WO2020100512A1 - Method for producing single crystal - Google Patents
Method for producing single crystal Download PDFInfo
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- WO2020100512A1 WO2020100512A1 PCT/JP2019/040814 JP2019040814W WO2020100512A1 WO 2020100512 A1 WO2020100512 A1 WO 2020100512A1 JP 2019040814 W JP2019040814 W JP 2019040814W WO 2020100512 A1 WO2020100512 A1 WO 2020100512A1
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- single crystal
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- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B13/00—Single-crystal growth by zone-melting; Refining by zone-melting
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- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/02—Elements
- C30B29/06—Silicon
Definitions
- the present invention relates to a method for producing a single crystal by the FZ method, and more specifically, a method for producing a single crystal in which the remaining raw material crystal rods are reasonably utilized when the growth is stopped during the growth of the single crystal by the FZ method. Regarding the method.
- high-purity silicon wafers manufactured by the FZ method have been used for manufacturing power devices such as high breakdown voltage power devices and thyristors.
- caliber 8 inch (diameter 200 mm), 6 inch (diameter 150 mm), 5 inch (diameter 125 mm), 4 inch (diameter 100 mm) and smaller are manufactured. ..
- a raw material crystal rod is heated and melted by an induction heating coil to form a floating zone, and an upper raw material crystal rod and a lower single crystal rod are relatively lowered with respect to the induction heating coil to form a floating zone.
- the single crystal ingot is grown by moving it (see, for example, Patent Document 1).
- FIG. 3 shows a generally used FZ single crystal production apparatus 30. A method of manufacturing a silicon single crystal using this FZ single crystal manufacturing apparatus 30 will be described.
- a silicon raw material crystal rod 1 a silicon polycrystal rod manufactured by the Siemens method or a silicon single crystal rod manufactured by the CZ method is used.
- the upper shaft 3 of the upper shaft 3 is previously attached to the upper side of the silicon raw material crystal rod 1 (the tail side when becoming a single crystal). A part of it is machined to hold it in the upper holding jig 4, the tip side is machined on the lower side (cone side when it becomes a single crystal) to facilitate seeding, and the straight body part is Machining or the like to obtain a desired diameter may be performed.
- impurities are attached to the surface as it is, and therefore etching or cleaning is generally performed in order to manufacture a high-purity single crystal.
- the silicon raw material crystal rod 1 is held by the upper holding jig 4 of the upper shaft 3 installed in the chamber 20. Then, a single crystal seed (seed crystal) 8 having a small diameter is held by the lower holding jig 6 of the lower shaft 5 located below the silicon raw material crystal rod 1.
- the silicon raw material crystal rod 1 is melted by the induction heating coil 7 and fused to the seed crystal 8. After that, the narrowed portion 9 is formed by the seed narrowing to eliminate dislocation. Then, by lowering the silicon raw material crystal rod 1 and the silicon single crystal 2 while rotating the upper shaft 3 and the lower shaft 5, a floating zone 10 (also referred to as a melting zone or a melt) is formed in the silicon raw material crystal rod 1 and the silicon single crystal 2.
- the silicon single crystal 2 is grown by moving the floating zone 10 to the upper end of the silicon raw material crystal rod 1 and zoning. This growth is performed in an atmosphere in which a small amount of nitrogen gas is mixed with Ar gas.
- an induction heating coil made of copper or silver in which single or multiple winding water for cooling is circulated is used.
- the silicon single crystal may become dislocations on the way before reaching the target weight.
- the weight of the remaining silicon raw material crystal rod becomes larger than expected, and the weight of the remaining silicon raw material crystal rod measured is the minimum product according to the conventional flow of reusing the silicon raw material crystal rod shown in FIG. If the weight is large enough to be acquired, it can be used again for the FZ method.
- a silicon single crystal (hereinafter, simply referred to as a single crystal) having a weight as large as possible from one silicon raw material crystal rod (hereinafter also simply referred to as a raw material crystal rod). It is preferable because it leads to yield improvement and cost improvement. The reason for this is that the silicon raw material crystal rod for producing a single crystal by the FZ method is expensive and occupies a large ratio to the cost of the produced single crystal.
- crystal growth may be stopped midway due to unavoidable dislocations, earthquakes, and stoppages due to momentary blackouts.
- the products of the FZ method are high-mix low-volume production, the required product quantity is very small, and the growth may be stopped midway. In these cases, the remaining weight of the silicon raw material crystal rod becomes large.
- the present invention has been made in view of such a problem, and provides a method for producing a single crystal in which the yield reduction is suppressed by effectively utilizing the remaining raw material crystal rods when the crystal growth is stopped midway.
- the purpose is to
- the present invention forms a floating zone by heating and melting a raw material crystal rod with an induction heating coil, and the raw material crystal rod on the upper side and the single crystal rod on the lower side with respect to the induction heating coil.
- a method for producing a single crystal by the FZ method in which the single crystal ingot is grown by relatively lowering while rotating, and moving the floating zone, When the growth is stopped during the crystal growth and the production of the single crystal by the FZ method is finished, a measurement step of measuring the weight of the remaining raw material crystal rods, The theoretical yield of the single crystal straight body part excluding the cone part and the tail part with respect to the remaining raw material crystal rod of the single crystal rod that can be theoretically produced from the remaining raw material crystal rod is calculated from the measured weight, and the crystal is obtained.
- the diameter of the first single crystal before the growth is stopped in the middle of the growth is less than or equal to the predetermined reference yield, the maximum diameter of the single crystal that can be produced again using the remaining raw material crystal rods is determined, or If the predetermined reference yield is not satisfied, a determination step of determining not to manufacture a single crystal with the remaining raw material crystal rods, When the maximum diameter of the re-manufacturable single crystal is determined, it has a re-manufacturing step of manufacturing a single crystal with the maximum diameter of the re-manufacturable single crystal determined using the remaining raw material crystal rods.
- a method for producing a characteristic single crystal is provided.
- the manufacturing cost can be reduced as compared with the conventional case by not manufacturing the single crystal.
- the diameter of the manufacturable single crystal, and the minimum yield for each diameter of the manufacturable single crystal as the reference yield is predetermined, Can be manufactured from the remaining raw material crystal rods, perform the first calculation process to calculate the theoretical yield of the diameter of the first manufactured single crystal, If the theoretical yield of the diameter of the initially produced single crystal is greater than or equal to the minimum yield determined for each diameter, the same diameter is used as the maximum diameter of the single crystal that can be produced again, and if it is less than the minimum yield determined for each diameter.
- Performing a first determination process of setting a provisional maximum diameter of the single crystal to be one size smaller than the predetermined diameter of the manufacturable single crystal Again, it can be produced from the remaining raw material crystal rods, perform a calculation process to calculate the theoretical yield of the temporary maximum diameter of the single crystal, If the theoretical yield of the provisional maximum diameter of the single crystal is equal to or more than the minimum yield determined for each diameter, the diameter is the maximum diameter of the single crystal that can be manufactured again, and if the minimum yield is less than the minimum yield determined for each diameter, A determination process is performed to reset the provisional maximum diameter of the single crystal to a diameter smaller by one size among the predetermined diameters of the manufacturable single crystals, and the provisional maximum diameter of the reset single crystal is used. Repeating the calculation process and the determination process, if the theoretical yield calculated at the predetermined minimum diameter of the diameter of the manufacturable single crystal is smaller than the minimum yield determined for each diameter, the single crystal should not be manufactured. It is preferable to determine.
- the product yield can be improved more easily and reliably than before, and the manufacturing cost can be reduced.
- the weight of the remaining raw material crystal rod is measured, and from the raw material crystal rod of that weight, the diameter of the first produced single crystal or less, the maximum diameter of the single crystal satisfying the reference yield Since it becomes possible to manufacture a single crystal having an appropriate diameter, it is possible to effectively use the raw material crystal ingot, and it is possible to improve the product yield more than ever before. Further, when the predetermined reference yield is not satisfied, the manufacturing cost can be reduced as compared with the conventional case by not manufacturing the single crystal.
- the inventors of the present invention can suppress the yield reduction by effectively utilizing the remaining raw material crystal rods when the crystal growth is stopped midway. Understood, the present invention was completed.
- a raw material crystal rod is heated and melted by an induction heating coil to form a floating zone, and the upper raw material crystal rod and the lower single crystal rod are relatively rotated with respect to the induction heating coil.
- the method for producing a single crystal by the FZ method in which the single crystal ingot is grown by moving the floating zone to a low temperature, the growth is stopped during the crystal growth, and the production of the single crystal by the FZ method is completed.
