JP2688137B2 - Method of pulling silicon single crystal - Google Patents
Method of pulling silicon single crystalInfo
- Publication number
- JP2688137B2 JP2688137B2 JP34892691A JP34892691A JP2688137B2 JP 2688137 B2 JP2688137 B2 JP 2688137B2 JP 34892691 A JP34892691 A JP 34892691A JP 34892691 A JP34892691 A JP 34892691A JP 2688137 B2 JP2688137 B2 JP 2688137B2
- Authority
- JP
- Japan
- Prior art keywords
- crystal
- single crystal
- silicon single
- rotation speed
- rpm
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
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- Liquid Deposition Of Substances Of Which Semiconductor Devices Are Composed (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、シリコン単結晶の引上
げ方法に関するもので、詳しくは、チョクラルスキー法
によるシリコン単結晶の引上げ方法に係るものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for pulling a silicon single crystal, and more particularly to a method for pulling a silicon single crystal by the Czochralski method.
【０００２】[0002]
【従来の技術】半導体装置の製造に用いられるシリコン
単結晶は主にチョクラルスキー法（ＣＺ法）によって製
造されているが、この中に、磁場印加チョクラルスキー
法（ＭＣＺ法）と呼ばれる方法がある。2. Description of the Related Art A silicon single crystal used for manufacturing a semiconductor device is mainly manufactured by the Czochralski method (CZ method). Among them, a method called a magnetic field application Czochralski method (MCZ method) is used. There is.
【０００３】このＭＣＺ法は、石英るつぼと結晶とを相
対回転させるとともに、磁場を印加することにより、シ
リコン単結晶を引き上げる方法であるが、通常、石英る
つぼの回転速度は０．１〜１０ｒｐｍ、結晶回転速度は
１０〜３０ｒｐｍに維持されている。This MCZ method is a method of pulling a silicon single crystal by applying a magnetic field while rotating the quartz crucible and the crystal relative to each other. Usually, the rotation speed of the quartz crucible is 0.1 to 10 rpm, The crystal rotation speed is maintained at 10 to 30 rpm.
【０００４】[0004]
【発明が解決しようとする課題】この方法は、通常のＣ
Ｚ法に比較して、結晶中の酸素濃度の制御性が良く、超
低酸素濃度のシリコン単結晶を製造できるという利点が
あるが、その利点があるのは５インチ未満のシリコン単
結晶の引上げに限られていた。酸素濃度に関し具体的な
数値をあげれば、５インチ未満のシリコン単結晶の場合
には、下限で１×１０17（原子／ｃｍ3）程度の酸素濃
度のシリコン単結晶を実現できるのに対し、５インチ以
上のものでは下限で５×１０17（原子／ｃｍ3）程度の
酸素濃度のものしか実現できなかった。また、下限で５
×１０17（原子／ｃｍ3）程度の酸素濃度のものが得ら
れるとは言っても、均一性をもった状態で得られた訳で
はなかった。したがって、近年のシリコンウェーハの大
口径化（６インチウェーハ、８インチウェーハ）に適応
できないこととなってきた。This method is based on the conventional C
Compared with the Z method, the controllability of the oxygen concentration in the crystal is better, and there is the advantage that an ultra-low oxygen concentration silicon single crystal can be manufactured, but the advantage is that the pulling of a silicon single crystal of less than 5 inches is possible. Was limited to. In the case of a silicon single crystal having a size of less than 5 inches, a silicon single crystal having an oxygen concentration of about 1 × 10 17 (atoms / cm 3 ) can be realized as a lower limit in the case of a specific value for the oxygen concentration. With a diameter of 5 inches or more, only a lower limit of about 5 × 10 17 (atoms / cm 3 ) was realized. Also, the lower limit is 5
Even though it was possible to obtain an oxygen concentration of approximately 10 17 (atoms / cm 3 ), it was not necessarily obtained in a uniform state. Therefore, it has become impossible to adapt to the recent increase in the diameter of silicon wafers (6 inch wafers and 8 inch wafers).
