JP3079991B2 - Single crystal manufacturing apparatus and manufacturing method - Google Patents
Single crystal manufacturing apparatus and manufacturing methodInfo
- Publication number
- JP3079991B2 JP3079991B2 JP08044377A JP4437796A JP3079991B2 JP 3079991 B2 JP3079991 B2 JP 3079991B2 JP 08044377 A JP08044377 A JP 08044377A JP 4437796 A JP4437796 A JP 4437796A JP 3079991 B2 JP3079991 B2 JP 3079991B2
- Authority
- JP
- Japan
- Prior art keywords
- single crystal
- heat
- melt
- pulling
- crystal
- 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 - Lifetime
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Description
【０００１】[0001]
【発明の属する技術分野】本発明は、シリコン等の単結
晶の製造装置およびその装置を用いる単結晶の製造方法
に関し、特に熱酸化誘起積層欠陥が少なく、酸化膜耐圧
特性に優れた単結晶の製造に適する製造装置および製造
方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing a single crystal such as silicon and a method for producing a single crystal using the apparatus, and more particularly to a method for producing a single crystal having less thermal oxidation induced stacking faults and excellent oxide film breakdown voltage characteristics. The present invention relates to a manufacturing apparatus and a manufacturing method suitable for manufacturing.
【０００２】[0002]
【従来の技術】現在、シリコン等の単結晶はチョクラル
スキー法によって製造されることが多い。2. Description of the Related Art At present, single crystals such as silicon are often produced by the Czochralski method.
【０００３】図７は、チョクラルスキー法の実施状況を
示す概略断面図である。坩堝１は二重構造であり、内側
は石英容器1aで、外側は黒鉛容器1bで構成される。坩堝
１の外側には加熱ヒーター２が配置されており、坩堝１
内にはこの加熱ヒーターにより溶融された結晶原料の溶
融液５が収容されている。この溶融液５の表面に種結晶
３の下端を接触させて上方へ引き上げることによって、
その下端に溶融液５を凝固させて単結晶４を成長させ
る。これらの部品、部材は水冷式の金属チャンバー６内
に収容され、全体として単結晶製造装置を構成してい
る。FIG. 7 is a schematic sectional view showing the state of implementation of the Czochralski method. The crucible 1 has a double structure, the inside being a quartz container 1a and the outside being a graphite container 1b. A heater 2 is arranged outside the crucible 1,
The melt 5 of the crystal raw material melted by the heater is accommodated in the inside. By bringing the lower end of the seed crystal 3 into contact with the surface of the melt 5 and pulling it upward,
The melt 5 is solidified at its lower end to grow the single crystal 4. These components and members are housed in a water-cooled metal chamber 6 and constitute a single crystal manufacturing apparatus as a whole.
【０００４】[0004]
【発明が解決しようとする課題】単結晶シリコンウエー
ハの品質評価項目の主なものとして、熱酸化誘起積層欠
陥（以下、ＯＳＦと略記する）と、酸化膜耐圧特性が挙
げられる。これまでのところ、ＯＳＦの生成機構や酸化
膜耐圧特性を劣化させる欠陥の形成機構については未だ
十分に解明されていない。しかし、定性的には、結晶化
後の単結晶中の温度勾配がＯＳＦや酸化膜耐圧特性に大
きく影響すると言われている。The main evaluation items of the quality of a single crystal silicon wafer include thermal oxidation induced stacking faults (hereinafter abbreviated as OSF) and oxide film breakdown voltage characteristics. To date, the mechanism of generating OSFs and the mechanism of forming defects that degrade oxide breakdown voltage characteristics have not been sufficiently elucidated. However, qualitatively, it is said that the temperature gradient in the single crystal after crystallization greatly affects OSF and oxide film breakdown voltage characteristics.
【０００５】最近の報告では、1100〜800 ℃の温度域
(中〜低温領域) でＯＳＦ核形成が促進されるので、Ｏ
ＳＦ低減には1100〜800 ℃の温度域での急冷が効果的で
あるとされている (干川圭吾編著、培風館発行「バルク
結晶成長技術」59頁) 。In a recent report, the temperature range of 1100 to 800 ° C.
(Medium to low temperature region) promotes OSF nucleation,
It is said that rapid cooling in the temperature range of 1100 to 800 ° C. is effective for reducing SF (Ed. Keigo Hirakawa, published by Baifukan, “Bulk Crystal Growth Technology”, p. 59).
【０００６】一方、酸化膜耐圧特性については特性の不
良原因となる欠陥核が結晶固化時に発生し、この欠陥核
が1250℃以上の領域 (高温領域) で収縮することから、
酸化膜耐圧特性の向上には1250℃以上での徐冷が望まし
いとされている (第39回春季応用物理学会予稿集、30P-
ZD-17)。On the other hand, with respect to the oxide film breakdown voltage characteristics, a defect nucleus which causes a defect in the characteristics is generated at the time of crystal solidification, and this defect nucleus shrinks in a region (high temperature region) of 1250 ° C. or more.
It is considered that slow cooling at 1250 ° C or more is desirable to improve the oxide film breakdown voltage characteristics. (Proceedings of the 39th Spring Meeting of the Japan Society of Applied Physics, 30P-
ZD-17).
