JPH0891983A - Method for pulling up silicon single crystal - Google Patents

Method for pulling up silicon single crystal

Info

Publication number
JPH0891983A
JPH0891983A JP22195294A JP22195294A JPH0891983A JP H0891983 A JPH0891983 A JP H0891983A JP 22195294 A JP22195294 A JP 22195294A JP 22195294 A JP22195294 A JP 22195294A JP H0891983 A JPH0891983 A JP H0891983A
Authority
JP
Japan
Prior art keywords
pulling
single crystal
temperature
silicon single
ingot
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.)
Granted
Application number
JP22195294A
Other languages
Japanese (ja)
Other versions
JP3149320B2 (en
Inventor
Kazuhiro Harada
和浩 原田
Hideo Tanaka
英夫 田中
Toshihiko Watanabe
敏彦 渡辺
Hisashi Furuya
久 降屋
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Materials Silicon Corp
Mitsubishi Materials Corp
Original Assignee
Mitsubishi Materials Silicon Corp
Mitsubishi Materials Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mitsubishi Materials Silicon Corp, Mitsubishi Materials Corp filed Critical Mitsubishi Materials Silicon Corp
Priority to JP22195294A priority Critical patent/JP3149320B2/en
Publication of JPH0891983A publication Critical patent/JPH0891983A/en
Application granted granted Critical
Publication of JP3149320B2 publication Critical patent/JP3149320B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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  • Crystals, And After-Treatments Of Crystals (AREA)
  • Liquid Deposition Of Substances Of Which Semiconductor Devices Are Composed (AREA)

Abstract

PURPOSE: To prevent both an oxidation induced stacking fault (OSF) and an oxygen deposit from being caused in a silicon wafer in heat treatment by lowering the temperature of a silicon single crystal ingot during the pulling up under specific conditions. CONSTITUTION: This method for pulling up a silicon single crystal is to house a silicon melt 7 in a quartz crucible 4 supported on a rotating shaft 3 under the interior of an apparatus 2 for pulling up an ingot, dipping a seed crystal 9 attached to the tip of a pulling up shaft 8 in the melt while heating the silicon melt with a heater 6 installed between a heat insulating unit 5 and the crucible 4, pull up the silicon single crystal ingot 11 at 0.6-2.0mm/min pulling up speed, passing a current through an auxiliary heater 10 at a temperature within the range of 1130-1070 deg.C in the temperature lowering temperature distribution, reduce the temperature lowering speed to 0-0.3 deg.C/min and keep the temperature lowering rate for at least 10min.

Description

【発明の詳細な説明】Detailed Description of the Invention

【0001】[0001]

【産業上の利用分野】本発明は欠陥発生の著しく少ない
シリコン(Si)単結晶インゴットの引上げ方法に関す
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 (Si) single crystal ingot with extremely few defects.

【0002】[0002]

【従来の技術】図8に示すように、一般にシリコン単結
晶インゴット1は、インゴット引上げ装置2内の下部に
回転軸3により支持された石英坩堝4内に保持されたシ
リコン融液7から引上げられる。同時にシリコン単結晶
インゴット1は保温体5と坩堝4の間に設けたヒータ6
により加熱されたシリコン融液7に、引上げ軸8の先端
に取付けた種結晶9を漬け、この引上げ軸8を回転させ
ながら、例えば1mm/分の速度で引上げることにより
製造されている。このため、引上げ直後のシリコン単結
晶インゴットは、その長さが例えば30cmの場合、下
端部の約1400℃から漸次上端部の約800℃までの
降下温度分布をもち、かつ引上げ速度が、上記の通り約
1mm/分であれば、その育成時間は約300分(約5
時間)を要するものである。
2. Description of the Related Art Generally, as shown in FIG. 8, a silicon single crystal ingot 1 is pulled up from a silicon melt 7 held in a quartz crucible 4 supported by a rotating shaft 3 in a lower portion of an ingot pulling apparatus 2. . At the same time, the silicon single crystal ingot 1 has a heater 6 provided between the heat retaining body 5 and the crucible 4.
It is manufactured by immersing the seed crystal 9 attached to the tip of the pulling shaft 8 in the silicon melt 7 heated by, and pulling it at a speed of, for example, 1 mm / min while rotating the pulling shaft 8. Therefore, when the length of the silicon single crystal ingot immediately after pulling is, for example, 30 cm, it has a temperature drop distribution from about 1400 ° C. at the lower end to about 800 ° C. at the upper end, and the pulling speed is the same as above. If it is about 1 mm / min, the growing time will be about 300 minutes (about 5
It takes time).