- the theoretical yield of the straight body is calculated from the measured weight, the diameter of the first single crystal before the growth is stopped before the growth is stopped during the crystal growth, and the predetermined standard yield is satisfied, the remaining raw material crystals.
- a determination step to determine that the remaining raw material crystal rod does not produce a single crystal is included.
- a remanufacturing step of manufacturing a single crystal with the maximum diameter of the re-manufacturable single crystal determined using the remaining raw material crystal rods is included. And a method for producing a single crystal.
- a judgment standard in the judgment step of the method for producing a single crystal of the present invention for example, a criterion used in the flow of reusing a silicon source crystal ingot as shown in FIG. 1 can be created.
- the diameter of the single crystal that can be manufactured first before the growth is stopped in the middle of crystal growth, the diameter of the single crystal that can be manufactured, and the minimum yield for each diameter of the single crystal that can be manufactured as the reference yield are set in advance. Set (A in FIG. 1).
- the first calculation process is performed to calculate the theoretical yield of the diameter of the first single crystal produced before the growth was stopped at (D in FIG. 1). If the theoretical yield is equal to or higher than the minimum yield preset for each diameter, it is the same.
- the diameter of the single crystal is determined to be the maximum diameter of the single crystal that can be produced again (F in FIG. 1).
- the first determination process for making the diameter smaller is performed (H in FIG. 1).
- the calculation process of calculating the theoretical yield of the provisional maximum diameter of the single crystal is performed, and if the theoretical yield is more than the minimum yield previously determined for each diameter,
- the diameter is defined as the maximum diameter of the single crystal that can be manufactured again, and when the yield is smaller than the minimum yield, the determination processing is performed to reset the temporary maximum diameter of the single crystal to a diameter that is one size smaller than the predetermined diameter (E in FIG. 1). ).
- the calculation process and the determination process are repeated with the temporary maximum diameter of the single crystal reset. If the theoretical yield calculated at the predetermined minimum diameter is smaller than the minimum yield at the minimum diameter, the product is not manufactured (I in FIG. 1).
- the theoretical yield means a single crystal rod that is theoretically manufactured from the remaining raw material crystal rods after the growth is stopped during the crystal growth, except for the cone portion and the tail portion for the remaining raw material crystal rods. It is the yield of the straight body of the crystal.
- the product yield can be improved more easily and reliably than before, and the manufacturing cost can be reduced.
- the weight of the remaining raw material crystal rod is light, for example, the weight of the cone portion and the tail portion is less than the weight, it is apparent that the minimum yield cannot be reached at the same diameter as the diameter of the initially prepared single crystal, A diameter smaller than the diameter of the initially manufactured product can be temporarily determined as the temporary maximum diameter of the single crystal, and the calculation processing and the determination processing can be started from the diameter.
- the diameters of the single crystals that can be manufactured are 8 inches (diameter 200 mm), 6 inches (diameter 150 mm), 5 inches (diameter 125 mm), 4 inches (diameter 100 mm), 3 inches (diameter 75 mm), 60 mm, 2 Inches (diameter 50 mm) and the like can be selected, but the product diameter to be manufactured is not limited to this.
- a single crystal is actually manufactured by the FZ method. Then, when the growth is stopped during the growth due to a power outage, an earthquake or the like (B in FIG. 1), a measurement step of measuring the weight of the remaining silicon raw material crystal ingot is performed (C in FIG. 1).
- the theoretical yield of the single crystal straight body is calculated from the measured weight, and is less than or equal to the diameter of the first single crystal produced before stopping the growth in the course of crystal growth, and the predetermined reference yield is satisfied.
- the temporarily determined diameter is used as the temporary maximum diameter of the single crystal, and the theoretical yield of the diameter is calculated (D in FIG. 1). Then, in comparison with the predetermined minimum yield of the diameter (E in FIG. 1), if the yield is more than the minimum yield, the diameter is set as the maximum diameter of the single crystal that can be manufactured again (F in FIG. 1), and the minimum yield is calculated. If it is smaller, a determination process for resetting the diameter one size smaller than the diameter to the temporary maximum diameter is performed (H in FIG. 1), the theoretical yield is calculated again, and the same comparison as above is performed.
- the re-manufacturing step of manufacturing the single crystal with the determined maximum diameter of the re-manufacturable single crystal is performed using the remaining raw material crystal rods ( G in FIG. 1).
- a general FZ method single crystal manufacturing method can be used as a method of performing a single crystal remanufacturing process using the remaining raw material crystal rods.
- a single crystal is manufactured through a cone process of growing a single crystal rod while expanding it to a desired diameter, and a straight body process of growing the single crystal rod while controlling the diameter of the single crystal rod to a constant diameter after the cone is formed.
- the diameter of the single crystal is expanded to the maximum diameter of the single crystal that can be remanufactured, which has been determined in the determination step, and the single crystal having this diameter is grown.
- a single crystal having a diameter of 8 inches (200 mm) according to the FZ method is determined based on whether the theoretical yield of the single crystal is equal to or higher than the minimum yield determined for each diameter below or smaller than the minimum yield determined for each diameter.
- the remaining raw material crystal rods are used to remanufacture the single crystal having the maximum diameter satisfying the minimum yield defined for each of the following diameters as the reference yield by the flow as shown in FIG. went.
- the determination step of the example it was not determined that the single crystal was not produced.
- the product yield of the example is higher than that of the comparative example, and by using the method for producing a single crystal of the present invention, when the growth is stopped during the crystal growth and the production of the single crystal by the FZ method is completed, The remaining raw material crystal rods can be effectively used, and the product yield can be improved more than ever before. In addition, the manufacturing cost could be reduced by manufacturing a single crystal having the largest possible weight from the remaining raw material crystal rods.
- the present invention is not limited to the above embodiment.
- the above-described embodiment is an exemplification, has substantially the same configuration as the technical idea described in the scope of the claims of the present invention, and has the same operational effect It is included in the technical scope of the invention.
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Abstract
The present invention relates to a method for producing a single crystal by means of an FZ method in which a floating zone is formed by heating and melting a raw material crystal rod by using an induction heating coil, an upper raw material crystal rod and a lower single crystal rod are lowered relative to the induction heating coil while the upper and lower raw material crystal rods are rotated, and the floating zone is moved to grow a single crystal rod, the method being characterized by having: a measurement step for measuring the weight of the remainder of a raw material crystal rod when growth is stopped during growing of the single crystal rod and the production of the single crystal is stopped; a determining step for calculating a theoretical yield of a single crystal straight body section which can be produced from the remainder of the raw material crystal rod, and determining the maximum diameter of the single crystal which can be produced again or determining not to produce the single crystal; and a re-producing step for producing the single crystal again when the maximum diameter of the single crystal which can be produced again is determined. Accordingly, provided is a method for producing a single crystal in which a reduction in yield is suppressed by effectively utilizing the remainder of a raw material crystal rod when growth is stopped while the single crystal rod is growing.
Description
本発明は、ＦＺ法による単結晶の製造方法に関し、更に詳しくはＦＺ法により単結晶を成長させている途中で成長を停止した場合に残りの原料結晶棒を合理的に利用する単結晶の製造方法に関する。
The present invention relates to a method for producing a single crystal by the FZ method, and more specifically, a method for producing a single crystal in which the remaining raw material crystal rods are reasonably utilized when the growth is stopped during the growth of the single crystal by the FZ method. Regarding the method.
従来、高耐圧パワーデバイスやサイリスタ等のパワーデバイス製造用にはＦＺ法により製造された高純度シリコンウェーハが使用されてきた。
Conventionally, high-purity silicon wafers manufactured by the FZ method have been used for manufacturing power devices such as high breakdown voltage power devices and thyristors.
近年では、半導体デバイスの性能向上とコストの低減のため、大口径のシリコンウェーハが求められ、これに伴って大口径シリコン単結晶の育成が要求されている。また、従来の口径の製品の需要もあるので、８インチ（直径２００ｍｍ）、６インチ（直径１５０ｍｍ）、５インチ（直径１２５ｍｍ）、４インチ（直径１００ｍｍ）、それ以下の口径も製造されている。
In recent years, in order to improve the performance of semiconductor devices and reduce costs, large-diameter silicon wafers have been demanded, and accompanying this, the growth of large-diameter silicon single crystals has been required. In addition, since there is a demand for products with conventional caliber, caliber of 8 inch (diameter 200 mm), 6 inch (diameter 150 mm), 5 inch (diameter 125 mm), 4 inch (diameter 100 mm) and smaller are manufactured. ..