【０００７】本発明は、これまでに明らかになった上記
のような知見に基づいて、実際の単結晶引上に際し、理
想的な温度環境を整えることができる単結晶の製造装
置、およびそれを用いる単結晶の製造方法を提供するこ
とを課題とする。[0007] The present invention is based on the above-mentioned findings, which have been clarified so far, and provides a single crystal manufacturing apparatus capable of preparing an ideal temperature environment for pulling an actual single crystal. It is an object to provide a method for producing a single crystal to be used.
【０００８】具体的には、ＯＳＦ発生率の低減を目的
として1100℃〜800 ℃の温度域で急冷、酸化膜耐圧特
性の改善を目的として1250℃以上の温度域で徐冷、とい
う温度環境を実現し、ＯＳＦ発生率が少なく、酸化膜耐
圧特性に優れた単結晶の引上成長を可能とする製造装置
および製造方法を提供することを目的とする。More specifically, a temperature environment of rapid cooling in a temperature range of 1100 ° C. to 800 ° C. for the purpose of reducing the OSF generation rate and slow cooling in a temperature range of 1250 ° C. or more for the purpose of improving oxide film breakdown voltage characteristics is considered. It is an object of the present invention to provide a manufacturing apparatus and a manufacturing method which can realize a single crystal having a low OSF generation rate and an excellent oxide film breakdown voltage characteristic.
【０００９】なお、特開平７−413830号公報には、酸化
膜耐圧特性の改善を目的として、単結晶を1200〜850 ℃
の範囲で 200分以上保持するという発明が開示されてい
る。Japanese Patent Application Laid-Open No. 7-413830 discloses that a single crystal is heated at 1200 to 850 ° C. for the purpose of improving the oxide film breakdown voltage characteristics.
The invention of holding for 200 minutes or more in the range described above is disclosed.
【００１０】しかし、そこには高温域および中・低温域
の温度環境をともに制御するという思想、およびそれを
実現する装置上の工夫は何らなされていない。However, there is no idea to control both the temperature environment in the high-temperature region and the medium / low-temperature region, and no device has been devised to realize it.
【００１１】また、本出願人は、引き上げた単結晶を囲
繞して「耐熱断熱部材」を設置する発明を提案した (特
開平７−277887号) 。その発明は、例えば、黒鉛製の断
熱部材によって、単結晶の過度の冷却を防止するととも
に装置内のガスの流れを適切に制御することを主目的と
するものである。The present applicant has proposed an invention in which a "heat-resistant heat-insulating member" is provided around a single crystal that has been pulled up (Japanese Patent Laid-Open No. 7-277887). An object of the invention is to prevent excessive cooling of a single crystal and appropriately control the flow of gas in the apparatus, for example, by a heat insulating member made of graphite.
【００１２】[0012]
【課題を解決するための手段】本発明は、下記のシリコ
ン単結晶製造装置を要旨とする。SUMMARY OF THE INVENTION The gist of the present invention is the following silicon single crystal manufacturing apparatus.
【００１３】図１に示すように、成長させるべき単結晶
の原料溶融液５を収容する坩堝１と、この溶融液５を加
熱する手段２と、坩堝１内の溶融液５の表面に種結晶３
を接触させて単結晶４を成長させる引上げ手段９と、前
記各部材を収容する金属チャンバー６とを具備する単結
晶製造装置であって、単結晶の引上げ域の周囲を囲繞す
る円筒状、または上方から下方に向かうに従って縮径も
しくは拡径された筒状で、その反射率が 0.5以上の耐熱
反射部材７が、前述の溶融液５と金属チャンバー６との
間の単結晶の温度勾配を制御すべき位置に設けられてい
ることを特徴とする単結晶引上装置。As shown in FIG. 1, a crucible 1 containing a raw material melt 5 of a single crystal to be grown, a means 2 for heating the melt 5, and a seed crystal on the surface of the melt 5 in the crucible 1 3
A single crystal manufacturing apparatus comprising pulling means 9 for growing a single crystal 4 by contacting with each other, and a metal chamber 6 accommodating each of the above members, wherein the cylindrical shape surrounds a single crystal pulling area, or A heat-resistant reflecting member 7 having a diameter of not less than 0.5 and having a reflectance of 0.5 or more controls the temperature gradient of the single crystal between the melt 5 and the metal chamber 6 from the top to the bottom. A single crystal pulling apparatus, which is provided at a position where it should be.
【００１４】上記の単結晶の温度勾配を制御すべき位置
とは、先に述べた単結晶の高温域（約1250℃以上の温度
域) および中．低温域 (約1100〜800 ℃の温度域）であ
る。The positions at which the temperature gradient of the single crystal is to be controlled include the high temperature range (the temperature range of about 1250 ° C. or higher) of the single crystal and the medium. It is in the low temperature range (temperature range of about 1100 to 800 ° C).
【００１５】このような温度域での温度勾配を的確に制
御するには、耐熱反射部材７はその長さ( 高さ、ｈ1)が
50 〜250 mmで、その下端と溶融液面との間隔 (ｈ2)が
50mm以上となるように設置されることが望ましい。In order to accurately control the temperature gradient in such a temperature range, the length (height, h 1 ) of the heat-resistant reflecting member 7 is set to
50 to 250 mm, and the distance (h 2 ) between the lower end and the melt surface is
It is desirable to install it so that it becomes 50 mm or more.
