CN210048876U

CN210048876U - Conversion fitting for Czochralski growth apparatus

Info

Publication number: CN210048876U
Application number: CN201822169555.5U
Authority: CN
Inventors: K·R·瓦扬古; R·马伦; S·J·图尔凯蒂
Original assignee: Gtat Co
Current assignee: Gtat Co
Priority date: 2017-12-21
Filing date: 2018-12-21
Publication date: 2020-02-11
Anticipated expiration: 2028-12-21
Also published as: CN109943883B; CN109943883A; TWI789471B; TWM586276U; WO2019126413A1; TW201928129A

Abstract

The utility model provides a firewood kellas base growing device conversion accessory, the utility model relates to a growing device conversion accessory and be used for improving and the method of conversion firewood kellas base growing device, especially convert batch firewood kellas base growing device into continuous firewood kellas base growing device. In particular, a separating valve is provided between the upper and lower hoppers in order to maintain conditions within the lower hopper when the upper hopper is being refilled.

Description

Conversion fitting for Czochralski growth apparatus

Technical Field

The utility model relates to a device conversion accessory for converting a Czochralski growth device into a continuous Czochralski growth device.

Background

One of the most efficient and economical processes for preparing single crystal silicon ingots of material for the manufacture of integrated circuits and photovoltaic solar cells is the Czochralski (CZ) process. In a typical CZ process, a charge of silicon is placed in a crucible and melted to its liquid state, typically at a temperature of about 1416 ℃. The small crystalline silicon seed crystal having the predetermined crystalline orientation is then lowered to contact the melt surface and then gradually withdrawn. By appropriate control of the temperature, the liquid silicon freezes on the seed crystal, with the same orientation as the seed crystal. The seed is then slowly raised from the melt to form a growing silicon ingot having an overall cylindrical shape with a final length of 1 meter or more and a diameter of several hundred millimeters.

Generally, two types of CZ techniques are known, commonly referred to as the czochralski batch process and the continuous czochralski process. In a batch CZ, in a heated crucible, the amount of charge material required for the growing silicon ingot is melted at the start of the process and an ingot is pulled to substantially deplete the crucible. The crucible can then be discarded, or the crucible can be refilled and the process repeated to grow additional silicon ingots, sometimes referred to as a semi-batch process. In addition, a batch recharge process may be used in which the growth of the ingot is stopped, feedstock is added to the crucible, and then growth is resumed. In both batch cases, no feedstock material was added during ingot growth. Furthermore, the number of ingots and their length is generally limited by the size of the crucible. In contrast, in the Continuous Czochralski (CCZ) growth process, the charged material is continuously or periodically replenished during the growth process, and thus, a plurality of ingots can be drawn at a time from one crucible replenished during the growth. Further, since the crucible is replenished during growth, a longer and higher quality ingot can be pulled out in one operation. The crucible is discarded after only a few ingot cycles and replaced with a new crucible. The growth of multiple longer length ingots in a single operation provides economic and procedural advantages, but requires a growth apparatus and apparatus of a significantly different type than those available for batch CZ method growth.

SUMMERY OF THE UTILITY MODEL

The utility model relates to a growing device conversion accessory for with the firewood kellas base growing device, especially batch firewood kellas base growing device converts continuous firewood kellas base growing device into. The growing apparatus conversion kit including a feeder kit comprises: a feeder connectable to the growth chamber and positioned to feed solid feedstock into the growth chamber; a discharge hopper connected to the feeder and positioned to feed solid material into the feeder; at least one upper hopper removably attached above the lower hopper and positioned to feed solid feedstock into the lower hopper; and a feed splitter valve located between the upper hopper and the lower hopper, the feed splitter valve constituting a condition to be maintained in the lower hopper when the upper hopper is being refilled. Furthermore, a shut-off valve may also be located between the upper hopper and the lower hopper. In some embodiments, the growing device conversion kit further comprises a feeder port configured to be located in a sidewall of the growing chamber of the batch of Czochralski growing devices and configured to couple to the feeder kit. In some embodiments, the growth apparatus conversion kit further comprises a feed nozzle configured to be fixedly positioned within the growth chamber of the batch chacolski growth apparatus to direct the solid feedstock from the feed kit into the crucible of the growth chamber. The feed nozzle has an inclined lower end for receiving the solid feedstock from the feeder and feeding the solid feedstock into the crucible.