ＦＺ法では、原料結晶棒を誘導加熱コイルで加熱溶融して浮遊帯域を形成し、誘導加熱コイルに対して上側の原料結晶棒及び下側の単結晶棒を相対的に下降させ、浮遊帯域を移動させることで単結晶棒を育成する（例えば、特許文献１参照）。
In the FZ method, a raw material crystal rod is heated and melted by an induction heating coil to form a floating zone, and an upper raw material crystal rod and a lower single crystal rod are relatively lowered with respect to the induction heating coil to form a floating zone. The single crystal ingot is grown by moving it (see, for example, Patent Document 1).
図３に、一般的に用いられるＦＺ単結晶製造装置３０を示す。このＦＺ単結晶製造装置３０を用いて、シリコン単結晶を製造する方法について説明する。
FIG. 3 shows a generally used FZ single crystal production apparatus 30. A method of manufacturing a silicon single crystal using this FZ single crystal manufacturing apparatus 30 will be described.
まず、シリコン原料結晶棒１を準備する。シリコン原料結晶棒１としては、シーメンス法により製造されたシリコン多結晶棒又はＣＺ法により製造されたシリコン単結晶棒が用いられる。
First, prepare a silicon raw material crystal rod 1. As the silicon raw material crystal rod 1, a silicon polycrystal rod manufactured by the Siemens method or a silicon single crystal rod manufactured by the CZ method is used.
シリコン原料結晶棒１は上軸３に上部保持治具４にて保持する必要があるので、予め、シリコン原料結晶棒１の上側（単結晶になった時のテール側）には上軸３の上部保持治具４に保持する為に一部を機械加工したり、下側（単結晶になった時のコーン側）には種付けし易いように先端部を機械加工したり、直胴部を所望の直径にするための機械加工などが施されてもよい。機械加工をすると、そのままでは表面に不純物が付着しているので、高純度な単結晶を製造するために、一般的にはエッチングや洗浄がなされる。
Since the silicon raw material crystal rod 1 needs to be held on the upper shaft 3 by the upper holding jig 4, the upper shaft 3 of the upper shaft 3 is previously attached to the upper side of the silicon raw material crystal rod 1 (the tail side when becoming a single crystal). A part of it is machined to hold it in the upper holding jig 4, the tip side is machined on the lower side (cone side when it becomes a single crystal) to facilitate seeding, and the straight body part is Machining or the like to obtain a desired diameter may be performed. When mechanical processing is performed, impurities are attached to the surface as it is, and therefore etching or cleaning is generally performed in order to manufacture a high-purity single crystal.
続いて、シリコン原料結晶棒１をチャンバー２０内に設置された上軸３の上部保持治具４に保持する。そして、直径の小さい単結晶の種（種結晶）８を、シリコン原料結晶棒１の下方に位置する下軸５の下部保持治具６に保持する。
Subsequently, the silicon raw material crystal rod 1 is held by the upper holding jig 4 of the upper shaft 3 installed in the chamber 20. Then, a single crystal seed (seed crystal) 8 having a small diameter is held by the lower holding jig 6 of the lower shaft 5 located below the silicon raw material crystal rod 1.
次に、誘導加熱コイル７によりシリコン原料結晶棒１を溶融して、種結晶８に融着させる。その後、種絞りにより絞り部９を形成して無転位化する。そして、上軸３と下軸５を回転させながらシリコン原料結晶棒１とシリコン単結晶２を下降させることで浮遊帯域１０（溶融帯あるいはメルトともいう）をシリコン原料結晶棒１とシリコン単結晶２の間に形成し、当該浮遊帯域１０をシリコン原料結晶棒１の上端まで移動させてゾーニングし、シリコン単結晶２を成長させる。この成長は、Ａｒガスに微量の窒素ガスを混合した雰囲気中で行われる。
Next, the silicon raw material crystal rod 1 is melted by the induction heating coil 7 and fused to the seed crystal 8. After that, the narrowed portion 9 is formed by the seed narrowing to eliminate dislocation. Then, by lowering the silicon raw material crystal rod 1 and the silicon single crystal 2 while rotating the upper shaft 3 and the lower shaft 5, a floating zone 10 (also referred to as a melting zone or a melt) is formed in the silicon raw material crystal rod 1 and the silicon single crystal 2. The silicon single crystal 2 is grown by moving the floating zone 10 to the upper end of the silicon raw material crystal rod 1 and zoning. This growth is performed in an atmosphere in which a small amount of nitrogen gas is mixed with Ar gas.
上記誘導加熱コイル７としては、銅又は銀からなる単巻又は複巻の冷却用の水を流通させた誘導加熱コイルが用いられている。
As the induction heating coil 7, an induction heating coil made of copper or silver in which single or multiple winding water for cooling is circulated is used.
目的の重量のシリコン単結晶に到達した段階で、テールを形成する工程となり、成長を停止し、シリコン原料結晶棒と切り離す。
▽ When the silicon single crystal with the target weight is reached, the process of forming the tail is started, the growth is stopped, and the silicon raw material crystal rod is separated.
しかしながら、目的の重量に到達する前にシリコン単結晶が途中で有転位化してしまう場合もある。この場合には、残りのシリコン原料結晶棒の重量は想定よりも大きくなり、図２に示す従来のシリコン原料結晶棒の再利用のフローに従い、測定した残りのシリコン原料結晶棒の重量が最低製品重量を取得できるほど大きい場合には、再度、ＦＺ法に利用することができる。
However, in some cases, the silicon single crystal may become dislocations on the way before reaching the target weight. In this case, the weight of the remaining silicon raw material crystal rod becomes larger than expected, and the weight of the remaining silicon raw material crystal rod measured is the minimum product according to the conventional flow of reusing the silicon raw material crystal rod shown in FIG. If the weight is large enough to be acquired, it can be used again for the FZ method.
ＦＺ法によるシリコン単結晶の結晶成長においては１本のシリコン原料結晶棒（以下、単に原料結晶棒ともいう）からできるだけ大きな重量のシリコン単結晶（以下、単に単結晶ともいう）を製造することが、歩留り、コスト改善に繋がり好ましい。この理由は、ＦＺ法による単結晶の製造用のシリコン原料結晶棒は高価であり、製造する単結晶のコストに対して大きな比率を占めているからである。
In the crystal growth of a silicon single crystal by the FZ method, it is possible to manufacture a silicon single crystal (hereinafter, simply referred to as a single crystal) having a weight as large as possible from one silicon raw material crystal rod (hereinafter also simply referred to as a raw material crystal rod). It is preferable because it leads to yield improvement and cost improvement. The reason for this is that the silicon raw material crystal rod for producing a single crystal by the FZ method is expensive and occupies a large ratio to the cost of the produced single crystal.
しかしながら、不可避的な有転位化や地震、瞬停による停止により、途中で結晶成長を停止させることがある。また、ＦＺ法の製品は多品種少量生産であり、必要な製品量が随分と少なく、途中で成長を停止させる場合がある。これらの場合にはシリコン原料結晶棒の残りの重量が大きくなってしまう。
However, crystal growth may be stopped midway due to unavoidable dislocations, earthquakes, and stoppages due to momentary blackouts. Further, the products of the FZ method are high-mix low-volume production, the required product quantity is very small, and the growth may be stopped midway. In these cases, the remaining weight of the silicon raw material crystal rod becomes large.
このような場合には、残りのシリコン原料結晶棒を再度、ＦＺ法に利用することで少しでも製品を製造することは有効であるが、シリコン原料結晶棒の重量は最初に比べて軽くなっているので、このようなシリコン原料結晶棒から製品を再製造した場合、製品部分に対して製品にならないコーン部やテール部の比率が高くなり必然的に歩留りは低下してしまう。
In such a case, it is effective to manufacture the product as much as possible by utilizing the remaining silicon raw material crystal rods for the FZ method again, but the weight of the silicon raw material crystal rods becomes lighter than at the beginning. Therefore, when a product is remanufactured from such a silicon raw material crystal ingot, the ratio of the cone portion and the tail portion which are not the product to the product portion becomes high, and the yield is inevitably lowered.