【００１６】本発明はまた『上記の装置を用いて、単結
晶の高温域では徐冷、中・低温域では急冷となるように
単結晶の温度勾配を制御しつつ引上げを行うことを特徴
とする単結晶の製造方法』を要旨とする。The present invention is also characterized in that the pulling is performed while controlling the temperature gradient of the single crystal by using the above-mentioned apparatus so that the single crystal is gradually cooled in a high temperature range and rapidly cooled in a middle / low temperature range. Single crystal production method ”.
【００１７】図７からも明らかなように、引き上げられ
た結晶は、加熱ヒーター２や溶融液５の表面、および石
英坩堝1a等の高温部からの輻射を受けており、それが結
晶温度に大きな影響を与える。従って、この高温部から
結晶への輻射を制御することによって結晶の温度勾配を
制御することができる。すなわち、溶融液面と耐熱反射
部材との距離、耐熱反射部材の長さ等を制御することに
よって結晶各部の温度勾配を適正にすることができる。As is clear from FIG. 7, the pulled crystal is radiated from the surfaces of the heater 2 and the melt 5 and from a high-temperature portion such as the quartz crucible 1a. Affect. Therefore, the temperature gradient of the crystal can be controlled by controlling the radiation from the high temperature part to the crystal. That is, by controlling the distance between the melt surface and the heat-resistant reflective member, the length of the heat-resistant reflective member, and the like, the temperature gradient of each part of the crystal can be made appropriate.
【００１８】図２は、本発明の原理を模式的に示した概
略縦断面図である。(a) が、先に述べた急冷すべき領域
であり、(b) が徐冷すべき領域である。前記の溶融液等
の高温部からの輻射熱は結晶に向かって照射され、一部
は（ロ）に示すように(b) の領域に供給されて、その領
域を高温に保つ。一方、(a) の領域に向かう輻射熱は、
耐熱反射部材７が存在することによって、（イ）のよう
に反射される。そのため、(a) の領域には、（ハ）に示
すような放散熱が供給されることになるが、輻射熱に比
べ小さいものであるから、 (a)の領域の温度低下が促進
される。さらに、（イ）のように下方に反射された輻射
熱は、溶融液面で散乱して、一部は（ロ）に示すように
(b) の領域に供給される。FIG. 2 is a schematic longitudinal sectional view schematically showing the principle of the present invention. (a) is the area to be rapidly cooled as described above, and (b) is the area to be gradually cooled. The radiant heat from the high temperature part such as the melt is irradiated toward the crystal, and a part is supplied to the region (b) as shown in (b) to keep the region at a high temperature. On the other hand, the radiant heat toward the region (a) is
The presence of the heat-resistant reflecting member 7 causes reflection as shown in FIG. Therefore, the heat dissipated as shown in (c) is supplied to the area (a), but since the heat is smaller than the radiant heat, the temperature decrease in the area (a) is promoted. Further, the radiant heat reflected downward as in (a) is scattered on the surface of the molten liquid, and a part is radiated as shown in (b).
(b).
【００１９】上記のような原理で、単結晶の各部の温度
を適切に制御するには、耐熱反射部材７の設置位置、長
さおよび形状を適正に選ぶ必要がある。以下、それらに
ついて詳述する。In order to properly control the temperature of each part of the single crystal based on the above principle, it is necessary to appropriately select the installation position, the length and the shape of the heat-resistant reflection member 7. Hereinafter, they will be described in detail.
【００２０】[0020]
【発明の実施の形態】図１の（ａ）は本発明装置の一例
を示す軸心をとおる縦断面図であり、（ｂ）は（ａ）図
の要所のみを拡大して示す図である。これらの図におい
て、１は坩堝で、内側を石英容器1aとし、外側を黒鉛容
器1bとした二重構造であり、坩堝支持軸1c上に設置され
る。この坩堝支持軸1cは、坩堝の回転だけでなく、坩堝
の昇降にも使用ができるようになっている。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 (a) is a longitudinal sectional view taken along an axis showing an example of the apparatus of the present invention, and FIG. 1 (b) is an enlarged view of only the essential parts of FIG. is there. In these figures, reference numeral 1 denotes a crucible having a double structure having a quartz container 1a on the inside and a graphite container 1b on the outside, and is set on a crucible support shaft 1c. The crucible support shaft 1c can be used not only for rotating the crucible but also for raising and lowering the crucible.
【００２１】図中の水冷式の金属チャンバー６は、単結
晶の引上軸を中心として天井部6aと側壁6bから構成され
る円筒状の真空容器であり、その中央位置に坩堝１が配
設され、その外周にはこれを囲んで加熱ヒーター２が配
設されている。一方、坩堝１の上方には金属チャンバー
６の天井部6aの中央から引上げ手段９が回転および昇降
可能に垂設され、その下端には種結晶３が装着されてい
る。種結晶３は引上げ手段９によって回転しつつ上昇
し、溶融液５との接触面である下端部に単結晶４が成長
する。The water-cooled metal chamber 6 shown in the figure is a cylindrical vacuum vessel composed of a ceiling 6a and a side wall 6b centered on a single crystal pulling shaft, and the crucible 1 is disposed at the center of the vacuum chamber. A heater 2 is arranged around the periphery of the heater. On the other hand, above the crucible 1, a pulling means 9 is suspended from the center of the ceiling 6a of the metal chamber 6 so as to be rotatable and vertically movable, and a seed crystal 3 is mounted at the lower end thereof. Seed crystal 3 rises while being rotated by pulling means 9, and single crystal 4 grows at the lower end, which is the contact surface with melt 5.