The present invention further relates to a method, wherein a batch-wise czochralski growth apparatus having a growth chamber is provided, comprising: a chamber housing having a top wall and at least one side wall; a crucible containing melt located within the chamber housing; and a pulling mechanism retractably supporting a seed crystal for contacting the melt. The method further includes providing a growing device conversion kit including a feeder kit, comprising: a feeder connectable to the growth chamber and positioned to feed solid feedstock into the growth chamber; a discharge hopper connected to the feeder and positioned to feed solid material into the feeder; at least one upper hopper removably attached above the lower hopper and positioned to feed solid feedstock into the lower hopper; and a feed splitter valve located between the upper hopper and the lower hopper, the feed splitter valve constituting a condition to be maintained in the lower hopper when the upper hopper is being refilled. The method further includes coupling the feeder subassembly of the growth device conversion subassembly to the sidewall of the growth chamber. In some embodiments, the growing device conversion assemblage further comprises a feed port, coupling the feeder assemblage comprises positioning the feed port in a sidewall of the growing chamber of the batch of the Czochralski growing apparatus and coupling the feeder of the feeder assemblage to the feed port. In some embodiments, the growth apparatus conversion kit further comprises a feed nozzle, and the method further comprises positioning the feed nozzle stationary within the growth chamber of the batch chacolas-based growth apparatus to direct the solid feedstock from the feed nozzle into the crucible of the growth chamber. The feed nozzle has an inclined lower end for receiving the solid feedstock from the feeder and feeding the solid feedstock into the crucible. In this way, the method provides for converting a Czochralski growing apparatus, in particular a batch Czochralski growing apparatus, into a continuous Czochralski growing apparatus.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the invention as claimed.

Drawings

The specific embodiments herein may be better understood by reference to the following description taken in conjunction with the accompanying drawings in which like reference numerals identify identical or functionally similar elements, and in which:

fig. 1 is a view of an embodiment of a growing device conversion kit of the present invention.

Fig. 2 is an exploded view of an embodiment of a growing device conversion kit according to the present invention.

Fig. 3 illustrates an example method for converting a batch chacolski growth apparatus to a continuous chacolski growth apparatus in accordance with a specific embodiment of the present invention.

It should be understood that the above-described drawings are not necessarily to scale and that, in some instances, somewhat simplified representations of various preferred features are possible which illustrate the basic principles of the disclosure. The specific design features of the present disclosure, including, for example, specific dimensions, orientations, locations, and shapes, will be determined in part by the particular intended application and use environment.

Detailed Description

As described above, the batch CZ method growing apparatus is very different from the CCZ method growing apparatus in structure and operation. As a result, the continuous growth process in a batch growth apparatus requires significant and, in some cases, costly modifications to the apparatus. For example, it is necessary to modify a conventional batch-wise Czochralski growing apparatus to include means for adding additional charge to the melt in a continuous or semi-continuous manner without adversely affecting the properties of the growing ingot. This may also require providing access to the interior of the growth chamber, such as by adding ports that are not typically found in most batch CZ devices. Other important modifications may also be required to account for mechanical and thermal variations due to relatively cold feedstock entering the system during the ingot growth phase. In addition, to reduce the adverse effect of this supplemental activity on simultaneous crystal growth, it may be preferable to replace the quartz crucible conventionally used in batch CZ with a crucible having an outer or annular melting zone into which the added material is fed and a separate inner growth zone from which the silicon ingot is pulled, as is more typical for CCZ growth apparatus. Otherwise, the length and/or number of ingots that can be grown may be limited by the crucible size. Other major structural and procedural modifications may also be required. Thus, operations that wish to grow silicon by CCZ often necessitate the purchase of a separate growth apparatus specifically designed for this purpose, resulting in significant costs and requiring additional physical operating space. Currently, there is no viable solution available for efficiently and effectively converting an existing batch CZ growing apparatus to a CCZ growing apparatus.

The utility model relates to a conversion accessory and method for reequiping batch chacolas base method growing device and turning into continuous chacolas base method growing device with this growing device. Although the assembly and method are most particularly useful for converting from a batch of Czochralski plants to a continuous plant, the techniques described herein can also be used to upgrade various types of continuous Czochralski growing apparatus. Thus, the Czochralski growth apparatus to be retrofitted may be any apparatus known in the art and may have a variety of different types of configurations and components as required to produce ingots, particularly silicon ingots. Preferably, the growth apparatus is a batch-wise Czochralski growth apparatus configured to produce silicon ingots in a step-wise process, wherein ingot growth is interrupted in order to replenish the crucible with additional feedstock to prepare additional ingots.

Typically, the Czochralski growth apparatus to be retrofitted comprises a growth chamber in which an ingot, such as a silicon ingot, can be prepared. In particular, the growth chamber includes a chamber housing having a top wall and one or more side walls formed to provide a heatable space containing the feedstock of the crucible. For example, the crucible may contain a pre-charge containing silicon, which is then melted in the crucible within the growth chamber. The crucible may be supported from below by one or more susceptors and may be rotated if desired, and may be any crucible for crystal growth known in the art that is capable of containing solid and liquid materials, particularly solid and liquid silicon. For example, the crucible may be a quartz crucible, or may be a graphite crucible containing a quartz lining. The crucible can also have any cross-sectional shape depending on, for example, the geometry of the crystal growth system, but typically has a circular cross-sectional shape.