本発明はこのような課題に鑑みなされたもので、途中で結晶成長を停止させた場合に、残りの原料結晶棒を有効に利用することで歩留り低下を抑制した単結晶の製造方法を提供することを目的とする。
The present invention has been made in view of such a problem, and provides a method for producing a single crystal in which the yield reduction is suppressed by effectively utilizing the remaining raw material crystal rods when the crystal growth is stopped midway. The purpose is to
上記課題を解決するため、本発明は、原料結晶棒を誘導加熱コイルで加熱溶融して浮遊帯域を形成し、前記誘導加熱コイルに対して上側の前記原料結晶棒及び下側の単結晶棒を回転させながら相対的に下降させ、前記浮遊帯域を移動させることで前記単結晶棒を育成するＦＺ法による単結晶の製造方法であって、
結晶成長途中で成長を停止し、ＦＺ法による単結晶の製造を終了した場合に、残りの原料結晶棒の重量を測定する測定工程と、
前記残りの原料結晶棒から理論的に製造できる単結晶棒の前記残りの原料結晶棒に対するコーン部とテール部を除いた単結晶直胴部の理論歩留りを前記測定した重量から計算し、前記結晶成長途中で成長を停止する前の最初に製造した単結晶の直径以下で、予め定めた基準歩留りを満たす、前記残りの原料結晶棒を用いて再び製造できる単結晶の最大直径を決定する、又は、前記予め定めた基準歩留りを満たさない場合は、前記残りの原料結晶棒では単結晶の製造をしないことを決定する判定工程と、
前記再び製造できる単結晶の最大直径を決定した場合には、前記残りの原料結晶棒を用いて決定した前記再び製造できる単結晶の最大直径で単結晶を製造する再製造工程と
を有することを特徴とする単結晶の製造方法を提供する。 In order to solve the above problems, the present invention forms a floating zone by heating and melting a raw material crystal rod with an induction heating coil, and the raw material crystal rod on the upper side and the single crystal rod on the lower side with respect to the induction heating coil. A method for producing a single crystal by the FZ method, in which the single crystal ingot is grown by relatively lowering while rotating, and moving the floating zone,
When the growth is stopped during the crystal growth and the production of the single crystal by the FZ method is finished, a measurement step of measuring the weight of the remaining raw material crystal rods,
The theoretical yield of the single crystal straight body part excluding the cone part and the tail part with respect to the remaining raw material crystal rod of the single crystal rod that can be theoretically produced from the remaining raw material crystal rod is calculated from the measured weight, and the crystal is obtained. The diameter of the first single crystal before the growth is stopped in the middle of the growth is less than or equal to the predetermined reference yield, the maximum diameter of the single crystal that can be produced again using the remaining raw material crystal rods is determined, or If the predetermined reference yield is not satisfied, a determination step of determining not to manufacture a single crystal with the remaining raw material crystal rods,
When the maximum diameter of the re-manufacturable single crystal is determined, it has a re-manufacturing step of manufacturing a single crystal with the maximum diameter of the re-manufacturable single crystal determined using the remaining raw material crystal rods. A method for producing a characteristic single crystal is provided.
結晶成長途中で成長を停止し、ＦＺ法による単結晶の製造を終了した場合に、残りの原料結晶棒の重量を測定する測定工程と、
前記残りの原料結晶棒から理論的に製造できる単結晶棒の前記残りの原料結晶棒に対するコーン部とテール部を除いた単結晶直胴部の理論歩留りを前記測定した重量から計算し、前記結晶成長途中で成長を停止する前の最初に製造した単結晶の直径以下で、予め定めた基準歩留りを満たす、前記残りの原料結晶棒を用いて再び製造できる単結晶の最大直径を決定する、又は、前記予め定めた基準歩留りを満たさない場合は、前記残りの原料結晶棒では単結晶の製造をしないことを決定する判定工程と、
前記再び製造できる単結晶の最大直径を決定した場合には、前記残りの原料結晶棒を用いて決定した前記再び製造できる単結晶の最大直径で単結晶を製造する再製造工程と
を有することを特徴とする単結晶の製造方法を提供する。 In order to solve the above problems, the present invention forms a floating zone by heating and melting a raw material crystal rod with an induction heating coil, and the raw material crystal rod on the upper side and the single crystal rod on the lower side with respect to the induction heating coil. A method for producing a single crystal by the FZ method, in which the single crystal ingot is grown by relatively lowering while rotating, and moving the floating zone,
When the growth is stopped during the crystal growth and the production of the single crystal by the FZ method is finished, a measurement step of measuring the weight of the remaining raw material crystal rods,
The theoretical yield of the single crystal straight body part excluding the cone part and the tail part with respect to the remaining raw material crystal rod of the single crystal rod that can be theoretically produced from the remaining raw material crystal rod is calculated from the measured weight, and the crystal is obtained. The diameter of the first single crystal before the growth is stopped in the middle of the growth is less than or equal to the predetermined reference yield, the maximum diameter of the single crystal that can be produced again using the remaining raw material crystal rods is determined, or If the predetermined reference yield is not satisfied, a determination step of determining not to manufacture a single crystal with the remaining raw material crystal rods,
When the maximum diameter of the re-manufacturable single crystal is determined, it has a re-manufacturing step of manufacturing a single crystal with the maximum diameter of the re-manufacturable single crystal determined using the remaining raw material crystal rods. A method for producing a characteristic single crystal is provided.
このように、残りの原料結晶棒の重量を測定し、その重量の原料結晶棒から、最初に製造した単結晶の直径以下で、基準歩留りを満たす最大直径の単結晶を製造することで、適切な直径の単結晶を製造することが可能となるため、原料結晶棒を有効に利用することができ、従来よりも製品歩留りを向上させることができる。また、予め定めた基準歩留りを満たさない場合は単結晶の製造をしないことで従来よりも製造コストを低減することができる。
In this way, by measuring the weight of the remaining raw material crystal rods, from the raw material crystal rods of that weight, the diameter of the single crystal that was initially produced or less, by producing a single crystal of the maximum diameter that satisfies the reference yield, appropriate Since it becomes possible to manufacture single crystals of various diameters, the raw material crystal ingot can be effectively used, and the product yield can be improved more than ever before. Further, when the predetermined reference yield is not satisfied, the manufacturing cost can be reduced as compared with the conventional case by not manufacturing the single crystal.
このとき、前記判定工程において、
製造可能な単結晶の直径、及び、基準歩留りとして該製造可能な単結晶の直径毎の最低歩留りを予め定め、
前記残りの原料結晶棒から製造できる、前記最初に製造した単結晶の直径の理論歩留りを計算する最初の計算処理を行い、
該最初に製造した単結晶の直径の理論歩留りが直径毎に定める前記最低歩留り以上の場合は、同じ直径を前記再び製造できる単結晶の最大直径とし、直径毎に定める前記最低歩留りより小さい場合は、単結晶の仮の最大直径を、予め定めた前記製造可能な単結晶の直径のうち１サイズ小さい直径とする最初の判定処理を行い、
再度、前記残りの原料結晶棒から製造できる、前記単結晶の仮の最大直径の理論歩留りを計算する計算処理を行い、
前記単結晶の仮の最大直径の理論歩留りが直径毎に定める前記最低歩留り以上の場合は、該直径を前記再び製造できる単結晶の最大直径とし、直径毎に定める前記最低歩留りより小さい場合は、前記単結晶の仮の最大直径を予め定めた前記製造可能な単結晶の直径のうち更に１サイズ小さい直径に設定し直す判定処理を行い、該設定し直した単結晶の仮の最大直径で前記計算処理、前記判定処理を行うことを繰り返し、予め定めた前記製造可能な単結晶の直径の最低直径において計算した理論歩留りが直径毎に定める前記最低歩留りより小さい場合には単結晶を製造しないと決定することが好ましい。 At this time, in the determination step,
The diameter of the manufacturable single crystal, and the minimum yield for each diameter of the manufacturable single crystal as the reference yield is predetermined,
Can be manufactured from the remaining raw material crystal rods, perform the first calculation process to calculate the theoretical yield of the diameter of the first manufactured single crystal,
If the theoretical yield of the diameter of the initially produced single crystal is greater than or equal to the minimum yield determined for each diameter, the same diameter is used as the maximum diameter of the single crystal that can be produced again, and if it is less than the minimum yield determined for each diameter. , Performing a first determination process of setting a provisional maximum diameter of the single crystal to be one size smaller than the predetermined diameter of the manufacturable single crystal,
Again, it can be produced from the remaining raw material crystal rods, perform a calculation process to calculate the theoretical yield of the temporary maximum diameter of the single crystal,
If the theoretical yield of the provisional maximum diameter of the single crystal is equal to or more than the minimum yield determined for each diameter, the diameter is the maximum diameter of the single crystal that can be manufactured again, and if the minimum yield is less than the minimum yield determined for each diameter, A determination process is performed to reset the provisional maximum diameter of the single crystal to a diameter smaller by one size among the predetermined diameters of the manufacturable single crystals, and the provisional maximum diameter of the reset single crystal is used. Repeating the calculation process and the determination process, if the theoretical yield calculated at the predetermined minimum diameter of the diameter of the manufacturable single crystal is smaller than the minimum yield determined for each diameter, the single crystal should not be manufactured. It is preferable to determine.