【0003】[0003]

【発明が解決しようとする課題】しかし、引上げられた
シリコン単結晶インゴットは、過飽和の酸素を含有する
ため、これには酸素析出物形成のもととなる多数の核が
存在し、このため半導体デバイス工程において、上記シ
リコン単結晶インゴットから製造したウェーハに種々の
高温処理が施されると、上記ウェーハには上記核を中心
にして酸素析出物が形成されるようになり、この酸素析
出物の形成は転位や積層欠陥(OSF:oxidation indu
ced stacking fault)などの欠陥発生の原因となり、し
かもこれらの欠陥は半導体デバイスの絶縁耐圧不良や、
キャリアのライフタイム減少などの重大な特性劣化を招
く。この点を解決するために、通常引上げ速度を0.4
mm/分程度に減速することにより、酸素析出物や積層
欠陥のもととなる核の発生を抑制している。しかし、こ
の0.4mm/分程度の引上げ速度でシリコン単結晶イ
ンゴットを引上げた場合には、生産性が悪い不具合があ
る。
However, since the pulled silicon single crystal ingot contains supersaturated oxygen, there are a large number of nuclei that form oxygen precipitates. In the device step, when various high temperature treatments are applied to the wafer manufactured from the silicon single crystal ingot, oxygen precipitates are formed on the wafer centering on the nucleus, and the oxygen precipitates are formed. The formation of dislocations and stacking faults (OSF: oxidation indu
ced stacking fault), and these defects cause the breakdown voltage of semiconductor devices and
It causes serious deterioration of characteristics such as reduction of carrier lifetime. In order to solve this point, the normal pulling speed is 0.4
By reducing the speed to about mm / min, the generation of nuclei that are the source of oxygen precipitates and stacking faults is suppressed. However, when the silicon single crystal ingot is pulled at a pulling rate of about 0.4 mm / min, there is a problem that productivity is poor.

【0004】本発明の目的は、半導体デバイス工程で熱
処理したときにシリコンウェーハに発現する積層欠陥及
び酸素析出物の要因をシリコン単結晶インゴットの引上
げ時に生じさせないシリコン単結晶の引上げ方法を提供
することにある。本発明の別の目的は、生産性の高いシ
リコン単結晶の引上げ方法を提供することにある。
An object of the present invention is to provide a method for pulling a silicon single crystal that does not cause stacking faults and oxygen precipitates that appear in a silicon wafer when heat-treated in a semiconductor device process when pulling a silicon single crystal ingot. It is in. Another object of the present invention is to provide a method for pulling a silicon single crystal with high productivity.

【0005】[0005]

【課題を解決するための手段】図7に示すように、本発
明は引上げ装置12内の坩堝4に保持されたシリコン融
液7からシリコン単結晶インゴット11を引上げる方法
の改良である。その特徴ある構成は、0.6〜2.0m
m/分の引上げ速度で引上げつつあるシリコン単結晶イ
ンゴット11の降下温度分布のうち1130〜1070
℃の温度範囲で降温速度を0〜0.3℃/分に減速して
この降温速度を少なくとも10分間保持することにより
引上げ後熱処理したときにシリコンウェーハに積層欠陥
及び酸素析出物を生じさせないようにすることにある。
As shown in FIG. 7, the present invention is an improvement of a method for pulling a silicon single crystal ingot 11 from a silicon melt 7 held in a crucible 4 in a pulling device 12. Its characteristic structure is 0.6 to 2.0 m.
1130 to 1070 of the temperature drop distribution of the silicon single crystal ingot 11 being pulled up at a pulling rate of m / min
In the temperature range of 0 ° C, the temperature decrease rate is reduced to 0 to 0.3 ° C / minute and the temperature decrease rate is maintained for at least 10 minutes so that stacking faults and oxygen precipitates do not occur in the silicon wafer when heat-treated after pulling. Is to