In some embodiments, the crucible comprises at least two zones, each separated by a wall or other separation means providing restricted fluid communication between the zones with at least one opening, such as a notch, aperture or tube. For example, the crucible may include a wall that divides it into two regions, an inner region, referred to herein as the inner growth region, and an outer region, referred to herein as the outer feed region. These regions are in fluid communication with each other. The inner region is where the growth of the ingot begins and the ingot is grown (e.g., pulled), while the outer region feeds additional material into the inner region as the ingot grows. Thus, fresh material may enter from the external feed zone as material is removed from the internal growth zone by the crystallization process. Preferably, the inner growth zone and/or the outer feed zone contain a solid pre-charge comprising silicon to be melted therein, and may also contain at least one dopant material including, for example, phosphorus, boron, gallium, indium, aluminum, arsenic or antimony.

The apparatus to be retrofitted and converted also includes at least one system from which a crystal ingot can be grown. For example, the apparatus may further include a pulling mechanism including a retractable cable on which a small seed crystal, such as a silicon crystal, is supported. Using this mechanism, the seed crystal having a predetermined crystalline orientation can be lowered into contact with the molten material (e.g., raw material) contained in the crucible and then gradually withdrawn. By appropriate control of the temperature, the liquid material freezes on the seed crystal in the same orientation as the seed crystal, thereby initiating growth of the ingot. The seed crystal is then slowly raised from the melt to form a growing crystal ingot having the desired final length and diameter. One or more load cells supporting the pulling mechanism may also be used, along with a control device responsive to the load cells for activating the supply of feedstock from the solid feedstock delivery system to the growing device.

As described above, a feedstock pre-charge is typically supplied to a crucible in a growth chamber and melted, and then grown from the melt. In some embodiments, the Czochralski growth apparatus to be retrofitted (e.g., a batch CZ method growth apparatus) may further comprise a system for delivering feedstock into the crucible to provide a pre-charge when growth is not occurring. Any pre-charge delivery system capable of providing a feedstock such as silicon (including metallurgical grade silicon or solar grade silicon), which may also include at least one dopant material, for example, phosphorus, boron, gallium, indium, aluminum, arsenic, or antimony, may be used before or during or after growth. For example, solid feedstock as a pre-charge may be provided via gravity feed from a hopper through a feed tube that is capable of transporting the feedstock from the hopper into a crucible in a growth chamber. A feed port in the chamber housing, such as a feed port in the top wall, may provide a passage through which the feeder delivers the pre-charge. The feed port may provide a seal so that conditions within the growth chamber may be maintained while supplying the pre-charge to the crucible.

The apparatus to be retrofitted may further comprise a heat shield positioned above the crucible. The shield is configured to protect the growing ingot from overheating because the molten charge is held in the crucible and is therefore made of or includes a material having a low thermal conductivity that can withstand the high temperatures and conditions within the growing apparatus. Various types of thermally insulating shields are known in the art, and any of these may be used in the growing apparatus. The size and shape will depend on the geometry of the growing device. For example, for a crucible having a circular cross-sectional shape, and for forming a silicon ingot having a substantially circular cross-sectional shape, the thermally-insulated shield preferably also has a circular cross-sectional shape and is typically geometrically cylindrical or conical. In particular, the heat shield may have an inverted conical shape with a cross-sectional area at the top of the shield greater than the cross-sectional area at the lower end and a diameter at the lower end large enough to pass the growing ingot.

According to the utility model discloses a concrete embodiment provides growth device conversion accessory to turn into continuous faggots method growth device with batch faggots method growth device. The growth apparatus conversion assembly includes a feeder assembly for providing solid feedstock while the silicon ingot is growing, and may also include additional assemblies, as will be described in more detail below. The feeder appendage is configured to be connected or otherwise connected to a growth chamber of a batch Czochralski growing apparatus to enable continuous feeding of feedstock while growing ingots. Preferably, the feeder appendage is configured to be attached to a sidewall of a chamber shell of a growing apparatus at a location where addition of feedstock during growth will have minimal impact on the ingot growth process or the properties of the resulting grown ingot.