製造可能な単結晶の直径、及び、基準歩留りとして該製造可能な単結晶の直径毎の最低歩留りを予め定め、
前記残りの原料結晶棒から製造できる、前記最初に製造した単結晶の直径の理論歩留りを計算する最初の計算処理を行い、
該最初に製造した単結晶の直径の理論歩留りが直径毎に定める前記最低歩留り以上の場合は、同じ直径を前記再び製造できる単結晶の最大直径とし、直径毎に定める前記最低歩留りより小さい場合は、単結晶の仮の最大直径を、予め定めた前記製造可能な単結晶の直径のうち１サイズ小さい直径とする最初の判定処理を行い、
再度、前記残りの原料結晶棒から製造できる、前記単結晶の仮の最大直径の理論歩留りを計算する計算処理を行い、
前記単結晶の仮の最大直径の理論歩留りが直径毎に定める前記最低歩留り以上の場合は、該直径を前記再び製造できる単結晶の最大直径とし、直径毎に定める前記最低歩留りより小さい場合は、前記単結晶の仮の最大直径を予め定めた前記製造可能な単結晶の直径のうち更に１サイズ小さい直径に設定し直す判定処理を行い、該設定し直した単結晶の仮の最大直径で前記計算処理、前記判定処理を行うことを繰り返し、予め定めた前記製造可能な単結晶の直径の最低直径において計算した理論歩留りが直径毎に定める前記最低歩留りより小さい場合には単結晶を製造しないと決定することが好ましい。 At this time, in the determination step,
The diameter of the manufacturable single crystal, and the minimum yield for each diameter of the manufacturable single crystal as the reference yield is predetermined,
Can be manufactured from the remaining raw material crystal rods, perform the first calculation process to calculate the theoretical yield of the diameter of the first manufactured single crystal,
If the theoretical yield of the diameter of the initially produced single crystal is greater than or equal to the minimum yield determined for each diameter, the same diameter is used as the maximum diameter of the single crystal that can be produced again, and if it is less than the minimum yield determined for each diameter. , Performing a first determination process of setting a provisional maximum diameter of the single crystal to be one size smaller than the predetermined diameter of the manufacturable single crystal,
Again, it can be produced from the remaining raw material crystal rods, perform a calculation process to calculate the theoretical yield of the temporary maximum diameter of the single crystal,
If the theoretical yield of the provisional maximum diameter of the single crystal is equal to or more than the minimum yield determined for each diameter, the diameter is the maximum diameter of the single crystal that can be manufactured again, and if the minimum yield is less than the minimum yield determined for each diameter, A determination process is performed to reset the provisional maximum diameter of the single crystal to a diameter smaller by one size among the predetermined diameters of the manufacturable single crystals, and the provisional maximum diameter of the reset single crystal is used. Repeating the calculation process and the determination process, if the theoretical yield calculated at the predetermined minimum diameter of the diameter of the manufacturable single crystal is smaller than the minimum yield determined for each diameter, the single crystal should not be manufactured. It is preferable to determine.
このような方法を用いれば、より簡単で確実に、従来よりも製品歩留りを向上させることができ、また、製造コストを低減することができる。
By using such a method, the product yield can be improved more easily and reliably than before, and the manufacturing cost can be reduced.
本発明の単結晶の製造方法によると、残りの原料結晶棒の重量を測定し、その重量の原料結晶棒から、最初に製造した単結晶の直径以下で、基準歩留りを満たす最大直径の単結晶を製造することで、適切な直径の単結晶を製造することが可能となるため、原料結晶棒を有効に利用することができ、従来よりも製品歩留りを向上させることができる。また、予め定めた基準歩留りを満たさない場合は単結晶の製造をしないことで従来よりも製造コストを低減することができる。
According to the method for producing a single crystal of the present invention, the weight of the remaining raw material crystal rod is measured, and from the raw material crystal rod of that weight, the diameter of the first produced single crystal or less, the maximum diameter of the single crystal satisfying the reference yield Since it becomes possible to manufacture a single crystal having an appropriate diameter, it is possible to effectively use the raw material crystal ingot, and it is possible to improve the product yield more than ever before. Further, when the predetermined reference yield is not satisfied, the manufacturing cost can be reduced as compared with the conventional case by not manufacturing the single crystal.
上述したように、途中で結晶成長を停止させた場合に、残りのシリコン原料結晶棒から製品を再製造すると、製品部分に対して製品にならないコーン部やテール部の比率が高くなり必然的に歩留りは低下してしまうという課題があった。
As described above, if the product is remanufactured from the remaining silicon raw material crystal rods when the crystal growth is stopped on the way, the ratio of the cone part and the tail part which are not the product to the product part is inevitably high. There is a problem that the yield is reduced.
本発明者らは、このような課題を解決すべく鋭意検討を重ねた結果、途中で結晶成長を停止させた場合に、残りの原料結晶棒を有効に利用することで歩留り低下を抑制できることが判り、本発明を完成させた。
As a result of intensive studies to solve such a problem, the inventors of the present invention can suppress the yield reduction by effectively utilizing the remaining raw material crystal rods when the crystal growth is stopped midway. Understood, the present invention was completed.
即ち、本発明は、原料結晶棒を誘導加熱コイルで加熱溶融して浮遊帯域を形成し、前記誘導加熱コイルに対して上側の前記原料結晶棒及び下側の単結晶棒を回転させながら相対的に下降させ、前記浮遊帯域を移動させることで前記単結晶棒を育成するＦＺ法による単結晶の製造方法であって、結晶成長途中で成長を停止し、ＦＺ法による単結晶の製造を終了した場合に、残りの原料結晶棒の重量を測定する測定工程と、前記残りの原料結晶棒から理論的に製造できる単結晶棒の前記残りの原料結晶棒に対するコーン部とテール部を除いた単結晶直胴部の理論歩留りを前記測定した重量から計算し、前記結晶成長途中で成長を停止する前の最初に製造した単結晶の直径以下で、予め定めた基準歩留りを満たす、前記残りの原料結晶棒を用いて再び製造できる単結晶の最大直径を決定する、又は、前記予め定めた基準歩留りを満たさない場合は、前記残りの原料結晶棒では単結晶の製造をしないことを決定する判定工程と、前記再び製造できる単結晶の最大直径を決定した場合には、前記残りの原料結晶棒を用いて決定した前記再び製造できる単結晶の最大直径で単結晶を製造する再製造工程とを有することを特徴とする単結晶の製造方法である。
That is, according to the present invention, a raw material crystal rod is heated and melted by an induction heating coil to form a floating zone, and the upper raw material crystal rod and the lower single crystal rod are relatively rotated with respect to the induction heating coil. In the method for producing a single crystal by the FZ method, in which the single crystal ingot is grown by moving the floating zone to a low temperature, the growth is stopped during the crystal growth, and the production of the single crystal by the FZ method is completed. In this case, a measuring step of measuring the weight of the remaining raw material crystal rods, and a single crystal excluding the cone portion and tail portion of the remaining raw material crystal rods of the single crystal rod that can be theoretically produced from the remaining raw material crystal rods. The theoretical yield of the straight body is calculated from the measured weight, the diameter of the first single crystal before the growth is stopped before the growth is stopped during the crystal growth, and the predetermined standard yield is satisfied, the remaining raw material crystals. To determine the maximum diameter of a single crystal that can be manufactured again using a rod, or if the predetermined reference yield is not satisfied, a determination step to determine that the remaining raw material crystal rod does not produce a single crystal. When the maximum diameter of the re-manufacturable single crystal is determined, a remanufacturing step of manufacturing a single crystal with the maximum diameter of the re-manufacturable single crystal determined using the remaining raw material crystal rods is included. And a method for producing a single crystal.
このように、残りの原料結晶棒の重量に適した、基準歩留りを満たす最大直径の単結晶を製造することで、従来よりも製品歩留りを向上させることができる。また、予め定めた基準歩留りを満たさない場合は単結晶の製造をしないことで従来よりも製造コストを低減することができる。
In this way, by producing a single crystal with the maximum diameter that meets the standard yield and is suitable for the weight of the remaining raw material crystal rods, it is possible to improve the product yield more than before. Further, when the predetermined reference yield is not satisfied, the manufacturing cost can be reduced as compared with the conventional case by not manufacturing the single crystal.
以下、図を参照しながら本発明について実施の形態を説明するが、本発明はこれに限定されるものではない。
Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.