【0006】以下、本発明を詳述する。本発明の降温速
度を減速させる手段としては、引上げ速度を遅くせずに
引上げつつあるシリコン単結晶インゴットの周囲を保温
材で被包するか、もしくは補助ヒータで加熱する方法な
どがある。降温速度を設定するための温度測定法は、本
発明の目的を達成されれば、特に限定されないが、この
方法には例えば実施例1に示されるようにシリコン単結
晶インゴットに取付けた熱電対の温度測定データに基づ
く方法や、或いは非接触型の赤外線温度センサによって
引上げつつあるシリコン単結晶インゴットの温度を測定
する方法等がある。
The present invention will be described in detail below. As a means for reducing the temperature lowering rate of the present invention, there is a method in which the periphery of the silicon single crystal ingot which is being pulled up is wrapped with a heat insulating material without slowing down the pulling rate, or is heated by an auxiliary heater. The temperature measuring method for setting the temperature lowering rate is not particularly limited as long as the object of the present invention is achieved, but this method includes, for example, a thermocouple attached to a silicon single crystal ingot as shown in Example 1. There is a method based on temperature measurement data, or a method of measuring the temperature of a silicon single crystal ingot which is being pulled up by a non-contact type infrared temperature sensor.

【0007】本発明の引上げ速度は0.6〜2.0mm
/分の範囲にある。0.6mm/分未満では生産性に劣
り、2.0mm/分を越えると単結晶での成長が困難と
なる等の問題がある。またシリコン単結晶インゴットの
降下温度分布のうち1130〜1070℃の温度範囲で
降温速度を0〜0.3℃/分に減速するのは、種々の実
験結果から経験的に定めたものであり、1130〜10
70℃での降温速度が0.3℃/分を越えても、また降
温速度を0〜0.3℃/分に減速する温度範囲が113
0℃を越えても、1070℃未満であっても、シリコン
単結晶インゴットを引上げ後熱処理したときにシリコン
ウェーハ中の積層欠陥及び酸素析出物の発生を十分に抑
制することができない。上記温度範囲は1120〜10
80℃がより好ましい。また降温速度0℃/分は該当す
る温度で降温を停止し、保持することを意味する。更に
降温速度の保持時間は少なくとも10分間、好ましくは
10分間以上15時間である。生産性の向上とエネルギ
消費の観点から10分間以上3時間未満がより好まし
く、1時間以上2時間以下が更に好ましい。
The pulling speed of the present invention is 0.6 to 2.0 mm.
/ Minute range. If it is less than 0.6 mm / min, the productivity is inferior, and if it exceeds 2.0 mm / min, there is a problem that it is difficult to grow a single crystal. Further, it is empirically determined from various experimental results that the cooling rate is reduced to 0 to 0.3 ° C./min in the temperature range of 1130 to 1070 ° C. in the temperature drop distribution of the silicon single crystal ingot. 1130-10
Even if the temperature decrease rate at 70 ° C exceeds 0.3 ° C / minute, the temperature range in which the temperature decrease rate is reduced to 0 to 0.3 ° C / minute is 113.
If the temperature exceeds 0 ° C. or is lower than 1070 ° C., it is not possible to sufficiently suppress the generation of stacking faults and oxygen precipitates in the silicon wafer when the silicon single crystal ingot is pulled and then heat-treated. The temperature range is 1120 to 10
80 ° C. is more preferable. Further, the temperature decrease rate of 0 ° C./min means that the temperature decrease is stopped and maintained at the corresponding temperature. Further, the holding time of the temperature decreasing rate is at least 10 minutes, preferably 10 minutes or more and 15 hours. From the viewpoint of improving productivity and energy consumption, 10 minutes or more and less than 3 hours is more preferable, and 1 hour or more and 2 hours or less is further preferable.