In particular, the feeder attachment of the growing apparatus conversion attachment of the present invention comprises a feeder, a lower hopper and at least one upper hopper. In some embodiments, the feeder appendage may be connected to a growth chamber of a batch of the laccolas-based device at the feeder, which is configured to deliver the solid feedstock into the growth chamber, as described in more detail below. The lower hopper is connected to the feeder and positioned to feed the solid material into the feeder, preferably from above (i.e. gravity feeding). Other methods of feeding solid feedstock into a lower hopper may also be used, such as a conveyor or feeding system from a remote upper hopper. Furthermore, an upper hopper is connected to the lower hopper and positioned to feed solid feedstock into the lower hopper, also preferably by gravity feeding from above. In this way, the solid feedstock contained in the upper hopper can be fed into the lower hopper, which can then enter the feeder to be delivered into the growth chamber of the Czochralski growth apparatus.

The upper and lower hoppers are containers for holding solid feedstock and may have any shape or configuration known in the art. Preferably, the hopper has a cylindrical upper portion and a funnel-shaped conical lower portion and has an opening (e.g., a spout) through which the solid feedstock can pass. A cover or lid may also be included to prevent dust or other contaminants from entering the solid feedstock. In addition, the upper and lower hoppers may be the same or different, and their capacity may vary depending on, for example, cost, available space, and the size and number of ingots to be prepared. In some embodiments, the upper hopper may be smaller than the lower hopper. In this way, a sufficiently high capacity may be provided in the lower hopper to grow the desired ingot, while the lower capacity may be used in the upper hopper for ease of removal, as described below. Furthermore, the lower hopper should be able to withstand conditions such as vacuum and/or heat as needed to provide solid feedstock properly adjusted into the feeder and then into the growth chamber of the batch Czochralski growing apparatus.

Furthermore, in particular embodiments of the present invention, the upper hopper can be removed from the lower hopper, for example during feeding of solid feedstock from a feeder to the growth chamber. In particular, the feeder appendage of the growing device conversion appendage may comprise an upper hopper that may be configured to be separated from a lower hopper for transport or movement from its position to provide raw material to the lower hopper. For example, the upper hopper may be physically separated from the lower hopper and transported or otherwise transported to a location where it may be refilled or used for maintenance/repair of the hopper fitting. Alternatively or additionally, in some embodiments, depending on the relative size (i.e., refilling multiple feeders on a large hopper), the upper hopper may be maneuvered laterally away from the lower hopper (e.g., moved along a track) or pivoted (e.g., rotated about a pivot axis) to a position where solid feedstock may no longer be transferred into the lower hopper, or to a position where a different lower hopper is refilled. In this second position, refilling or other operations of the loading hopper may occur. If the feeder accessory comprises a plurality of upper bins, separation of one upper bin may occur, followed or accompanied by replacement with a different upper bin (e.g., by a turntable or other means).

In order to maintain conditions in the lower hopper when the connected upper hopper is removed, the feeder accessory further comprises a feed split valve between the connected upper and lower hoppers. In this way, if the upper hopper is to be removed, the feed split valve can be closed and/or sealed, thereby maintaining the conditions provided within the lower hopper. When the removed upper hopper is reconnected or replaced, the valve can be reopened, reestablishing the conditions in the feed assembly, including in both hoppers.

Additionally, a feed shut-off valve (also sometimes referred to as a discharge valve or a discharge valve) may be included between the upper and lower hoppers to provide a flow of solid feed that may be regulated and adjusted. For example, with the feed split valve open, the feed shut-off valve may be opened to vary the flow rate of solid feed into the lower hopper. If the upper hopper is to be removed, the feed can be stopped first by closing the feed shut-off valve, and then the feed split valve can be closed to maintain conditions in the lower hopper. The feed shut-off valve also prevents solid feed material from interfering with the operation of the isolation valve.

As described above, the feeder attachment of the growing apparatus conversion attachment includes a feeder for delivering solid feedstock into the growing chamber, and more particularly into the crucible of a batch-type scotch-based growing apparatus, which is to be converted into a continuous scotch-based growing apparatus. For example, the feeder may be a trough system by which a controlled amount of solid silicon feedstock is supplied to the crucible. The feeder may comprise at least one delivery point suspended from the crucible. When the crucible includes an inner growth zone and an outer feed zone, the feeder preferably provides material to the outer feed zone of the crucible to minimize interference with the molten silicon from which the ingot is grown or pulled.

In more detail, the feeder of the growing apparatus conversion kit delivers the solid feedstock into the growing chamber, and a variety of different types of feeders may be used. For example, the feeder may include a feeder tray that is either insertable into the growth chamber or movable back from the growth chamber into the feeder subassembly. In one embodiment, the feeder tray may be movable for insertion into the growth chamber while the feeder itself is stationary. In other embodiments, the feeder tray is stationary relative to the feeder and the feeder (and thus the corresponding feeder accessory) may be movably positioned along the feeder track. In this manner, the feeder appendage and feeder may be appropriately positioned to connect to the growth chamber of a batch chacolas-based growing apparatus and provide solid feedstock into the growth chamber.