例として図１の本発明のシリコン原料結晶棒の再利用のフローを用いて、本発明の単結晶の製造方法を説明する。
As an example, the method for producing the single crystal of the present invention will be described using the flow of reusing the silicon raw material crystal rod of the present invention of FIG.
まず、本発明の単結晶の製造方法の判定工程における判定基準を作成することができる。ここでは、例えば、図１に示すようなシリコン原料結晶棒の再利用のフローにおいて用いる判定基準を作成することができる。このとき、結晶成長途中で成長を停止する前の最初に製造した単結晶の直径以下で、製造可能な単結晶の直径、及び、基準歩留りとして製造可能な単結晶の直径毎の最低歩留りを予め定めておく（図１のＡ）。
First, it is possible to create a judgment standard in the judgment step of the method for producing a single crystal of the present invention. Here, for example, a criterion used in the flow of reusing a silicon source crystal ingot as shown in FIG. 1 can be created. At this time, the diameter of the single crystal that can be manufactured first before the growth is stopped in the middle of crystal growth, the diameter of the single crystal that can be manufactured, and the minimum yield for each diameter of the single crystal that can be manufactured as the reference yield are set in advance. Set (A in FIG. 1).
図１の本発明のシリコン原料結晶棒の再利用のフローでは、最初に、結晶成長途中で成長を停止した（図１のＢ）後の残りの原料結晶棒の重量から製造できる、結晶成長途中で成長を停止する前の最初に製造した単結晶直径の理論歩留りを計算する最初の計算処理を行い（図１のＤ）、その理論歩留りが予め直径毎に定めた最低歩留り以上の場合は同じ単結晶の直径を再び製造できる単結晶の最大直径に決定し（図１のＦ）、最低歩留りより小さい場合は単結晶の仮の最大直径を予め定めた製造可能な単結晶の直径のうち１サイズ小さい直径とする最初の判定処理を行う（図１のＨ）。
In the flow of reusing the silicon raw material crystal rod of the present invention of FIG. 1, first, during the crystal growth, which can be manufactured from the weight of the remaining raw material crystal rod after the growth is stopped during the crystal growth (B of FIG. 1). The first calculation process is performed to calculate the theoretical yield of the diameter of the first single crystal produced before the growth was stopped at (D in FIG. 1). If the theoretical yield is equal to or higher than the minimum yield preset for each diameter, it is the same. The diameter of the single crystal is determined to be the maximum diameter of the single crystal that can be produced again (F in FIG. 1). The first determination process for making the diameter smaller is performed (H in FIG. 1).
そして、上記理論歩留りが最低歩留りより小さい場合は、再度、単結晶の仮の最大直径の理論歩留りを計算する計算処理を行い、その理論歩留りが予め直径毎に定めた最低歩留り以上の場合は該直径を再び製造できる単結晶の最大直径とし、最低歩留りより小さい場合は単結晶の仮の最大直径を予め定めた直径のうち更に１サイズ小さい直径に設定し直す判定処理を行う（図１のＥ）。上記単結晶の仮の最大直径の理論歩留りが最低歩留りより小さい場合は、設定し直した単結晶の仮の最大直径で上記計算処理、上記判定処理を行うことを繰り返す。また、予め定めた最低直径において計算した理論歩留りが最低直径における最低歩留りより小さい場合には製品を製造しない（図１のＩ）。
Then, if the theoretical yield is smaller than the minimum yield, again, the calculation process of calculating the theoretical yield of the provisional maximum diameter of the single crystal is performed, and if the theoretical yield is more than the minimum yield previously determined for each diameter, The diameter is defined as the maximum diameter of the single crystal that can be manufactured again, and when the yield is smaller than the minimum yield, the determination processing is performed to reset the temporary maximum diameter of the single crystal to a diameter that is one size smaller than the predetermined diameter (E in FIG. 1). ). When the theoretical yield of the temporary maximum diameter of the single crystal is smaller than the minimum yield, the calculation process and the determination process are repeated with the temporary maximum diameter of the single crystal reset. If the theoretical yield calculated at the predetermined minimum diameter is smaller than the minimum yield at the minimum diameter, the product is not manufactured (I in FIG. 1).
上記のように、単結晶の理論歩留りが、直径毎に定めた最低歩留り以上であるか、直径毎に定めた最低歩留りより小さいかを判定基準にすることができる。
As described above, it is possible to determine whether the theoretical yield of a single crystal is equal to or higher than the minimum yield determined for each diameter or smaller than the minimum yield determined for each diameter.
また、ここで、理論歩留りとは、結晶成長途中で成長を停止した後の残りの原料結晶棒から理論的に製造できる単結晶棒の残りの原料結晶棒に対するコーン部とテール部を除いた単結晶直胴部の歩留りのことである。
Further, here, the theoretical yield means a single crystal rod that is theoretically manufactured from the remaining raw material crystal rods after the growth is stopped during the crystal growth, except for the cone portion and the tail portion for the remaining raw material crystal rods. It is the yield of the straight body of the crystal.
このような方法を用いれば、より簡単で確実に、従来よりも製品歩留りを向上させることができ、また、製造コストを低減することができる。
By using such a method, the product yield can be improved more easily and reliably than before, and the manufacturing cost can be reduced.
ただし、残りの原料結晶棒の重量が軽く、例えばコーン部とテール部の重量にも満たないような、明らかに最初に製造した単結晶の直径と同直径では最低歩留りに達しない場合には、最初に製造した製品の直径より小さい直径を仮に単結晶の仮の最大直径と決めて、その直径から上記計算処理、上記判定処理を開始することができる。
However, when the weight of the remaining raw material crystal rod is light, for example, the weight of the cone portion and the tail portion is less than the weight, it is apparent that the minimum yield cannot be reached at the same diameter as the diameter of the initially prepared single crystal, A diameter smaller than the diameter of the initially manufactured product can be temporarily determined as the temporary maximum diameter of the single crystal, and the calculation processing and the determination processing can be started from the diameter.
また、製造可能な単結晶の直径としては、８インチ（直径２００ｍｍ）、６インチ（直径１５０ｍｍ）、５インチ（直径１２５ｍｍ）、４インチ（直径１００ｍｍ）、３インチ（直径７５ｍｍ）、６０ｍｍ、２インチ（直径５０ｍｍ）等を選択できるが、製造する製品直径はこの限りではない。
The diameters of the single crystals that can be manufactured are 8 inches (diameter 200 mm), 6 inches (diameter 150 mm), 5 inches (diameter 125 mm), 4 inches (diameter 100 mm), 3 inches (diameter 75 mm), 60 mm, 2 Inches (diameter 50 mm) and the like can be selected, but the product diameter to be manufactured is not limited to this.
このように、予め定めた判定基準を用いて、本発明の単結晶の製造方法を図１のフローに従ってあらためて説明する。実際にＦＺ法による単結晶の製造を行う。そして、停電、地震等の理由で成長途中で成長を停止した場合に（図１のＢ）、残りのシリコン原料結晶棒の重量を測定する測定工程を行う（図１のＣ）。
In this way, the method for producing a single crystal of the present invention will be described again according to the flow of FIG. 1, using the predetermined criteria. A single crystal is actually manufactured by the FZ method. Then, when the growth is stopped during the growth due to a power outage, an earthquake or the like (B in FIG. 1), a measurement step of measuring the weight of the remaining silicon raw material crystal ingot is performed (C in FIG. 1).
次に、単結晶直胴部の理論歩留りを測定した重量から計算し、結晶成長途中で成長を停止する前の最初に製造した単結晶の直径以下で、予め定めた基準歩留りを満たす、残りの原料結晶棒を用いて再び製造できる単結晶の最大直径を決定する（図１のＤ、Ｅ、Ｆ）、又は、予め定めた基準歩留りを満たさない場合は、前記残りの原料結晶棒では単結晶の製造をしないことを決定する（図１のＤ、Ｅ、Ｈ、Ｉ）判定工程を行う。
Next, the theoretical yield of the single crystal straight body is calculated from the measured weight, and is less than or equal to the diameter of the first single crystal produced before stopping the growth in the course of crystal growth, and the predetermined reference yield is satisfied. Determine the maximum diameter of a single crystal that can be produced again using the raw material crystal rods (D, E, F in FIG. 1), or if the predetermined reference yield is not satisfied, the remaining raw material crystal rods are single crystals. Is determined (D, E, H, I in FIG. 1).