【0008】[0008]

【作用】0.6〜2.0mm/分の引上げ速度で引上げ
つつあるシリコン単結晶インゴットの降下温度分布のう
ち1130〜1070℃の温度範囲で降温速度を0〜
0.3℃/分に減速して上記降温速度を少なくとも10
分間保持することにより、欠陥発生が著しく抑制される
技術的理由は未だ十分に解明されていないが、次のよう
に推定される。一般に引上げ中のバルク内の微小欠陥
(BMD:bulk micro defect)の核の形成には、格子
間シリコンや空孔などの点欠陥が関与していると考えら
れている。これらの点欠陥は引上げ中に1300℃の高
温で2時間程度保持されると結晶外への拡散と格子間シ
リコンと空孔との対消滅が起こる。これにより点欠陥は
減少し、BMDは形成されなくなると考えられている。
反面これより低温になるほど、これらの点欠陥の拡散は
遅くなるのに加えて過飽和な酸素により複合体が作ら
れ、結果として点欠陥は比較的安定な状態になると考え
られる。本発明の特徴ある1130〜1070℃で降温
を停止するか、或いは極低速で降温することにより11
00℃近傍で保持すると、上記複合体が不安定になり、
格子間シリコンと空孔が結合する対消滅が再び起こって
点欠陥が減少し、その後の低温の熱履歴によっても安定
な核が形成されなくなると考えられる。
In the temperature drop distribution of the silicon single crystal ingot which is being pulled up at a pulling rate of 0.6 to 2.0 mm / min, the temperature lowering rate is 0 to 0 in the temperature range of 1130 to 1070 ° C.
Decelerate to 0.3 ° C / min to reduce the temperature decrease rate to at least 10
The technical reason why the occurrence of defects is remarkably suppressed by holding for a minute is not yet fully understood, but it is presumed as follows. It is generally considered that point defects such as interstitial silicon and vacancies are involved in the formation of nuclei of bulk micro defects (BMD) during pulling. If these point defects are held at a high temperature of 1300 ° C. for about 2 hours during pulling, diffusion out of the crystal and pair annihilation of interstitial silicon and vacancies occur. It is believed that this reduces the point defects and prevents BMD formation.
On the other hand, it is considered that the lower the temperature, the slower the diffusion of these point defects and the formation of a complex by supersaturated oxygen, resulting in the point defects becoming relatively stable. The temperature is stopped at 1130 to 1070 ° C, which is a feature of the present invention, or the temperature is lowered at an extremely low speed.
If kept near 00 ° C, the above complex becomes unstable,
It is considered that the pair annihilation of interstitial silicon and vacancies occurs again and the point defects are reduced, and stable nuclei are not formed by the subsequent low temperature thermal history.

【0009】[0009]

