pop-out events. Reducing these events reduces overall cycle time and reduces overall crucible damage.

[0045] Figure 9 is a graph comparing the frequency of crown / initial body loss of the zero dislocation state (normalized). As shown in Figure 9, it can be seen that the zero dislocation state is maintained more frequently in the crucible with the extended rim coating compared to the crucible with the short rim coating.

[0046] Figure 10 compares the total body ratio and number of attempts for short rim coating and extended rim coating. As shown in Figure 10, fewer attempts are required to form the entire body for the extended rim coated crucible.

[0047] As used herein, the terms "about," "substantially," "essentially," and "approximately," when used in conjunction with a range of dimensions, concentrations, temperatures, or other physical or chemical properties or characteristics, are intended to cover variations that may exist at the upper and / or lower limits of the range of the property or characteristic, for example, variations resulting from rounding, measurement methods, or other statistical variations.

[0048] When introducing elements of this disclosure or embodiments thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprise," "include," "contain," and "have" are intended to be inclusive and mean that there may be additional elements other than the listed elements. The use of specific directional terms (such as "above," "below," and "besides") is for convenience of description and does not require a particular orientation of the items being described.

[0049] Because the above-described structures and methods are susceptible to various modifications without departing from the scope of the invention, all matter contained in the above description and shown in the accompanying drawings is intended to be interpreted as illustrative and not in a limiting sense.

Claims

1. 1. A crucible for holding a silicon melt, comprising: a body having a bottom and a sidewall extending upwardly from the bottom, the bottom and the sidewall defining a cavity for holding a silicon melt, the sidewall having a top, an inner surface and an outer surface, the sidewall having a height extending from the bottom to the top of the sidewall, the body comprising synthetic quartz; and a coating disposed on a first interior surface region of the interior surface of the sidewall, the coating comprising magnesium, calcium, strontium, or barium, the first interior surface region being a distance D from the top of the sidewall; １ and the distance D １ is less than the height of said sidewall, A crucible comprising:

2. a second inner surface region of the inner surface of the sidewall extending from the first inner surface region to the bottom of the crucible, the second inner surface region being free of a coating; 2. The crucible of claim 1.

3. The coating is disposed on the first outer surface region of the outer surface of the sidewall, the first outer surface region being a distance D from the top of the sidewall. ２ and the distance D ２ is less than the height of the side wall; 3. The crucible according to claim 1 or 2.

4. the coating is a first coating, a second outer surface region of the outer surface of the sidewall extends from the first outer surface region to the bottom of the body, a second coating is disposed on the first outer surface region and the second outer surface region, the second coating comprises aluminum, and the second coating is disposed between the crucible body and the first coating; 4. The crucible of claim 3.

5. the coating being the only coating disposed on the exterior surface of the sidewall.

4. The crucible of claim 3.

6. the first interior surface region extends to at least the melt line; A crucible according to any one of claims 1 to 5.

7. the first inner surface region extends below the melt line; A crucible according to any one of claims 1 to 5.

8. the coating extends at least 5 mm below the melt line, or at least 10 mm below, at least 25 mm below, at least 50 mm below, at least 100 mm below, or from 5 mm to 100 mm below, from 10 mm to 100 mm below, or from 10 mm to 25 mm below the melt line; 8. The crucible of claim 7.

9. the coating comprises an oxide or carbonate of magnesium, calcium, strontium, or barium; A crucible according to any one of claims 1 to 8.

10. the coating comprises barium oxide; A crucible according to any one of claims 1 to 8.

11. the coating has a thickness of at least about 1 μm; A crucible according to any one of claims 1 to 10.

12. 1. A method of manufacturing a crucible, comprising: providing a body having a bottom and a sidewall extending upwardly from the bottom, the bottom and the sidewall defining a cavity for holding a silicon melt, the sidewall having a top, an inner surface and an outer surface, the sidewall having a height extending from the bottom to the top of the sidewall, the body comprising synthetic quartz; a coating on a first interior surface region of the interior surface of the sidewall, the coating comprising magnesium, calcium, strontium, or barium, the first interior surface region being a distance D from the top of the sidewall; １ and the distance D １ is less than the height of the sidewall. method.

13. applying the coating to a first outer surface region of the outer surface of the sidewall, the first outer surface region being a distance D from the top of the sidewall; ２ and the distance D ２ is less than the height of the side wall; The method of claim 12.