【００２２】図１（ｂ）に示すように、本発明装置には
引上げ手段９と同軸に長さ（高さ）ｈ1 の耐熱反射部材
７が、融液面との高さｈ2 の位置に、単結晶の引上げ域
の一部の周囲を囲むように配置される。As shown in FIG. 1 (b), the heat reflecting member 7 of the present invention in the apparatus lifting means 9 coaxially to the length (height) h 1 is at a height h 2 between the melt surface Is arranged to surround a part of the single crystal pulling region.
【００２３】耐熱反射部材７の形状は、例えば図３に示
すような（ａ）の下方に向かって縮径する円筒状（ここ
では、便宜的に「逆円錐筒」という）、（ｂ）の下方に
向かって拡径する円筒状（ここでは、便宜的に「円錐
筒」という）、（ｃ）の径が一定の円筒、および（ｄ）
の円筒と円錐筒を合わせた形状（ここでは、これも「逆
円錐筒」の一つとする）が考えられる。The shape of the heat-resistant reflecting member 7 is, for example, a cylindrical shape (herein referred to as an "inverted conical cylinder" for convenience) whose diameter is reduced downward as shown in FIG. A cylindrical shape whose diameter increases downward (herein referred to as a “conical cylinder” for convenience), a cylinder having a constant diameter in (c), and (d)
(Here, this is also referred to as one of the "inverted conical cylinders").
【００２４】図４は、前記の逆円錐筒の耐熱反射部材７
を支持部材21によって金属チャンバーの天井部6aに取り
付ける態様の一例を示す縦断面図である。同図（ａ）は
支持部材21による保持状況の縦断面図であり、同図
（ｂ）はＡ−Ａ矢視による水平断面図である。また、同
図（ｃ）は耐熱反射部材７の斜視図である。この例で
は、四個の角棒状の支持部材21が天井部6aに90°の間隔
で配置され、支持部材21と締め付けボルト21a によっ
て、耐熱反射部材７の上端部を保持する。ここで、支持
部材21の数は上記の４個に限定されるものでなく、その
形状も角棒状のものに限る必要はない。FIG. 4 shows the heat-resistant reflecting member 7 of the above-mentioned inverted conical cylinder.
FIG. 6 is a longitudinal cross-sectional view showing an example of a mode in which is attached to a ceiling 6a of a metal chamber by a support member 21. FIG. 7A is a vertical cross-sectional view of a holding state by the support member 21, and FIG. 7B is a horizontal cross-sectional view taken along the line AA. FIG. 2C is a perspective view of the heat-resistant reflective member 7. In this example, four square rod-shaped support members 21 are arranged at 90 ° intervals on the ceiling 6a, and the upper end of the heat-resistant reflection member 7 is held by the support members 21 and the fastening bolts 21a. Here, the number of the support members 21 is not limited to the four described above, and the shape does not need to be limited to a square rod shape.
【００２５】図５は、後述する実施例１と同じ条件で、
耐熱反射板７の反射率だけを 0.5、0.7 および0.9 と変
化させた場合の結晶温度勾配への影響を示したグラフで
ある。なお、結晶温度勾配とは、結晶の長さ (高さ方
向) の１mmごとに低下する温度である。FIG. 5 shows the same conditions as in Example 1 described later.
6 is a graph showing the effect on the crystal temperature gradient when only the reflectance of the heat-resistant reflector 7 is changed to 0.5, 0.7 and 0.9. The crystal temperature gradient is a temperature that decreases every 1 mm of the length (height direction) of the crystal.
【００２６】図示のとおり、反射率が大きくなるにつれ
て、液面から 150〜350 mm離れた位置での結晶温度勾配
が大きくなる。この位置は、前記の「急冷が望ましい領
域」に相当する。なお、液面に近い「徐冷が望ましい範
囲」では、反射率の影響は顕著ではないが、耐熱反射部
材がある場合の方がやや温度勾配が小さくなっている。
上記の試験結果から、温度勾配制御を効果的に行うため
には、耐熱反射部材７は、反射率 0.5以上であることが
望ましいと言える。As shown, as the reflectivity increases, the crystal temperature gradient at a position 150 to 350 mm away from the liquid surface increases. This position corresponds to the aforementioned “area where rapid cooling is desired”. In the “range where cooling slowly is desirable” close to the liquid surface, the influence of the reflectance is not remarkable, but the temperature gradient is slightly smaller when the heat-resistant reflective member is provided.
From the above test results, it can be said that it is desirable that the heat-resistant reflective member 7 has a reflectance of 0.5 or more in order to effectively control the temperature gradient.