【実施例】次に、本発明の実施例を図面に基づいて詳し
く説明する。 <実施例1>引上げ中のシリコン単結晶インゴットをど
の位の温度領域でその降温速度を遅くすると積層欠陥や
酸素析出物の要因が消滅するか否か調べるために、先
ず、図8に示されるインゴット引上げ装置2で引上げ中
のシリコン単結晶インゴット自体の温度分布を調べた。
このためにこの装置2で育成の終了した直径5インチの
長さ800mmのシリコン単結晶インゴットにその中心
軸と平行に深さ400mmの穴をあけ、穴の中に等間隔
に複数の熱電対を取付けた。この熱電対を取付けたイン
ゴットを引上げ装置2内にセットし、通常の引上げ時の
加熱条件でヒータ6によりシリコン融液を保持したまま
インゴットを加熱した。その後シリコン単結晶インゴッ
トを段階的に下降溶解させながら熱電対で温度を測定し
た。複数の熱電対の検出結果から得られた図8の引上げ
装置2におけるシリコン単結晶インゴット1の温度分布
を図4に示す。図4において、横軸はインゴット1のボ
トム(0mm)からトップ(800mm)に至るまでの
長さ、換言するとシリコン融液表面からの距離を示し、
縦軸はそれぞれの距離に対応するインゴット自体の温度
を示す。
Embodiments of the present invention will now be described in detail with reference to the drawings. <Example 1> First, FIG. 8 is shown in order to investigate in which temperature range the temperature of the silicon single crystal ingot being pulled up slows down the factor of stacking faults and oxygen precipitates. The temperature distribution of the silicon single crystal ingot itself being pulled by the ingot pulling apparatus 2 was examined.
For this reason, a hole having a depth of 400 mm was made in parallel with the central axis of a silicon single crystal ingot having a diameter of 5 inches and a length of 800 mm, which had been grown in the apparatus 2, and a plurality of thermocouples were equally spaced in the hole. I installed it. The ingot to which this thermocouple was attached was set in the pulling device 2, and the ingot was heated by the heater 6 while holding the silicon melt under the normal heating conditions for pulling. Then, the temperature was measured with a thermocouple while gradually melting the silicon single crystal ingot. FIG. 4 shows the temperature distribution of the silicon single crystal ingot 1 in the pulling device 2 of FIG. 8 obtained from the detection results of a plurality of thermocouples. In FIG. 4, the horizontal axis represents the length from the bottom (0 mm) to the top (800 mm) of the ingot 1, in other words, the distance from the silicon melt surface,
The vertical axis represents the temperature of the ingot itself corresponding to each distance.

【0010】図8に示されるインゴット引上げ装置2を
用いて0.6〜0.8mm/分程度の等速で引上げた場
合、シリコンウェーハにしたときにリング状の積層欠陥
が高密度に発生することが分かっているため、この実施
例1及び次の比較例1では0.65mm/分の等速で、
インゴット引上げ装置2を用いて新たにシリコン単結晶
インゴットを引上げたときにリング状の積層欠陥が消滅
するか或いは発生しているかを調べた。即ち、この例で
は装置2で直径5インチのシリコン単結晶インゴットを
0.65mm/分で引上げ、インゴットの定径部の長さ
が450mmとなったところで、ヒータで加熱を続けな
がら引上げを停止し、そこで2時間保持した。その後再
び0.65mm/分の等速で引上げ、直径5インチの長
さ800mmのシリコン単結晶インゴット1を育成し
た。育成の終了したリコン単結晶インゴットを装置2か
ら取出し、インゴット中心でその引上げ方向に平行にス
ライスし、そのスライスしたサンプルの半分を湿潤酸素
(wetO2)雰囲気中、1100℃で1時間熱処理し
てサンプルA1を得た。また残りの半分を乾燥酸素(d
ryO2)雰囲気中、1000℃で40時間熱処理して
別のサンプルB1を得た。
When the ingot pulling apparatus 2 shown in FIG. 8 is used to pull at a constant velocity of about 0.6 to 0.8 mm / min, ring-shaped stacking faults occur at a high density when formed into a silicon wafer. Since it is known that in Example 1 and Comparative Example 1 below, at a constant velocity of 0.65 mm / min,
It was examined whether a ring-shaped stacking fault disappeared or occurred when a silicon single crystal ingot was newly pulled by using the ingot pulling apparatus 2. That is, in this example, a silicon single crystal ingot having a diameter of 5 inches was pulled at 0.65 mm / min in the apparatus 2, and when the length of the constant diameter portion of the ingot reached 450 mm, pulling was stopped while continuing heating with the heater. , Held there for 2 hours. Then, the silicon single crystal ingot 1 having a diameter of 5 inches and a length of 800 mm was grown again at a constant rate of 0.65 mm / min. The grown recon single crystal ingot is taken out from the apparatus 2, sliced in parallel to the pulling direction at the center of the ingot, and half of the sliced sample is heat-treated at 1100 ° C. for 1 hour in a wet oxygen (wetO 2 ) atmosphere. Sample A1 was obtained. The other half is dry oxygen (d
Another sample B1 was obtained by heat treatment at 1000 ° C. for 40 hours in a ryO 2 ) atmosphere.