【０００５】この原因としては結晶引上げ機の大型化が
考えられる。具体的には、溶融シリコンの容器である石
英るつぼのサイズ（ちなみに従来は直径１６インチ）が
大型化し、溶融シリコンと石英るつぼとの接触面積が増
加したとともに、引上げ炉内の大型化に伴い結晶引上げ
中に加熱ヒータに供給される電力が増大し石英るつぼ壁
面の温度が上昇したことにより、石英の溶解量が増し、
溶融シリコン中の酸素濃度が増加したことが原因と考え
られる。As a cause of this, it is considered that the crystal pulling machine is upsized. Specifically, the size of the quartz crucible, which is a container of molten silicon (by comparison, 16 inches in diameter in the past) was increased, the contact area between the molten silicon and the quartz crucible was increased, and the size of the crystal inside the pulling furnace increased. The electric power supplied to the heater during pulling increased and the temperature of the wall surface of the quartz crucible rose, which increased the melting amount of quartz,
This is probably because the oxygen concentration in the molten silicon increased.
【０００６】本発明は、かかる問題点に鑑みなされたも
ので、１６インチを超える石英るつぼを用いて引き上げ
られるシリコン単結晶にあっても十分に酸素濃度の低減
が図れる方法を提供することを目的としている。本願発
明は、酸素低減と同時に結晶成長方向の酸素濃度の均一
をも目的としている。The present invention has been made in view of the above problems, and an object thereof is to provide a method capable of sufficiently reducing the oxygen concentration even in a silicon single crystal pulled by using a quartz crucible having a size of more than 16 inches. I am trying. The present invention aims at reducing oxygen and at the same time making the oxygen concentration uniform in the crystal growth direction.
【０００７】[0007]
【課題を解決するための手段】本発明のシリコン単結晶
の引上げ方法は、シリコン単結晶をチョクラルスキー法
によって引き上げるにあたり、結晶回転速度を０．２〜
１．０５ｒｐｍ、石英るつぼ回転速度を０．１〜０．６
ｒｐｍに維持するとともに、直流磁場を水平方向に印加
しつつ、酸素濃度が２〜約６×１０17（原子／ｃｍ3）
のシリコン単結晶を引き上げるようにしたものである。The method for pulling a silicon single crystal according to the present invention has a crystal rotation speed of 0.2 to 0.2 when pulling a silicon single crystal by the Czochralski method.
1.05 rpm, quartz crucible rotation speed 0.1-0.6
The oxygen concentration is 2 to about 6 × 10 17 (atoms / cm 3 ) while maintaining the rpm and applying a DC magnetic field in the horizontal direction.
The silicon single crystal is pulled up.
【０００８】[0008]
【作用】前記方法によれば、石英るつぼと結晶との相対
回転速度を低くしているので、石英るつぼからの融液シ
リコンへの酸素の溶け込みが少なくなる上、結晶回転速
度自体を遅くしているので、結晶近くの比較的低酸素濃
度の融液シリコンのみで結晶を成長させることが可能と
なる。また、直流磁場を水平方向に印加したことによ
り、熱対流が抑制される。その結果、酸素濃度の低いつ
まり２〜約６×１０17（原子／ｃｍ3）のシリコン単結
晶ひいてはシリコンウェーハの実現が図れる。According to the above method, since the relative rotation speed between the quartz crucible and the crystal is low, the dissolution of oxygen from the quartz crucible into the melted silicon is reduced, and the crystal rotation speed itself is slowed down. Therefore, it becomes possible to grow the crystal only with the melted silicon having a relatively low oxygen concentration near the crystal. Moreover, the thermal convection is suppressed by applying the DC magnetic field in the horizontal direction. As a result, it is possible to realize a silicon single crystal having a low oxygen concentration, that is, 2 to about 6 × 10 17 (atoms / cm 3 ), and thus a silicon wafer.
【０００９】なお、前記方法において、結晶回転速度を
０．２ｒｐｍ以上としたのは、０．２ｒｐｍ未満である
と、シリコン単結晶が丸く成長しないためであり、ま
た、石英るつぼ回転速度を０．１ｒｐｍ以上としたの
は、０．１ｒｐｍ未満であると、融液シリコンの撹拌が
全くなされずに、比較的低温となっている液面近傍で融
液シリコンが固化してしまう危険性があるからである。In the above method, the reason why the crystal rotation speed is set to 0.2 rpm or more is that the silicon single crystal does not grow round when the rotation speed is less than 0.2 rpm, and the quartz crucible rotation speed is set to 0. The reason why the speed is set to 1 rpm or more is that if the speed is less than 0.1 rpm, the melted silicon is not stirred at all, and there is a risk that the melted silicon solidifies near the liquid surface at a relatively low temperature. Is.