The feed tray may be formed of any material known in the art capable of withstanding the temperatures and conditions in a high temperature crystal growth furnace, including, for example, high modulus, non-contaminating materials such as silicon carbide. Preferably, the feed tray comprises a receiving portion, wherein the raw material is received from the lower hopper, and an injector portion connected to the receiving portion, which injector portion may be inserted into the growth chamber, for example through a feed port and/or a separation valve as described below. The spout of the lower hopper may be located within the side wall of the receiving portion. In some embodiments, the injector portion has a cross-section that is smaller than a cross-section of the receiving portion. Further, the injector portion may have a lower end portion of concave cross-sectional shape, including, for example, a V-shape with a wall opposite the vertical direction. The slope of the concave bottom may vary depending on, for example, the amount of feedstock fed into the growth chamber. For example, the walls of the injector portion may have a slope between about 30 ° and about 60 °. Furthermore, the receiving portion of the feeder tray may be supported by a vibrator, which assists in conveying the raw material. For example, the vibrator may be supported on a hopper of the container, and the hopper may be supported in the feeding chamber by at least one load cell capable of measuring the amount of material present. Thus, the feed tray may be a vibratory feeder with vibration induced solid feeding motion along the feed tray. Alternatively, the feed tray may be a rotary feed tube configured to move the solid feed along the axis of rotation.

The feeder may further comprise one or more telescoping tubes to provide expansion and contraction as the feeder accessory and feeder are moved relative to the growth chamber along the feeder track. In this way, by displacement of the telescopic tube, the feeder can be retracted or moved towards the growth chamber without disconnecting the feeder from the growth chamber. In addition, for a vibrating feed tray, the bellows may also provide damping characteristics to prevent the transfer of vibrational energy to the growth chamber, which may lead to defects in the growing ingot. Furthermore, if desired, a shielding system may also be used, interposed between the feed tray and the telescopic tube, to protect the telescopic tube from any potentially loose solid material.

In some embodiments, the growing device conversion accessory of the present invention further comprises a chamber isolation valve configured to maintain conditions within the growing chamber when the feeder accessory is removed. In this way, the process conditions (e.g., ingot growth conditions) present on one side of the valve can be separated from the different process conditions (e.g., feedstock maintenance conditions) on the other side. As will be appreciated by those skilled in the art, a variety of different types of valves may be used, such as slide valves, gate valves, wafer valves, and the like. For example, the chamber isolation valve may be connected to a feed port in the growth chamber, as will be discussed in more detail below, or may be connected to a feeder of a feeder accessory. In a preferred embodiment, the feeder accessory includes a chamber isolation valve that is connected to the feeder to isolate conditions present within the feeder accessory. For this example, the feeder appendage may be vacuum sealed to the growth chamber at the chamber isolation valve so that the feeder may be inserted into the growth chamber, and may also be moved back into the feeder appendage from the growth chamber through the chamber isolation valve. The valve may be any valve known in the art, but is preferably a gate valve having an expandable water-cooled gate, such as those described in U.S. patent application publication nos. 2011/0006235,2011/0006236 and 2011/0006240, which are fully incorporated herein by reference. While the use of a separate valve may be advantageous in some embodiments, the use of a valve is optional, and in another embodiment of the invention, the growth system does not include any separate valve.

In some embodiments, the growth apparatus conversion assemblage further includes a feed port configured to be positioned in the chamber shell of the growth chamber and through which feedstock material, such as silicon, is delivered as the silicon ingot grows. Although the feed port may be provided anywhere in the chamber housing, including in at least one of the side walls or the top wall, depending on, for example, the configuration of the batch-size Czochralski growing apparatus, it is preferred that the feed port be provided in a wall of the chamber wall of the lateral growth chamber to facilitate the delivery of the feedstock. Furthermore, it is particularly preferred that the feed opening is located at a height in the side wall of the growth chamber such that the raw material is fed into the crucible without significant influence on the melt formed therein. For example, preferably the feed port is positioned such that feedstock enters the growth chamber from a feeder of the feeder fitting at a height substantially similar to the height of the crucible. In addition, it is also preferred that the feed opening is positioned such that the raw material enters the crucible substantially horizontally. For example, the feeding port is preferably at such a height that the center of the port forms the entire conveying path, which has an angle between 0 ° (i.e. horizontal) and about 45 °, more preferably between about 0 ° and about 30 °, even more preferably between about 0 ° and about 20 °. Therefore, a slight incline is preferred so that the feedstock enters the crucible slowly and consistently without binding or clogging, but not at a sufficiently high velocity to cause splattering or spring back. In addition, the height and/or angle of the feed path may be adjusted within these parameters, including during material transport. Make the raw materials with low height and entrance angle carry from the side of growing chamber through the location feed inlet, can use the utility model discloses a growing device conversion accessory converts continuous firewood czochralski growth process from batch firewood czochralski growing device to produce the spindle that has improved overall performance.