【００２７】耐熱反射部材７の材料としては、例えば、
モリブデン（Ｍｏ）を用いることができる。Ｍｏが耐熱
性に優れ、反射率が大きいからである。前記の 0.5以上
という反射率は、Ｍｏの表面を十分に研磨することによ
って得られる。しかし、耐熱反射部材７の材質はＭｏに
限定されるものではなく、単結晶製造工程での劣化が少
なく、結晶品質に悪影響を与えない物質であれば良い。
また、表面だけをＭｏとした複合材料を使用することも
できる。As a material of the heat-resistant reflection member 7, for example,
Molybdenum (Mo) can be used. Mo is excellent in heat resistance and has a high reflectance. The reflectance of 0.5 or more can be obtained by sufficiently polishing the surface of Mo. However, the material of the heat-resistant reflective member 7 is not limited to Mo, and any material may be used as long as it does not deteriorate in the single crystal manufacturing process and does not adversely affect the crystal quality.
Further, a composite material in which only the surface is Mo can be used.
【００２８】耐熱反射部材７は、溶融液面５とチャンバ
ー６の天井部6aとの間で、単結晶の温度勾配を制御すべ
き位置に設置する。ただし、その下端と溶融液面との間
隔（ｈ2 ）は、50mm以上とするのがよい。これは、溶融
液面５の上を流れる不活性ガス (アルゴン)31 の流れが
溶融液面に与える影響を小さくするためである。溶融液
面５の上を流れるガスの流速は結晶に取り込まれる酸素
量に大きく影響する。The heat-resistant reflecting member 7 is provided between the melt surface 5 and the ceiling 6a of the chamber 6 at a position where the temperature gradient of the single crystal is to be controlled. However, the distance (h 2 ) between the lower end and the melt surface is preferably 50 mm or more. This is to reduce the influence of the flow of the inert gas (argon) 31 flowing on the melt surface 5 on the melt surface. The flow velocity of the gas flowing over the melt surface 5 greatly affects the amount of oxygen taken into the crystal.
【００２９】耐熱反射部材７の高さ（ｈ1 ）は、前記の
温度勾配を制御すべき領域の前部または一部を囲繞する
長さとする。装置および引き上げ条件にもよるが、一般
的な装置での通常の操業では、ｈ1 は50〜250 mmの範囲
で選べば最も効果的である。The height (h 1 ) of the heat-resistant reflection member 7 is set to a length surrounding the front part or a part of the area where the temperature gradient is to be controlled. Depending on the device and pulling conditions, in normal operation of a typical device, h 1 is the most effective to choose the range of 50 to 250 mm.
【００３０】50mm未満では効果が顕著でなく、250mm よ
りも大きくしても効果の増大は小さい。また、あまりに
大きくすると通常の装置では前記のｈ2 の望ましい値が
確保しにくくなる。If the diameter is less than 50 mm, the effect is not remarkable, and if the diameter is larger than 250 mm, the increase in the effect is small. Further, the desired value of said h 2 becomes difficult to secure in when too large conventional equipment.
【００３１】なお、図１（ｂ) に示した単結晶直胴部と
耐熱反射部材７との最近接距離Ｒ1は、小さいほど温度
勾配への影響を大きくすることができるが、結晶の直径
変動や中心軸からの振れを考慮して、20〜40mmであるこ
とが望ましい。The smaller the closest distance R 1 between the single-crystal straight body and the heat-resistant reflective member 7 shown in FIG. 1B, the greater the influence on the temperature gradient. It is desirable that the thickness be 20 to 40 mm in consideration of fluctuation and deflection from the central axis.
【００３２】図６は、図３（ａ）に示す形状の耐熱反射
板の下端部内径を 200mm、 240mmと変化させ、単結晶と
の最近接距離Ｒ1 を変え、その距離と単結晶の温度勾配
との関係を調べた結果を示すグラフである。他の条件
は、後述する実施例１と同じにした。この結果からＲ1
が小さいほど温度勾配改善の効果が大きいことが分か
る。FIG. 6 shows that the inner diameter at the lower end of the heat-resistant reflector having the shape shown in FIG. 3A is changed to 200 mm and 240 mm, the closest distance R 1 to the single crystal is changed, and the distance and the temperature of the single crystal are changed. It is a graph which shows the result of having investigated the relation with a gradient. Other conditions were the same as in Example 1 described later. From this result, R 1
It can be seen that the effect of improving the temperature gradient is greater as the value is smaller.
【００３３】上述の耐熱反射部材は、製造装置の方式・
型式や容量に限定されることなく適用することができ
る。すなわち、先に述べた特開平７−277887号で提案さ
れた耐熱断熱性部材と併用しても有効である。具体的に
は、本発明の耐熱反射部材を、先願の耐熱断熱性部材の
内部に設置することによって、高温領域の徐冷と中・低
温領域の急冷の効果を一層高めることができることを確
認している。The above-mentioned heat-resistant reflective member is manufactured by a method of a manufacturing apparatus.
The present invention can be applied without being limited to the model and the capacity. That is, it is effective even when used in combination with the heat- and heat-insulating member proposed in the above-mentioned JP-A-7-277887. Specifically, it was confirmed that by installing the heat-resistant reflective member of the present invention inside the heat-insulated heat-insulating member of the prior application, it was possible to further enhance the effects of slow cooling in a high-temperature region and rapid cooling in a medium / low-temperature region. doing.