【００１０】[0010]
【実施例】以下、本発明の実施例について説明する。Embodiments of the present invention will be described below.
【００１１】シリコン原料を直径４５０ｍｍ（約１８イ
ンチ）の石英るつぼで溶融し、結晶方位＜１１１＞の種
結晶を用いて直径１３０ｍｍ（約５インチ）のシリコン
単結晶を成長させた。A silicon raw material was melted in a quartz crucible having a diameter of 450 mm (about 18 inches), and a silicon single crystal having a diameter of 130 mm (about 5 inches) was grown using a seed crystal having a crystal orientation <111>.
【００１２】その際、石英るつぼ中央での磁束密度が４
０００Ｇ（ガウス）となるような直流水平磁場を印加
し、結晶回転速度を０．５ｒｐｍ、石英るつぼの回転速
度を０．３ｒｐｍ（前記結晶回転方向とは反対の方向）
にして結晶引上げを行った。また、その際、Ａｒガスを
２００リットル／ｍｉｎの流量で流した。At this time, the magnetic flux density at the center of the quartz crucible is 4
A horizontal DC magnetic field of 000 G (gauss) was applied, the crystal rotation speed was 0.5 rpm, and the rotation speed of the quartz crucible was 0.3 rpm (direction opposite to the crystal rotation direction).
The crystal was pulled up. At that time, Ar gas was flown at a flow rate of 200 liter / min.
【００１３】そして、この引き上げられたシリコン単結
晶の酸素濃度の測定を行ったところ、図１に示す結果が
得られた。When the oxygen concentration of the pulled silicon single crystal was measured, the results shown in FIG. 1 were obtained.
【００１４】この図１からは、シリコン単結晶の肩の部
分を除けば、酸素濃度が２〜３×１０17（原子／ｃ
ｍ3）程度で均一になっているのが判る。From FIG. 1, the oxygen concentration is 2 to 3 × 10 17 (atoms / c) except for the shoulder portion of the silicon single crystal.
It can be seen that it is uniform at about m 3 ).
【００１５】このような結果が得られた理由を考える
に、従来のＭＣＺ法では、石英るつぼの回転速度が０．
１〜１０ｒｐｍ程度、結晶回転速度が１０〜３０ｒｐｍ
程度となっていることから、石英るつぼと結晶との相対
回転速度が比較的速く、その結果、石英るつぼからの酸
素の溶け込みが比較的多かったのに対して、前記実施例
の方法では、石英るつぼと結晶との相対回転速度が遅く
なっているため、石英るつぼからの酸素の溶け込みが抑
制されていることが先ず一つの理由と考えられる。Considering the reason why such a result is obtained, in the conventional MCZ method, the rotation speed of the quartz crucible is 0.
About 1 to 10 rpm, crystal rotation speed is 10 to 30 rpm
Since the relative rotation speed of the quartz crucible and the crystal is relatively high, and as a result, the dissolution of oxygen from the quartz crucible was relatively large, whereas the method of the above-mentioned embodiment was characterized by the quartz It is considered that one of the reasons is that the relative rotation speed between the crucible and the crystal is slow, so that the dissolution of oxygen from the quartz crucible is suppressed.
【００１６】また、実施例の方法では、結晶の引上げ速
度を０．５ｒｐｍにし、結晶近くの融液シリコンのみで
結晶を成長させている。その結果、結晶近くの比較的低
酸素濃度の融液シリコンのみで結晶を成長させることが
可能となり、シリコン単結晶の酸素濃度がより低減され
たものと考えられる。Further, in the method of the embodiment, the crystal pulling rate is set to 0.5 rpm and the crystal is grown only by the melted silicon near the crystal. As a result, it is considered that the crystal can be grown only with the melted silicon having a relatively low oxygen concentration near the crystal, and the oxygen concentration of the silicon single crystal is further reduced.