判定工程では、例えば、上記のように、まず、仮に決めた直径を単結晶の仮の最大直径として、その直径の理論歩留りを計算する計算処理を行う（図１のＤ）。そして、その直径の予め定めた最低歩留りと比較して（図１のＥ）、最低歩留り以上の場合は、その直径を再び製造できる単結晶の最大直径とし（図１のＦ）、最低歩留りより小さい場合には、その直径より１サイズ小さい直径を仮の最大直径に設定し直す判定処理を行い（図１のＨ）、再び理論歩留りを計算して上記と同様の比較を行う。このように計算処理と判定処理を繰り返して、製造可能な単結晶の直径の最低直径でも最低歩留りに達しない場合には、残りの原料結晶棒を用いた単結晶の製造は行わないと決定することができる（図１のＩ）。
In the determination step, for example, as described above, first, the temporarily determined diameter is used as the temporary maximum diameter of the single crystal, and the theoretical yield of the diameter is calculated (D in FIG. 1). Then, in comparison with the predetermined minimum yield of the diameter (E in FIG. 1), if the yield is more than the minimum yield, the diameter is set as the maximum diameter of the single crystal that can be manufactured again (F in FIG. 1), and the minimum yield is calculated. If it is smaller, a determination process for resetting the diameter one size smaller than the diameter to the temporary maximum diameter is performed (H in FIG. 1), the theoretical yield is calculated again, and the same comparison as above is performed. By repeating the calculation process and the determination process in this way, if the minimum yield of the single crystal diameter that can be manufactured does not reach the minimum yield, it is determined that the single crystal is not manufactured using the remaining raw material crystal rods. It is possible (I in FIG. 1).
判定工程において、再び製造できる単結晶の最大直径を決定した場合には、残りの原料結晶棒を用いて、決定した再び製造できる単結晶の最大直径で単結晶を製造する再製造工程を行う（図１のＧ）。
In the determination step, when the maximum diameter of the re-manufacturable single crystal is determined, the re-manufacturing step of manufacturing the single crystal with the determined maximum diameter of the re-manufacturable single crystal is performed using the remaining raw material crystal rods ( G in FIG. 1).
残りの原料結晶棒を用いて単結晶の再製造工程を行う方法は、一般的なＦＺ法による単結晶の製造方法を用いることができる。
As a method of performing a single crystal remanufacturing process using the remaining raw material crystal rods, a general FZ method single crystal manufacturing method can be used.
ＦＺ法では、単結晶棒を所望の直径まで拡げながら成長させるコーン工程、コーン形成後、単結晶棒を一定直径に制御して成長させる直胴工程を経て、単結晶製造が行われる。再製造工程では、コーン工程において、単結晶の直径を、上記判定工程において決定した再び製造できる単結晶の最大直径まで拡げ、この直径の単結晶を成長させる。
In the FZ method, a single crystal is manufactured through a cone process of growing a single crystal rod while expanding it to a desired diameter, and a straight body process of growing the single crystal rod while controlling the diameter of the single crystal rod to a constant diameter after the cone is formed. In the remanufacturing step, in the cone step, the diameter of the single crystal is expanded to the maximum diameter of the single crystal that can be remanufactured, which has been determined in the determination step, and the single crystal having this diameter is grown.
以下、本発明の実施例及び比較例を示して本発明をより具体的に説明するが、本発明はこれらに限定されるものではない。
Hereinafter, the present invention will be described more specifically by showing Examples and Comparative Examples of the present invention, but the present invention is not limited to these.
（実施例）
判定基準を、単結晶の理論歩留りが、以下の直径毎に定めた最低歩留り以上であるか、直径毎に定めた最低歩留りより小さいかとして、ＦＺ法による８インチ（２００ｍｍ）の直径の単結晶の製造を行なった。成長途中で成長を停止した場合に、図１のようなフローで、残りの原料結晶棒を用いて、基準歩留りとして以下の直径毎に定めた最低歩留りを満たす最大直径の単結晶の再製造を行った。また、実施例の判定工程において、単結晶の製造をしないと決定することはなかった。
＜判定基準＞
直径 最低歩留り
８インチ ４０％
６インチ ４０％
４インチ ４０％
３インチ ４０％
６０ｍｍ ４０％
２インチ ４０％ (Example)
A single crystal having a diameter of 8 inches (200 mm) according to the FZ method is determined based on whether the theoretical yield of the single crystal is equal to or higher than the minimum yield determined for each diameter below or smaller than the minimum yield determined for each diameter. Was manufactured. When the growth is stopped during the growth, the remaining raw material crystal rods are used to remanufacture the single crystal having the maximum diameter satisfying the minimum yield defined for each of the following diameters as the reference yield by the flow as shown in FIG. went. Moreover, in the determination step of the example, it was not determined that the single crystal was not produced.
<Judgment criteria>
Diameter minimum yield 8 inches 40%
6 inches 40%
4 inches 40%
3 inches 40%
60 mm 40%
2 inches 40%
判定基準を、単結晶の理論歩留りが、以下の直径毎に定めた最低歩留り以上であるか、直径毎に定めた最低歩留りより小さいかとして、ＦＺ法による８インチ（２００ｍｍ）の直径の単結晶の製造を行なった。成長途中で成長を停止した場合に、図１のようなフローで、残りの原料結晶棒を用いて、基準歩留りとして以下の直径毎に定めた最低歩留りを満たす最大直径の単結晶の再製造を行った。また、実施例の判定工程において、単結晶の製造をしないと決定することはなかった。
＜判定基準＞
直径 最低歩留り
８インチ ４０％
６インチ ４０％
４インチ ４０％
３インチ ４０％
６０ｍｍ ４０％
２インチ ４０％ (Example)
A single crystal having a diameter of 8 inches (200 mm) according to the FZ method is determined based on whether the theoretical yield of the single crystal is equal to or higher than the minimum yield determined for each diameter below or smaller than the minimum yield determined for each diameter. Was manufactured. When the growth is stopped during the growth, the remaining raw material crystal rods are used to remanufacture the single crystal having the maximum diameter satisfying the minimum yield defined for each of the following diameters as the reference yield by the flow as shown in FIG. went. Moreover, in the determination step of the example, it was not determined that the single crystal was not produced.
<Judgment criteria>
Diameter minimum yield 8 inches 40%
6 inches 40%
4 inches 40%
3 inches 40%
60 mm 40%
2 inches 40%
合計３０回の成長途中で成長を停止した場合について、図１のようなフローで単結晶の再製造を行った。その結果、成長途中で成長を停止した３０本の製品歩留りは後述する比較例に比べて１０％向上した。
When the growth was stopped during the growth of 30 times in total, the single crystal was remanufactured according to the flow shown in FIG. As a result, the yield of 30 products whose growth was stopped during the growth was improved by 10% as compared with the comparative example described later.
（比較例）
成長途中で成長を停止した場合に、従来の図２のようなフローで残りの原料結晶棒を用いて単結晶の再製造を行った。その結果、成長途中で成長を停止した３０本の製品歩留りは実施例に比べて１０％低かった。 (Comparative example)
When the growth was stopped during the growth, a single crystal was remanufactured by using the remaining raw material crystal rod in the conventional flow as shown in FIG. As a result, the yield of 30 products whose growth was stopped during the growth was 10% lower than that of the example.
成長途中で成長を停止した場合に、従来の図２のようなフローで残りの原料結晶棒を用いて単結晶の再製造を行った。その結果、成長途中で成長を停止した３０本の製品歩留りは実施例に比べて１０％低かった。 (Comparative example)
When the growth was stopped during the growth, a single crystal was remanufactured by using the remaining raw material crystal rod in the conventional flow as shown in FIG. As a result, the yield of 30 products whose growth was stopped during the growth was 10% lower than that of the example.
このように、実施例は比較例よりも製品歩留りが高く、本発明の単結晶の製造方法を用いることで、結晶成長途中で成長を停止し、ＦＺ法による単結晶の製造を終了した場合に、残りの原料結晶棒を有効に利用することができ、従来よりも製品歩留りを向上させることができた。また、残りの原料結晶棒から出来るだけ大きな重量の単結晶を製造することで、製造コストを低減することができた。
As described above, the product yield of the example is higher than that of the comparative example, and by using the method for producing a single crystal of the present invention, when the growth is stopped during the crystal growth and the production of the single crystal by the FZ method is completed, The remaining raw material crystal rods can be effectively used, and the product yield can be improved more than ever before. In addition, the manufacturing cost could be reduced by manufacturing a single crystal having the largest possible weight from the remaining raw material crystal rods.