【0011】<比較例1>実施例1と同じ図8に示され
る引上げ装置2を用いて、シリコン単結晶インゴットを
途中で引上げを停止せずに、0.65mm/分の等速で
引上げた。育成の終了した直径5インチの長さ800m
mのシリコン単結晶インゴット1を装置2より取出し、
以下実施例1と同様にインゴット中心でその引上げ方向
に平行にスライスし、そのスライスしたサンプルの半分
を湿潤酸素(wetO2)雰囲気中、1100℃で1時
間熱処理してサンプルA1’を得た。また残り半分を実
施例1と同様に乾燥酸素(dryO2)雰囲気中、10
00℃で40時間熱処理して別のサンプルB1’を得
た。このインゴット全体を0.65mm/分の等速で引
上げたときのインゴットが受ける熱履歴を図6に示す。
図6は図4の横軸の距離を引上げ速度0.65mm/分
で除算し、引上げ時間を横軸としたものである。
<Comparative Example 1> A silicon single crystal ingot was pulled at a constant velocity of 0.65 mm / min using the pulling apparatus 2 shown in FIG. . 800m long with a diameter of 5 inches
Take out the silicon single crystal ingot 1 of m from the device 2,
Then, in the same manner as in Example 1, a slice was sliced parallel to the pulling direction at the center of the ingot, and half of the sliced sample was heat-treated at 1100 ° C. for 1 hour in a wet oxygen (wetO 2 ) atmosphere to obtain a sample A1 ′. The remaining half was subjected to 10 in the dry oxygen (dryO 2 ) atmosphere as in Example 1.
Another sample B1 ′ was obtained by heat treatment at 00 ° C. for 40 hours. FIG. 6 shows the heat history of the ingot when the whole ingot is pulled at a constant speed of 0.65 mm / min.
In FIG. 6, the distance on the horizontal axis of FIG. 4 is divided by the pulling speed of 0.65 mm / min, and the pulling time is plotted on the horizontal axis.

【0012】<比較試験1及びその評価> 積層欠陥の発生状況の観察 実施例1のサンプルA1と、比較例1のサンプルA1’の
スライス面を積層欠陥に選択性のあるエッチング液で処
理した後、目視及び光学顕微鏡により観察した。実施例
1の接写写真図を図1の(a-1)に、比較例1の接写写
真図を図2の(a-2)にそれぞれ示す。図1に示す温度
は引上げを停止し、2時間保持したときのインゴットの
部位別の温度である。両図において白く筋状に現れた部
分が積層欠陥である。比較例1では積層欠陥がインゴッ
トの周縁近傍にインゴットのほぼ全長にわたって現れて
いた。これはシリコンウェーハの形状で観察するとリン
グ状に分布しているので、リング状の積層欠陥(リング
OSF)と呼ばれている。この比較例1に対して、実施
例1では1100℃近傍の領域で積層欠陥が消滅し、他
の温度領域では積層欠陥が現れていた。
<Comparative Test 1 and Evaluation> Observation of Occurrence of Stacking Faults After the slice planes of the sample A1 of Example 1 and the sample A1 ′ of Comparative Example 1 were treated with an etchant having selectivity for stacking faults. It was observed visually and by an optical microscope. A close-up photograph of Example 1 is shown in (a-1) of FIG. 1, and a close-up photograph of Comparative Example 1 is shown in (a-2) of FIG. The temperature shown in FIG. 1 is the temperature of each part of the ingot when pulling is stopped and the pulling is held for 2 hours. The white stripes in both figures are stacking faults. In Comparative Example 1, stacking faults appeared near the periphery of the ingot over substantially the entire length of the ingot. This is called a ring-shaped stacking fault (ring OSF) because it is distributed in a ring shape when observed in the shape of a silicon wafer. In contrast to Comparative Example 1, in Example 1, the stacking fault disappeared in the region near 1100 ° C., and the stacking fault appeared in other temperature regions.