【００１７】さらに、直流磁場を水平方向に印加したこ
とにより、主に石英るつぼ周辺部で起こる熱対流の鉛直
方向成分と、および主にるつぼ中心部で起こる回転に伴
う強制対流とが効果的に防止されて、シリコン単結晶の
酸素濃度がより低減されかつ均一化したものと考えられ
る。なお、他の条件を同じにして磁場強度を３５００Ｇ
（ガウス）にして同様の試験を行ったところ、図２に示
すような結果が得られた。この結果から、３５００Ｇの
場合は４〜６×１０17（原子／ｃｍ3）の酸素濃度のシ
リコン単結晶が略均一的な状態で得られているのが判
る。Further, by applying the DC magnetic field in the horizontal direction, the vertical component of the thermal convection mainly occurring in the peripheral part of the quartz crucible and the forced convection accompanying the rotation mainly occurring in the central part of the crucible are effective. It is considered that the oxygen concentration of the silicon single crystal was further reduced and made uniform by preventing. The other conditions are the same and the magnetic field strength is 3500G.
When the same test was performed using (Gauss), the results shown in FIG. 2 were obtained. From this result, it is understood that in the case of 3500 G, a silicon single crystal having an oxygen concentration of 4 to 6 × 10 17 (atoms / cm 3 ) is obtained in a substantially uniform state.
【００１８】（他の試験）その後、４０００Ｇの磁場強
度にした条件で、石英るつぼ回転速度および結晶回転速
度条件を変えて試験を行ったところ、酸素濃度が２〜３
×１０17（原子／ｃｍ3）程度のシリコン単結晶が得ら
れる範囲を調べたところ、図３に示す斜線領域であるこ
とが判った。この斜線領域の結晶回転速度は、るつぼ回
転速度０．１ｒｐｍにおいて、１．０５ｒｐｍである。
また、るつぼ回転速度の最大値は０．６ｒｐｍである。(Other tests) After that, a test was conducted under the conditions of a magnetic field strength of 4000 G while changing the quartz crucible rotation speed and the crystal rotation speed conditions.
When a range in which a silicon single crystal of about 10 17 (atoms / cm 3 ) was obtained was examined, it was found to be a hatched region shown in FIG. The crystal rotation speed in the shaded area is 1.05 rpm in the crucible rotation speed of 0.1 rpm.
The maximum value of the crucible rotation speed is 0.6 rpm.
【００１９】なお、この試験結果から、石英るつぼ回転
速度を０．１ｒｐｍに向けて下げるに従って幅広い範囲
で良好な結果が得られていることが判る。つまり、石英
るつぼ回転速度よりも結晶回転速度の影響が強く現われ
ることが判る。From these test results, it is understood that good results are obtained in a wide range as the rotational speed of the quartz crucible is lowered toward 0.1 rpm. That is, it is understood that the influence of the crystal rotation speed appears more strongly than that of the quartz crucible rotation speed.
【００２０】以上の実験は実施例と同様に、直径５イン
チの単結晶引上げについて行われたが、さらに６〜８イ
ンチ等においても同様な結果が得られ、結晶回転速度お
よびるつぼ回転速度の関係は、ほぼ同一といえる。Similar to the embodiment, the above experiment was carried out for pulling a single crystal having a diameter of 5 inches, but similar results were obtained at 6 to 8 inches, and the relationship between the crystal rotation speed and the crucible rotation speed. Can be said to be almost the same.
【００２１】以上、本発明の一実施例について説明した
が、本発明は、かかる実施例に限定されるものではな
く、その要旨を逸脱しない範囲において、種々の変形が
可能であることはいうまでもない。Although one embodiment of the present invention has been described above, it is needless to say that the present invention is not limited to this embodiment and various modifications can be made without departing from the scope of the invention. Nor.
【００２２】[0022]
【発明の効果】本発明によれば、シリコン単結晶をチョ
クラルスキー法によって引き上げるにあたり、結晶回転
速度を０．２〜１．０５ｒｐｍ、石英るつぼ回転速度を
０．１〜０．６ｒｐｍに維持するとともに、直流磁場を
水平方向に印加しつつシリコン単結晶を引き上げるよう
にしたので、１６インチを超える石英るつぼを用いて引
き上げられるシリコン単結晶にあっても十分に酸素濃度
の低減が図れる。According to the present invention, when pulling a silicon single crystal by the Czochralski method, the crystal rotation speed is maintained at 0.2 to 1.05 rpm and the quartz crucible rotation speed is maintained at 0.1 to 0.6 rpm. At the same time, since the silicon single crystal is pulled while applying a DC magnetic field in the horizontal direction, it is possible to sufficiently reduce the oxygen concentration even in the silicon single crystal pulled by using the quartz crucible having a size of more than 16 inches.