【００３４】本発明の装置を用いて単結晶を製造するに
際しては、単結晶製造装置の形状、単結晶の直径や、要
求される酸化膜耐圧特性、ＯＳＦ密度の上限などの品質
に応じて、まず耐熱反射部材の形状を定め、あらかじめ
前述のｈ1 およびｈ2 を最適の値とし、単結晶の引上げ
を行う。以下、本発明の装置の効果を、実施例に基づい
て具体的に説明する。When a single crystal is manufactured using the apparatus of the present invention, depending on the quality of the single crystal manufacturing apparatus, such as the shape of the single crystal, the diameter of the single crystal, required oxide film breakdown voltage characteristics, and the upper limit of the OSF density. First, the shape of the heat-resistant reflecting member is determined, and the above-mentioned h 1 and h 2 are set to optimal values in advance, and the single crystal is pulled. Hereinafter, the effects of the device of the present invention will be specifically described based on examples.
【００３５】[0035]
【実施例１】図１に示した本発明の製造装置において、
耐熱反射部材７として図３（ａ）に示す逆円錐筒状のモ
リブデン（Mo）製のものを使用した。その寸法は、高さ
ｈ1が 130mm、上端部内径 360mm、下端部内径 200mm、
肉厚２mmである。これを図４（ａ）の支持部材21を介し
て耐熱反射部材７の下端と溶融液面５との間隔ｈ2 が20
0mmとなるように単結晶の引上軸９とほぼ同軸に配設し
た。なお、耐熱反射部材７のは反射率 0.72 の研磨面と
した。Embodiment 1 In the manufacturing apparatus of the present invention shown in FIG.
As the heat-resistant reflecting member 7, an inverted conical cylindrical member made of molybdenum (Mo) shown in FIG. 3A was used. Its dimensions are a height h 1 is 130 mm, the upper end inside diameter 360 mm, lower end inner diameter of 200 mm,
The thickness is 2 mm. The distance h 2 between the lower end of the heat-resistant reflective member 7 and the melt surface 5 is reduced to 20 by the support member 21 shown in FIG.
It was arranged almost coaxially with the single crystal pulling shaft 9 so as to be 0 mm. The heat-resistant reflective member 7 had a polished surface with a reflectance of 0.72.
【００３６】引き上げた単結晶４は直径６インチのシリ
コン単結晶であって、石英坩堝1aは内径 (φ) が450mm
(18 インチ) のものを使用し、金属チャンバー６内に流
入するアルゴンガス流量は30リットル/minの条件で、引
き上げ速度は 0.8mm/minとし、引き上げ長さは1200mmと
した。The single crystal 4 is a silicon single crystal having a diameter of 6 inches, and the quartz crucible 1a has an inner diameter (φ) of 450 mm.
(18 inches), the flow rate of argon gas flowing into the metal chamber 6 was 30 l / min, the pulling speed was 0.8 mm / min, and the pulling length was 1200 mm.
【００３７】更に、比較例として、同じ条件で耐熱反射
部材７のない装置でも引き上げを実施した。Further, as a comparative example, pulling up was carried out in an apparatus without the heat-resistant reflecting member 7 under the same conditions.
【００３８】得られた単結晶は、ＯＳＦ良品率と酸化膜
耐圧良品率の試験項目で評価した。The obtained single crystal was evaluated by the test items of the OSF conformity rate and the oxide film breakdown voltage conformity rate.
【００３９】ＯＳＦ良品率は、シリコンウエーハを切り
出し、 780℃×3Hr および1000℃×16Hrの熱処理をした
のち、選択エッチングし、ＯＳＦ欠陥が基準値（10個/c
m2) 以下のものを良品とし、ＯＳＦ良品ウエーハ枚数と
全ウエーハ枚数の比で表す。The OSF non-defective rate is determined by cutting a silicon wafer, performing a heat treatment at 780 ° C. × 3 hours and a temperature of 1000 ° C. × 16 hours, and selectively etching.
m 2 ) The following items are defined as non-defective products, and are represented by the ratio of the number of OSF non-defective wafers to the total number of wafers.
【００４０】酸化膜耐圧良品率は、電圧ランピング法に
よる評価であり、ゲート電極は燐（Ｐ）ドープの多結晶
シリコンで構成し、膜厚 250Åのドライ酸化膜で、その
面積は８mm2 として、良品は基準値 (平均電界８Mv/cm)
以上でも絶縁破壊しないウエーハを良品と判定し、その
比率で表した。The oxide film breakdown voltage non-defective rate is evaluated by a voltage ramping method. The gate electrode is composed of phosphorus (P) -doped polycrystalline silicon, is a dry oxide film having a thickness of 250 mm, and has an area of 8 mm 2 . Good value is standard value (average electric field 8Mv / cm)
Wafers that did not undergo dielectric breakdown were judged to be non-defective, and the ratio was expressed.
【００４１】以上の試験結果を表１に示す。Table 1 shows the test results.