【0013】 酸素析出物の発生状況の観察 実施例1のサンプルB1と、比較例1のサンプルB1’の
スライス面を酸素析出物に選択性のあるエッチング液で
スライス面を処理した後、目視及び光学顕微鏡により観
察した。実施例1の接写写真図を図1の(b-1)に、比
較例1の接写写真図を図2の(b-2)にそれぞれ示す。
両図において白い部分が酸素析出物が高密度に発生して
いる領域である。比較例1では酸素析出物がインゴット
の全長にわたって現れていたのに対して、実施例1では
1100℃近傍の領域で酸素析出物が消滅し、他の温度
領域では酸素析出物が現れていた。
Observation of Occurrence of Oxygen Precipitate Sample B1 of Example 1 and sample B1 ′ of Comparative Example 1 were sliced with an etching solution having selectivity for oxygen precipitates, and then visually and It was observed with an optical microscope. A close-up photograph of Example 1 is shown in FIG. 1 (b-1), and a close-up photograph of Comparative Example 1 is shown in FIG. 2 (b-2).
In both figures, the white part is the region where oxygen precipitates are generated at high density. In Comparative Example 1, the oxygen precipitates appeared over the entire length of the ingot, whereas in Example 1, the oxygen precipitates disappeared in the region near 1100 ° C., and the oxygen precipitates appeared in other temperature regions.

【0014】<実施例2〜10>実施例1及び比較例1
の結果から、1100℃近傍の温度領域で積層欠陥及び
酸素析出物が消滅することが判ったので、図7に示され
るインゴット引上げ装置12を用いて直径5インチの長
さ800mmのシリコン単結晶インゴット11を0.6
5mm/分の等速の引上げ速度で引上げた。図7におい
て、図8に示した構成要素と同一の構成要素には同一の
符号を付している。図7に示される引上げ装置12の特
徴ある構成は、引上げつつあるシリコン単結晶インゴッ
ト11の温度が1130℃、1100℃、1070℃と
なる位置から上方の所定の帯域に温度制御装置として補
助ヒータ10をそれぞれ設けたことにある。この補助ヒ
ータ10によって降温速度を制御した。この例では、1
130℃、1100℃、1070℃でそれぞれ降温速度
0℃/分となって降温を停止するように、またそれぞれ
の温度での停止時間が10分間、1時間又は2時間とそ
れぞれなる(保持時間が10分間、1時間又は2時間に
なる)ように、補助ヒータ10の加熱量及びその長さL
を調整して設けた。具体的には停止時間が10分間のと
きには補助ヒータ10の長さLを最短にし、2時間のと
きには最長にした。また保持温度が1130℃のときに
は補助ヒータ10の加熱量を最大にし、1070℃のと
きには最小にした。
<Examples 2 to 10> Example 1 and Comparative Example 1
From the results, it was found that stacking faults and oxygen precipitates disappeared in a temperature range near 1100 ° C. Therefore, using the ingot pulling device 12 shown in FIG. 7, a silicon single crystal ingot having a diameter of 5 inches and a length of 800 mm was used. 11 to 0.6
It was pulled up at a constant pulling speed of 5 mm / min. 7, the same components as those shown in FIG. 8 are designated by the same reference numerals. A characteristic configuration of the pulling device 12 shown in FIG. 7 is that the temperature of the silicon single crystal ingot 11 being pulled is 1130 ° C., 1100 ° C., and 1070 ° C. The auxiliary heater 10 as a temperature control device is provided in a predetermined zone above the position. Have been established respectively. The temperature decrease rate was controlled by the auxiliary heater 10. In this example, 1
At 130 ° C., 1100 ° C., 1070 ° C., the temperature decreasing rate becomes 0 ° C./min to stop the temperature decrease, and the stopping time at each temperature is 10 minutes, 1 hour or 2 hours (holding time 10 minutes, 1 hour or 2 hours) so that the heating amount of the auxiliary heater 10 and its length L
Was adjusted and provided. Specifically, the length L of the auxiliary heater 10 was set to the shortest when the stop time was 10 minutes, and set to the longest when the stop time was 2 hours. When the holding temperature was 1130 ° C, the heating amount of the auxiliary heater 10 was maximized, and when it was 1070 ° C, it was minimized.