【図１】試験結果の酸素濃度分布を表す図である。FIG. 1 is a diagram showing an oxygen concentration distribution of test results.
【図２】磁場強度を変えた場合の酸素濃度分布を表す図
である。FIG. 2 is a diagram showing an oxygen concentration distribution when the magnetic field strength is changed.
【図３】回転速度の最適範囲を示す図である。FIG. 3 is a diagram showing an optimum range of rotation speed.
Claims (1)
よって引き上げるにあたり、結晶回転速度を０．２〜
１．０５ｒｐｍ、石英るつぼ回転速度を０．１〜０．６
ｒｐｍに維持するとともに、直流磁場を水平方向に印加
しつつ、酸素濃度が２〜約６×１０17（原子／ｃｍ3）
のシリコン単結晶を引き上げるようにしたことを特徴と
するシリコン単結晶の引上げ方法。1. When pulling a silicon single crystal by the Czochralski method, the crystal rotation speed is 0.2 to
1.05 rpm, quartz crucible rotation speed 0.1-0.6
The oxygen concentration is 2 to about 6 × 10 17 (atoms / cm 3 ) while maintaining the rpm and applying a DC magnetic field in the horizontal direction.
1. A method for pulling a silicon single crystal, wherein the silicon single crystal is pulled.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34892691A JP2688137B2 (en) | 1991-12-04 | 1991-12-04 | Method of pulling silicon single crystal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34892691A JP2688137B2 (en) | 1991-12-04 | 1991-12-04 | Method of pulling silicon single crystal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05155682A JPH05155682A (en) | 1993-06-22 |
| JP2688137B2 true JP2688137B2 (en) | 1997-12-08 |
Family
ID=18400315
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP34892691A Expired - Fee Related JP2688137B2 (en) | 1991-12-04 | 1991-12-04 | Method of pulling silicon single crystal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2688137B2 (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH09263491A (en) * | 1996-03-27 | 1997-10-07 | Shin Etsu Handotai Co Ltd | Device for producing silicon single crystal |
| WO2001082358A1 (en) * | 2000-04-24 | 2001-11-01 | Shin-Etsu Handotai Co.,Ltd. | Production method of silicon mirror wafer |
| JP2005322712A (en) * | 2004-05-07 | 2005-11-17 | Toyota Motor Corp | Semiconductor substrate, semiconductor device, and their manufacturing method |
| JP5240191B2 (en) | 2007-05-30 | 2013-07-17 | 株式会社Ｓｕｍｃｏ | Silicon single crystal pulling device |
| DE102008062049A1 (en) | 2008-05-19 | 2009-12-03 | Covalent Materials Corp. | Manufacture of low-oxygen concentrated silicon single crystal for silicon semiconductor, involves subjecting raw material silicon to silicon single crystal drawing by horizontal magnetic field type Czochralski method |
| JP2010222241A (en) * | 2009-02-25 | 2010-10-07 | Sumco Corp | Silicon single crystal wafer for igbt and method for manufacturing silicon single crystal wafer for igbt |
| JP5993550B2 (en) | 2011-03-08 | 2016-09-14 | 信越半導体株式会社 | Manufacturing method of silicon single crystal wafer |
| JP5772553B2 (en) | 2011-12-06 | 2015-09-02 | 信越半導体株式会社 | Method for evaluating silicon single crystal and method for producing silicon single crystal |
| JP5733245B2 (en) | 2012-03-16 | 2015-06-10 | 信越半導体株式会社 | Manufacturing method of silicon single crystal wafer |
| JP6237605B2 (en) * | 2014-12-19 | 2017-11-29 | 信越半導体株式会社 | Method for producing silicon single crystal |
| JP2019094224A (en) | 2017-11-21 | 2019-06-20 | 信越半導体株式会社 | Method for growing silicon single crystal |
-
1991
- 1991-12-04 JP JP34892691A patent/JP2688137B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05155682A (en) | 1993-06-22 |
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