【００４２】[0042]
【表１】 [Table 1]
【００４３】表１に示すように、本発明の装置を使用
し、本発明方法で製造したシリコン単結晶は、比較例の
方法で製造したものに比べ、全ての試験項目について良
好な結果となっている。As shown in Table 1, the silicon single crystal produced by the method of the present invention using the apparatus of the present invention gave better results for all the test items than those produced by the method of the comparative example. ing.
【００４４】[0044]
【実施例２】図３に示した４種類の形状の耐熱反射部材
を用いて、実施例１と同じ条件でシリコン単結晶の引上
げを行い、単結晶の1100℃〜800 ℃領域と、1250℃以上
の領域での温度勾配の変化を測定した。その結果を表２
に示す。EXAMPLE 2 A silicon single crystal was pulled under the same conditions as in Example 1 using the heat-resistant reflective members of the four types shown in FIG. 3 to obtain a single crystal region of 1100 ° C. to 800 ° C. and 1250 ° C. The change in the temperature gradient in the above region was measured. Table 2 shows the results.
Shown in
【００４５】なお、耐熱反射部材の共通寸法は、高さｈ
1 が 130mm、肉厚が２mm、溶融液面５からの距離ｈ2 は
200mmである。その他の寸法は表２中に示した。材質は
モリブデンで、反射率 0.72 に研磨したものである。上
端部内径と下端部内径は表２中に示す。The common dimension of the heat-resistant reflecting member is the height h.
1 is 130 mm, wall thickness is 2 mm, and distance h 2 from the melt surface 5 is
200 mm. Other dimensions are shown in Table 2. The material is molybdenum, polished to a reflectance of 0.72. The inner diameter of the upper end and the inner diameter of the lower end are shown in Table 2.
【００４６】[0046]
【表２】 [Table 2]
【００４７】表２に示すように、耐熱反射部材の形状の
変更により、1100℃〜800 ℃の温度域と、1250℃以上の
温度域とにおける温度勾配への効果をそれぞれ変更する
ことができる。測定結果から、望ましい形状は（ａ）円
錐筒および（ｄ）の円錐と円筒の組合せであると言える
が、特に、1250℃以上の温度域で徐冷を行いたい場合に
は、（ｂ）円錐筒を用いるのが有効である。例えば、特
定の製造装置において、ＯＳＦ品質は問題ないが酸化膜
耐圧特性が劣るような場合に、（ｂ）円錐筒の耐熱反射
部材を用いることによって、いずれの品質も満足する単
結晶を製造できることを確認している。As shown in Table 2, the effect on the temperature gradient in the temperature range of 1100 ° C. to 800 ° C. and the temperature range of 1250 ° C. or more can be changed by changing the shape of the heat-resistant reflecting member. From the measurement results, it can be said that the desirable shapes are (a) the conical cylinder and the combination of the cone and the cylinder in (d). In particular, when it is desired to perform slow cooling in a temperature range of 1250 ° C. or more, the (b) cone It is effective to use a cylinder. For example, in a case where the OSF quality is not a problem but the oxide film breakdown voltage characteristics are poor in a specific manufacturing apparatus, (b) a single crystal satisfying both qualities can be manufactured by using a heat-resistant reflective member having a conical cylinder. Have confirmed.
【００４８】[0048]
【発明の効果】本発明の装置を使用する単結晶の製造方
法によれば、耐熱反射部材が加熱ヒーターや石英坩堝、
溶融液面から結晶への輻射熱を遮断し、高温域では徐
冷、中・低温域では急冷となるように単結晶の温度勾配
を制御するので、引き上げられる単結晶は、ＯＳＦが減
少し、かつ、酸化膜耐圧特性の向上したものとなる。According to the method for producing a single crystal using the apparatus of the present invention, the heat-resistant reflecting member is made of a heater, a quartz crucible,
Since the radiant heat from the melt surface to the crystal is cut off and the temperature gradient of the single crystal is controlled so as to be gradually cooled in the high temperature range and quenched in the middle and low temperature range, the OSF of the pulled single crystal decreases, and Thus, the oxide film withstand voltage characteristics are improved.
【図１】（ａ）は本発明の単結晶製造装置を示す縦断面
図、（ｂ）はその要部拡大図である。FIG. 1A is a longitudinal sectional view showing a single crystal manufacturing apparatus of the present invention, and FIG. 1B is an enlarged view of a main part thereof.
【図２】本発明の原理を説明する単結晶周辺の概略断面
図である。FIG. 2 is a schematic sectional view around a single crystal for explaining the principle of the present invention.
【図３】耐熱反射部材のいくつかの形状例を示す縦断面
図と斜視図である。FIG. 3 is a longitudinal sectional view and a perspective view showing some examples of the shape of a heat-resistant reflecting member.
【図４】耐熱反射部材の保持状況の一例を示す図であ
り、（ａ）は縦断面図、（ｂ）は水平断面図、（ｃ）は
保持される耐熱反射部材の斜視図である。4A and 4B are diagrams illustrating an example of a holding state of the heat-resistant reflective member, wherein FIG. 4A is a longitudinal sectional view, FIG. 4B is a horizontal sectional view, and FIG. 4C is a perspective view of the held heat-resistant reflective member.
【図５】耐熱反射部材の反射率を変えて結晶成長方向で
の温度勾配への影響を調べた結果を示すグラフである。FIG. 5 is a graph showing the results of examining the effect on the temperature gradient in the crystal growth direction by changing the reflectance of the heat-resistant reflective member.