In some embodiments, the growing apparatus conversion kit further comprises a feed port secured in place within the growth chamber of the batch of czochralski growing apparatuses. The feed port is configured to receive a solid feed from a feeder of the feeder subassembly and direct the feed into a crucible in the growth chamber. For example, the feed opening may have a sloped lower end and a spout located above the crucible so that raw material provided from the feeder fitting may enter the feed opening and be added to the crucible without substantial splashing. The slope of the lower end of the feed opening may vary depending on, for example, the height of the feed opening above the crucible and the desired rate of addition of raw material. For example, the inclined lower end may be inclined at an angle between about 30 ° and about 60 °. For a crucible having an inner zone and an outer zone, it is preferred that the spout of the feeding opening is arranged above the outer feeding zone. The feedbox may comprise any material known in the art capable of withstanding the temperatures and conditions in a high temperature crystal growth furnace, including, for example, high modulus, non-contaminating materials such as silicon carbide.

Specific examples of growth device conversion kits and kits of the present invention are shown in figures 1-3 and discussed below. It will be apparent to those skilled in the art, however, that these are merely illustrative and not restrictive, being presented by way of example only. Many modifications and other embodiments are within the scope of one of ordinary skill in the art and are contemplated as falling within the scope of the invention. In addition, those skilled in the art will appreciate that the specific configuration is exemplary and that the actual configuration will depend on the particular system. Those skilled in the art will also be able to identify and recognize equivalents to the specific fittings shown, using no more than routine experimentation.

Fig. 1 is a side view of a growing device conversion fitting 100 according to an example of the present invention. As shown, the fittings include a feeder fitting 110, a feed port 160, and a feed port 170. Fig. 2 is an exploded perspective view of a growing device transition fitting 100 without a feed port. As shown, the feeder subassembly 110 includes an upper hopper 120 positioned above a lower hopper 130 and removably coupled to the lower hopper 130. as shown, the lower hopper 130 is positioned above a feeder 140 and coupled to the feeder 140. In this way, solid feed is gravity fed from the upper hopper to the lower hopper and feeder. In this particular example, the upper hopper 120 has a smaller capacity than the lower hopper 130, and both have an overall cylindrical shape with a generally conical funnel-shaped spout. The upper hopper 120 includes a lid 122 at the top and also includes a coupler 124, the coupler 124 being attachable to and detachable from the lower hopper. A feed split valve 150 is located between the upper hopper 120 and the lower hopper 130, when open, allowing both hoppers and feeders to be under similar feeding conditions (temperature, vacuum, etc.), and when closed, splitting the lower hopper feeding from the upper hopper, allowing the upper hopper to be removed without changing the feeding conditions. In addition, a feed shutoff valve 152 is also positioned between the hoppers, allowing the flow of solid feed from the upper hopper 120 to the lower hopper 130 to be interrupted or adjusted as needed.

In the particular embodiment shown in fig. 1 and 2, the feeder 140 of the feeder attachment 110 may be connected to a housing 190 of a batch-sized scotch-based growing apparatus to be retrofitted and converted to a continuous scotch-based growing apparatus. In particular, the feeder accessory further comprises a rail 145, the feeder 140 being positioned on the rail 145 such that the feeder accessory can be moved along the rail to a position adjacent to the chamber housing. Feeder assembly 110 may optionally rest on base 156 in order to support and position the feeder assembly at the appropriate height for the target chacolas growth device. The height of the base may be static or adjustable.

The feeder 140 includes a feeder tray 142 that receives the solid feedstock from the lower hopper 130 and delivers the feedstock into the growth chamber of the batch chacolas-based growing apparatus. While in some embodiments, in the embodiment shown in fig. 1 and 2, when the feed tray is movable into position to deliver solid feedstock into the growth chamber, the feed tray is stationary relative to the feed assembly and the feed assembly is movable into position along the rails 145. The feeder 140 further comprises a bellows 144, the bellows 144 expanding and contracting and also providing vibration damping as the feeder accessory moves along the track 145 as the feeding tray is operated by vibratory feeding.