14. the coating is a first coating, a second outer surface region of the outer surface of the sidewall extends from the first outer surface region to the bottom of the crucible, a second coating is disposed on the first outer surface region and the second outer surface region, the second coating comprises aluminum, and the second coating is disposed between the crucible body and the first coating after application of the first coating. The method of claim 13.

15. the coating being the only coating disposed on the exterior surface of the sidewall. The method of claim 13.

16. the first interior surface region extends to at least the melt line; The method according to any one of claims 12 to 15.

17. the coating extends at least 5 mm below the melt line, or at least 10 mm below, at least 25 mm below, at least 50 mm below, at least 100 mm below, or from 5 mm to 100 mm below, from 10 mm to 100 mm below, or from 10 mm to 25 mm below the melt line; 17. The method of claim 16.

18. the coating comprises an oxide or carbonate of magnesium, calcium, strontium, or barium; The method according to any one of claims 12 to 17.

19. the coating comprises barium oxide; The method according to any one of claims 12 to 17.

20. The coating is applied to a thickness of at least about 1 μm. The method according to any one of claims 12 to 19.

21. The inner surface is coated with a coating agent by dipping, chemical vapor deposition, plasma spraying, brushing, aerosol spraying, or pouring. The method according to any one of claims 12 to 20.

22. 1. A method of forming a single crystal silicon ingot, comprising: adding an initial charge of polycrystalline silicon to a crucible; The crucible is a body having a bottom and a sidewall extending upwardly from the bottom, the bottom and the sidewall defining a cavity for holding a silicon melt, the sidewall having a top, an inner surface and an outer surface, the sidewall having a height extending from the bottom to the top of the sidewall, the body comprising synthetic quartz; and a coating disposed on a first interior surface region of the interior surface of the sidewall, the coating comprising magnesium, calcium, strontium, or barium, the first interior surface region being a distance D from the top of the sidewall; １ and the distance D １ is less than the height of the sidewall; heating an initial charge of polycrystalline silicon to form a silicon melt in a crucible; contacting a silicon seed crystal with a silicon melt; and withdrawing a silicon seed crystal to grow a single crystal silicon ingot; method.

23. The coating is disposed on the first outer surface region of the outer surface of the sidewall, the first outer surface region being a distance D from the top of the sidewall. ２ and the distance D ２ is less than the height of the side wall; 23. The method of claim 22.

24. the silicon melt is stabilized in a stabilization step before contacting the silicon seed crystal, the silicon melt forms a melt line within the crucible at an interface between a surface of the melt and the crucible, and the first inner surface region extends to at least the melt line; 24. The method of claim 22 or 23.

25. the silicon melt is stabilized in a stabilization stage prior to contacting the silicon seed crystal, the silicon melt forming a melt line within the crucible at an interface between a surface of the melt and the crucible, and the first interior surface region extending below the melt line; Claim 22 or claim 23 How to do it.

26. the melt line has a width, and the coating extends below the melt line by at least one time the width of the melt line, or at least five times the width of the melt line, or from one time to ten times the width of the melt line, or from one time to five times the width of the melt line; 26. The method of claim 25.

27. the coating extends at least 5 mm below the melt line, or at least 10 mm below the melt line, or at least 25 mm below, or at least 50 mm below, or at least 100 mm below, or from 5 mm to 100 mm, or from 10 mm to 100 mm, or from 10 mm to 25 mm below the melt line; 27. The method of claim 26.

28. the coating comprises an oxide or carbonate of magnesium, calcium, strontium, or barium; The method according to any one of claims 22 to 27.

29. the coating comprises barium oxide; The method according to any one of claims 22 to 27.

30. The coating is applied to a thickness of at least about 1 μm.

30. The method according to any one of claims 22 to 29.

31. the coating is a first coating, and the crucible includes a second coating disposed on at least a portion of the exterior surface of the body. The method according to any one of claims 22 to 30.

32. the second coating comprises aluminum; 32. The method of claim 31 .

33. the coating being the only coating disposed on the exterior surface of the body; The method according to any one of claims 22 to 30.

34. adding a barium source to the polycrystalline silicon charge or silicon melt prior to pulling the silicon melt to modify crucible properties during ingot growth; The method according to any one of claims 22 to 33.

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