【図６】耐熱反射部材と結晶との最近接距離を変えて結
晶成長方向での温度勾配への影響を調べた結果を示すグ
ラフである。FIG. 6 is a graph showing the result of examining the effect on the temperature gradient in the crystal growth direction by changing the closest distance between the heat-resistant reflective member and the crystal.
【図７】チョクラルスキー法の実施状況を示す概略断面
図である。FIG. 7 is a schematic cross-sectional view showing an implementation state of the Czochralski method.
１：坩堝、 1a：石英製容器、
1b：黒鉛製容器、1c：坩堝支持軸、 ２：加
熱ヒーター、 ３：種結晶、４：引上げ結晶、
５：溶融液、 ６：金属チャンバ
ー、6a：チャンバーの天井部、 6b：チャンバーの側
壁、 ７：耐熱反射部材、7a：貫通孔、
８：排出口、 ９：引上げ手段、10：耐
熱断熱性部材 21：支持部材、 21a：締め付けボルト、
30、31：ガス流れ1: Crucible, 1a: Quartz container,
1b: graphite container, 1c: crucible support shaft, 2: heater, 3: seed crystal, 4: pulled crystal,
5: melt, 6: metal chamber, 6a: ceiling of chamber, 6b: side wall of chamber, 7: heat-resistant reflective member, 7a: through hole,
8: outlet, 9: pulling means, 10: heat-resistant and heat-insulating member 21: support member, 21a: fastening bolt,
30, 31: Gas flow
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) C30B 1/00 - 35/00 ──────────────────────────────────────────────────続 き Continuation of front page (58) Field surveyed (Int.Cl. 7 , DB name) C30B 1/00-35/00
Claims (3)
する坩堝と、この溶融液を加熱する手段と、坩堝内の溶
融液の表面に種結晶を接触させて単結晶を成長させる引
上げ手段と、前記各部材を収容する金属チャンバーとを
具備する単結晶製造装置であって、単結晶の引上げ域の
周囲を囲繞する円筒状、または上方から下方に向かうに
従って縮径もしくは拡径された筒状で、その反射率が
0.5以上の耐熱反射部材が、溶融液と金属チャンバーの
間の単結晶の温度勾配を制御すべき位置に設けられてい
ることを特徴とする単結晶引上装置。1. A crucible containing a single crystal raw material melt to be grown, a means for heating the melt, and a pulling means for growing a single crystal by bringing a seed crystal into contact with the surface of the melt in the crucible. And a metal chamber for accommodating each of the members, wherein the single crystal is a cylindrical shape surrounding a single crystal pulling region, or a tube whose diameter is reduced or expanded from the top to the bottom. And its reflectance is
A single crystal pulling apparatus, wherein a heat resistant reflecting member of 0.5 or more is provided at a position where a temperature gradient of the single crystal between the melt and the metal chamber is to be controlled.
て、その下端が溶融液面から50mm以上の間隔をもって設
置されている請求項１に記載の単結晶引上装置。2. The single crystal pulling apparatus according to claim 1, wherein the height of the heat-resistant reflecting member is 50 to 250 mm, and the lower end thereof is provided at an interval of 50 mm or more from the surface of the molten liquid.
用し、単結晶の高温域では徐冷、低温域では急冷となる
ように単結晶の温度勾配を制御しつつ引上げを行うこと
を特徴とする単結晶の製造方法。3. An apparatus according to claim 1 or 2, wherein the pulling is performed while controlling the temperature gradient of the single crystal so that the single crystal is gradually cooled in a high temperature region and rapidly cooled in a low temperature region. The manufacturing method of the single crystal characterized by the above-mentioned.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08044377A JP3079991B2 (en) | 1996-03-01 | 1996-03-01 | Single crystal manufacturing apparatus and manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08044377A JP3079991B2 (en) | 1996-03-01 | 1996-03-01 | Single crystal manufacturing apparatus and manufacturing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09235174A JPH09235174A (en) | 1997-09-09 |
| JP3079991B2 true JP3079991B2 (en) | 2000-08-21 |
Family
ID=12689824
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP08044377A Expired - Lifetime JP3079991B2 (en) | 1996-03-01 | 1996-03-01 | Single crystal manufacturing apparatus and manufacturing method |
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| Country | Link |
|---|---|
| JP (1) | JP3079991B2 (en) |
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|---|---|---|---|---|
| KR20030058714A (en) * | 2001-12-31 | 2003-07-07 | 주식회사 실트론 | Thermal shield in Apparatus of growing a single crystalline silicon ingot and method for fabricating single crystalline silicon ingot using thereof |
| JP5439972B2 (en) * | 2009-06-19 | 2014-03-12 | 株式会社Ｓｕｍｃｏ | Manufacturing method of large-diameter silicon single crystal |
| CN111334853A (en) * | 2020-04-03 | 2020-06-26 | 大连连城数控机器股份有限公司 | Heat radiation reflection device for improving growth speed of czochralski single crystal |
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1996
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Also Published As
| Publication number | Publication date |
|---|---|
| JPH09235174A (en) | 1997-09-09 |
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