As shown in FIG. 1, the growth apparatus transition piece 100 also includes a feed port 160, the feed port 160 being located in a side wall of the chamber housing 190 at a height substantially level with the top of the crucible within the growth chamber. As shown in fig. 1 and 2, the feeder 140 also includes a chamber isolation valve 148, the chamber isolation valve 148 being connectable to the feeding port 160 and when closed, maintaining conditions in the growth chamber when the feeder accessory is removed. The bellows 144 allows the feeder fitting 110 to move relative to the attached chamber isolation valve 148 by expanding and contracting as the feeder 140 moves along the track 145. Thus, the feedwell 142 is inserted into the growth chamber through the feedwell 160. Note that in some embodiments, the feed port may be an optional fitting of the growing apparatus conversion fitting. For example, if the Czochralski growth apparatus to be retrofitted and converted already includes a port in the growth chamber sidewall, the feed port 160 may not be required.

As also shown in fig. 1 and 2, the growing apparatus conversion fitting 100 further includes a feed port 170 fixedly positioned within the growth chamber of the chacolas-based growing apparatus to hang from a crucible 199. As shown, the feed port 170 is positioned at a height to provide a substantially horizontal flow path from the feeder 140. Solid feedstock from the feeder passes through the feed port 160 and then flows through the feed port 170 to be directed into the crucible of the Czochralski growth apparatus. The feed port 170 includes a sloped lower end 172 for receiving solid feedstock from a feeder, which may flow downwardly into the crucible 199.

As mentioned above, the present invention also relates to a method of converting a chacolas-based growing apparatus, in particular a batch CZ growing apparatus, into a continuous chacolas-based growing apparatus. Fig. 3 shows an example simplified procedure of the method. For example, the process 300 may begin at step 305 and continue to step 310 where a batch of Czochralski growth apparatus having growth chambers is provided, as described in more detail above. The particular configuration and assembly of the batch-size Czochralski growth apparatus can vary, and in some embodiments, the growth chamber comprises a chamber housing having a top wall and at least one side wall, a crucible containing a melt positioned within the chamber housing, and a tension mechanism for retractably supporting the seed in contact with the melt.

At step 315, the method further includes providing a growth apparatus conversion assembly including a feeder assembly, as described in more detail above. Any of the above-described fittings may be used in the present method. In some embodiments, the growth apparatus conversion subassembly includes a feeder subassembly, a feed port (which may be optional in some embodiments) positioned in a sidewall of the chamber housing, and a feed port fixedly positioned within the growth chamber for introducing the solid feedstock stream into the crucible. The feeder subassembly includes a feeder connectable to the growth chamber and positioned to feed the solid feedstock into the growth chamber. The feeder assembly also includes a lower hopper coupled to the feeder and positioned to feed the solid material to the feeder, and at least one upper hopper removably coupled above the lower hopper and positioned to feed the solid material into the lower hopper. In addition, the feeder accessory further comprises a feed split valve located between the upper and lower hoppers and configured to maintain conditions in the lower hopper when the upper hopper is filled.

At step 320, the method further includes coupling a feeder fitting of the growth device conversion fitting to a sidewall of the growth chamber, as described in more detail above. In embodiments where the growing apparatus conversion assemblage includes a feeder spout, coupling the feeder spout includes positioning the feeder spout in a sidewall of the growing chamber of the batch of the Czochralski growing apparatus and coupling the feeder of the feeder spout to the feeder spout. The coupling may further include moving the feeder appendage along the track to a position adjacent the chamber shell of the batch of firewood growth apparatuses. The telescopic tube of the feeder can be adjusted by expansion and/or contraction as required to connect the feeder accessory to the growth chamber. An optional base may also be used to adjust the height of the feeder accessory to facilitate coupling. The process 300 then ends at step 325.

It should be noted that while certain steps within process 300 may be optional, as described above, the steps shown in fig. 3 are merely examples for illustration, and certain other steps may be included or excluded as desired. Moreover, while a particular order of steps is shown, such ordering is merely illustrative, and any suitable arrangement of steps may be utilized without departing from the scope of the embodiments herein.

The use of a growing apparatus conversion kit provides significant advantages in a method of converting a batch of Czochralski growing apparatuses into a continuous Czochralski growing apparatus. For example, a user of a batch process that wishes to grow silicon ingots by a continuous process may do so without purchasing an entirely new growth apparatus. Existing batch plants can be retrofitted without significant changes to existing growth chambers and their fittings. Furthermore, the growth apparatus conversion kit of the present invention allows for uninterrupted processing of silicon ingots once coupled to a growth chamber. In particular, since the feeder attachment comprises two solid feedstock hoppers separated by a separating valve, solid silicon can be fed from the upper hopper to the lower hopper through the feeder and into the crucible of the growing apparatus. In growing silicon ingots, the upper hopper may be removed when empty by closing the feed split valve, allowing the same or additional ingot to continue to grow as the upper hopper is refilled. Once filled, the upper hopper may be reconnected, the feed split valve may be opened, and entry into the lower hopper may continue from the upper hopper. This can be repeated several times, all without interrupting the growth process of the silicon ingot. In essence, an ingot of almost infinite length can be grown, as the feedstock is continuously replenished during growth by refilling a removable and separable upper hopper. This is not possible in batch Czochralski processes, where the ingot length is limited by the size of the crucible, and is also not generally achievable in standard continuous Czochralski processes, where the ingot length is limited by the size of the hopper that fills the crucible. Other advantages will be recognized by those of ordinary skill in the art, given the benefit of this disclosure.