なお、本発明は、上記実施形態に限定されるものではない。上記実施形態は、例示であり、本発明の特許請求の範囲に記載された技術的思想と実質的に同一な構成を有し、同様な作用効果を奏するものは、いかなるものであっても本発明の技術的範囲に包含される。
The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, has substantially the same configuration as the technical idea described in the scope of the claims of the present invention, and has the same operational effect It is included in the technical scope of the invention.
Claims (2)
- 原料結晶棒を誘導加熱コイルで加熱溶融して浮遊帯域を形成し、前記誘導加熱コイルに対して上側の前記原料結晶棒及び下側の単結晶棒を回転させながら相対的に下降させ、前記浮遊帯域を移動させることで前記単結晶棒を育成するＦＺ法による単結晶の製造方法であって、
結晶成長途中で成長を停止し、ＦＺ法による単結晶の製造を終了した場合に、残りの原料結晶棒の重量を測定する測定工程と、
前記残りの原料結晶棒から理論的に製造できる単結晶棒の前記残りの原料結晶棒に対するコーン部とテール部を除いた単結晶直胴部の理論歩留りを前記測定した重量から計算し、前記結晶成長途中で成長を停止する前の最初に製造した単結晶の直径以下で、予め定めた基準歩留りを満たす、前記残りの原料結晶棒を用いて再び製造できる単結晶の最大直径を決定する、又は、前記予め定めた基準歩留りを満たさない場合は、前記残りの原料結晶棒では単結晶の製造をしないことを決定する判定工程と、
前記再び製造できる単結晶の最大直径を決定した場合には、前記残りの原料結晶棒を用いて決定した前記再び製造できる単結晶の最大直径で単結晶を製造する再製造工程と
を有することを特徴とする単結晶の製造方法。 The raw material crystal rod is heated and melted by an induction heating coil to form a floating zone, and the raw material crystal rod on the upper side and the single crystal rod on the lower side are relatively lowered with respect to the induction heating coil to lower the floating crystal. A method for producing a single crystal by the FZ method, wherein the single crystal ingot is grown by moving a zone,
When the growth is stopped during the crystal growth and the production of the single crystal by the FZ method is finished, a measurement step of measuring the weight of the remaining raw material crystal rods,
The theoretical yield of the single crystal straight body part excluding the cone part and the tail part with respect to the remaining raw material crystal rod of the single crystal rod that can be theoretically produced from the remaining raw material crystal rod is calculated from the measured weight, and the crystal is obtained. The diameter of the first single crystal before the growth is stopped in the middle of the growth is less than or equal to the predetermined reference yield, the maximum diameter of the single crystal that can be produced again using the remaining raw material crystal rods is determined, or If the predetermined reference yield is not satisfied, a determination step of determining not to manufacture a single crystal with the remaining raw material crystal rods,
When the maximum diameter of the re-manufacturable single crystal is determined, it has a re-manufacturing step of manufacturing a single crystal with the maximum diameter of the re-manufacturable single crystal determined using the remaining raw material crystal rods. A method for producing a characteristic single crystal. - 前記判定工程において、
製造可能な単結晶の直径、及び、基準歩留りとして該製造可能な単結晶の直径毎の最低歩留りを予め定め、
前記残りの原料結晶棒から製造できる、前記最初に製造した単結晶の直径の理論歩留りを計算する最初の計算処理を行い、
該最初に製造した単結晶の直径の理論歩留りが直径毎に定める前記最低歩留り以上の場合は、同じ直径を前記再び製造できる単結晶の最大直径とし、直径毎に定める前記最低歩留りより小さい場合は、単結晶の仮の最大直径を、予め定めた前記製造可能な単結晶の直径のうち１サイズ小さい直径とする最初の判定処理を行い、
再度、前記残りの原料結晶棒から製造できる、前記単結晶の仮の最大直径の理論歩留りを計算する計算処理を行い、
前記単結晶の仮の最大直径の理論歩留りが直径毎に定める前記最低歩留り以上の場合は、該直径を前記再び製造できる単結晶の最大直径とし、直径毎に定める前記最低歩留りより小さい場合は、前記単結晶の仮の最大直径を予め定めた前記製造可能な単結晶の直径のうち更に１サイズ小さい直径に設定し直す判定処理を行い、該設定し直した単結晶の仮の最大直径で前記計算処理、前記判定処理を行うことを繰り返し、予め定めた前記製造可能な単結晶の直径の最低直径において計算した理論歩留りが直径毎に定める前記最低歩留りより小さい場合には単結晶を製造しないと決定することを特徴とする請求項１に記載の単結晶の製造方法。 In the determination step,
The diameter of the manufacturable single crystal, and the minimum yield for each diameter of the manufacturable single crystal as the reference yield is predetermined,
Can be manufactured from the remaining raw material crystal rods, perform the first calculation process to calculate the theoretical yield of the diameter of the first manufactured single crystal,
If the theoretical yield of the diameter of the initially produced single crystal is equal to or higher than the minimum yield determined for each diameter, the same diameter is used as the maximum diameter of the single crystal that can be produced again, and if it is smaller than the minimum yield determined for each diameter. , Performing a first determination process of setting a provisional maximum diameter of the single crystal to be one size smaller than the predetermined diameter of the manufacturable single crystal,
Again, it can be produced from the remaining raw material crystal rods, perform a calculation process to calculate the theoretical yield of the temporary maximum diameter of the single crystal,
If the theoretical yield of the provisional maximum diameter of the single crystal is equal to or more than the minimum yield determined for each diameter, the diameter is the maximum diameter of the single crystal that can be manufactured again, and if the minimum yield is less than the minimum yield determined for each diameter, A determination process is performed to reset the provisional maximum diameter of the single crystal to a diameter smaller by one size among the predetermined diameters of the manufacturable single crystals, and the provisional maximum diameter of the reset single crystal is used. Repeating the calculation process and the determination process, if the theoretical yield calculated at the predetermined minimum diameter of the diameter of the manufacturable single crystal is smaller than the minimum yield determined for each diameter, the single crystal should not be manufactured. The method for producing a single crystal according to claim 1, which is determined.
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/JP2019/040814 WO2020100512A1 (en) | 2018-11-13 | 2019-10-17 | Method for producing single crystal |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP6996477B2 (en) |
| CN (1) | CN112996954B (en) |
| DE (1) | DE112019005137B4 (en) |
| WO (1) | WO2020100512A1 (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07206573A (en) * | 1994-01-17 | 1995-08-08 | Komatsu Electron Metals Co Ltd | Method for controlling formed crystal diameter in method for floating-zone melting |
| JPH11278981A (en) * | 1998-03-26 | 1999-10-12 | Shin Etsu Handotai Co Ltd | Monitoring of semiconductor single crystal production by fz process |
| JP2017193461A (en) * | 2016-04-20 | 2017-10-26 | 株式会社Sumco | Production method and device of single crystal |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5880415B2 (en) * | 2012-12-06 | 2016-03-09 | 信越半導体株式会社 | Single crystal manufacturing method |
| JP6064675B2 (en) * | 2013-02-28 | 2017-01-25 | 信越半導体株式会社 | Manufacturing method of semiconductor single crystal rod |
| JP6318938B2 (en) * | 2014-07-17 | 2018-05-09 | 株式会社Sumco | Single crystal manufacturing method and manufacturing apparatus |
| JP6332063B2 (en) | 2015-02-04 | 2018-05-30 | 信越半導体株式会社 | Semiconductor single crystal manufacturing apparatus and semiconductor single crystal manufacturing method |
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2018
- 2018-11-13 JP JP2018212846A patent/JP6996477B2/en active Active
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2019
- 2019-10-17 CN CN201980072061.XA patent/CN112996954B/en active Active
- 2019-10-17 WO PCT/JP2019/040814 patent/WO2020100512A1/en active Application Filing
- 2019-10-17 DE DE112019005137.7T patent/DE112019005137B4/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07206573A (en) * | 1994-01-17 | 1995-08-08 | Komatsu Electron Metals Co Ltd | Method for controlling formed crystal diameter in method for floating-zone melting |
| JPH11278981A (en) * | 1998-03-26 | 1999-10-12 | Shin Etsu Handotai Co Ltd | Monitoring of semiconductor single crystal production by fz process |
| JP2017193461A (en) * | 2016-04-20 | 2017-10-26 | 株式会社Sumco | Production method and device of single crystal |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2020079181A (en) | 2020-05-28 |
| DE112019005137B4 (en) | 2024-09-05 |
| DE112019005137T5 (en) | 2021-07-01 |
| JP6996477B2 (en) | 2022-01-17 |
| CN112996954B (en) | 2023-09-01 |
| CN112996954A (en) | 2021-06-18 |
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