The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.

Claims

1. A growing device conversion kit for converting a batch of czochralski growing devices having growing chambers into a continuous czochralski growing device, wherein the growing device conversion kit comprises a feeder kit, comprising:

a feeder connectable to the growth chamber and positioned to feed solid feedstock into the growth chamber;

a discharge hopper connected to the feeder and positioned to feed solid material into the feeder;

at least one upper hopper removably attached above the lower hopper and positioned to feed solid feedstock into the lower hopper; and

a feed splitter valve located between the upper hopper and the lower hopper, the feed splitter valve constituting a condition to be maintained in the lower hopper when the upper hopper is being refilled.

2. The growth apparatus conversion kit of claim 1, wherein the feeder comprises a feed tray having a receiving section for receiving the solid feedstock from the lower hopper and an injector section connected to the receiving section and insertable into the growth chamber.

3. The growing apparatus conversion kit of claim 2, wherein the feed tray is a vibratory feed tray.

4. The growing apparatus conversion kit of claim 2, wherein the feeder tray is a drum feeder tray.

5. The growing device conversion kit of claim 2, wherein the feed tray is movable to be inserted into the growth chamber.

6. The growing device conversion kit of claim 1, wherein the feeder kit is movable along a feeder track.

7. The growing device conversion kit of claim 6, wherein the feeder comprises a telescoping tube configured to expand or contract as the feeder moves along the feeder track.

8. The growing device conversion kit of claim 1, wherein the feeder kit comprises a feed shut-off valve positioned between the upper hopper and the lower hopper.

9. The growing device conversion kit of claim 1, wherein the feeder kit comprises a chamber isolation valve configured to maintain conditions within the growing chamber when the feeder kit is removed.

10. The growing device conversion kit of claim 9, wherein the chamber isolation valve is a gate valve with an expandable water-cooled gate.

11. The growing device conversion kit of claim 9, wherein the chamber isolation valve is connected to the feeder of the feeder kit.

12. The growing device conversion kit of claim 9, wherein the feeder comprises a telescoping tube configured to expand or contract as the feeder moves along the feeder track, and wherein the chamber isolation valve is connected to the telescoping tube of the feeder.

13. The growing device conversion kit of claim 1, further comprising a feeder port configured to be located in a sidewall of the growth chamber of the batch of the Czochralski growing apparatus and configured to couple to the feeder kit.

14. The growing device conversion kit of claim 13, wherein the feeder kit comprises a chamber isolation valve connectable to the feeding port and configured to maintain conditions within the growing chamber when the feeder kit is removed.

15. The growing device conversion kit of claim 14, wherein the feeder comprises a telescoping tube configured to expand or contract as the feeder moves along the feeder track, and wherein the chamber isolation valve is attached to the telescoping tube of the feeder.

16. The growth apparatus conversion kit of claim 13, wherein the feeder comprises a feed tray having a receiving section for receiving the solid feedstock from the lower hopper and an injector section connected to the receiving section and insertable into the growth chamber through the feed port.

17. The growth device conversion kit of claim 1, further comprising a feed nozzle configured to be fixedly positioned within the growth chamber of the batch chacolas-based growth device for directing the solid feedstock from the feed kit into the crucible of the growth chamber.

18. The growing device conversion kit of claim 17, wherein the feed nozzle has a sloped lower end to receive the solid feedstock from the feeder and feed the solid feedstock into the crucible.

19. The growth apparatus conversion kit of claim 17, wherein the crucible comprises at least one wall member separating an inner growth zone and an outer feed zone, the wall member having at least one opening providing restricted fluid communication between the inner growth zone and the outer feed zone, and wherein the feed nozzle directs the feed of the solid feedstock to the outer feed zone of the crucible.

20. The growing apparatus conversion kit of claim 1, wherein the batch of czochralski growing apparatuses comprises:

a chamber housing having a top wall and at least one side wall;

a crucible containing melt located within the chamber housing; and

a pulling mechanism retractably supporting a seed crystal for contacting the melt.

21. The growing device conversion kit of claim 1, wherein the batch of czochralski growing devices further comprises a solid feedstock delivery system located outside the growing chamber, and wherein the feeder kit is a replacement for the solid feedstock delivery system.