【0015】実施例6の停止時間が1時間で保持温度が
1100℃となるように補助ヒータ10を調整したとき
の図7に示されるインゴット引上げ装置12におけるシ
リコン単結晶インゴットの温度分布を図3に示す。この
温度分布も図4と同様にして得られた。この実施例6の
インゴット全体を0.65mm/分の等速で引上げたと
きのインゴットの熱履歴を図5に示す。図5は図3の横
軸の距離を引上げ速度0.65mm/分で除算し、引上
げ時間を横軸としたものである。育成の終了したシリコ
ン単結晶インゴットを装置12から取出し、実施例1と
同様にインゴット中心でその引上げ方向に平行にスライ
スし、そのスライスしたサンプルの半分を湿潤酸素(w
etO2)雰囲気中、1100℃で1時間熱処理して9
枚のサンプルA2〜A10を得た。また残り半分を実施例
1と同様に乾燥酸素(dryO2)雰囲気中、1000
℃で40時間熱処理して別の9枚のサンプルB2〜B10
を得た。
FIG. 3 shows the temperature distribution of the silicon single crystal ingot in the ingot pulling apparatus 12 shown in FIG. 7 when the auxiliary heater 10 was adjusted so that the holding temperature was 1100 ° C. with the stop time of 1 hour in Example 6. Shown in. This temperature distribution was also obtained in the same manner as in FIG. FIG. 5 shows the heat history of the ingot when the entire ingot of Example 6 was pulled at a constant speed of 0.65 mm / min. In FIG. 5, the distance on the horizontal axis of FIG. 3 is divided by the pulling speed of 0.65 mm / min, and the pulling time is plotted on the horizontal axis. The grown silicon single crystal ingot is taken out from the apparatus 12, sliced in the center of the ingot in parallel with the pulling direction in the same manner as in Example 1, and half of the sliced sample is wet oxygen (w).
EtO 2 ) atmosphere for 1 hour at 1100 ° C. for 9 hours
Samples A2 to A10 were obtained. The other half was subjected to the same procedure as in Example 1 in a dry oxygen (dryO 2 ) atmosphere to 1000
Another 9 samples B2 to B10 after heat treatment at ℃ for 40 hours
Got

【0016】<比較例2〜9>1000℃、1050
℃、1200℃でそれぞれ降温速度0℃/分となって降
温を停止するように、またそれぞれの温度での停止時間
が10分間、1時間又は2時間とそれぞれなる(保持時
間が10分間、1時間又は2時間になる)ように、図7
に示すインゴット引上げ装置12の補助ヒータ10の加
熱量及びその長さLを調整して設けた。この調整の仕方
は実施例2〜10と同様である。その他は実施例2と同
様に引上げてシリコン単結晶インゴットを得た。育成の
終了したシリコン単結晶インゴットを装置12から取出
し、実施例1と同様にインゴット中心でその引上げ方向
に平行にスライスし、そのスライスしたサンプルの半分
を湿潤酸素(wetO2)雰囲気中、1100℃で1時
間熱処理して8枚のサンプルA2’〜A9’を得た。また
残り半分を実施例1と同様に乾燥酸素(dryO2)雰
囲気中、1000℃で40時間熱処理して別の8枚のサ
ンプルB2’〜B9’を得た。
<Comparative Examples 2 to 9> 1000 ° C., 1050
At a temperature decrease rate of 0 ° C./min at 100 ° C. and 1200 ° C. to stop the temperature decrease, and the stop time at each temperature is 10 minutes, 1 hour or 2 hours, respectively (holding time is 10 minutes, 1 hour). As shown in FIG.
The heating amount and the length L of the auxiliary heater 10 of the ingot pulling device 12 shown in FIG. The method of this adjustment is the same as in Examples 2-10. Others were pulled up in the same manner as in Example 2 to obtain a silicon single crystal ingot. The grown silicon single crystal ingot is taken out from the apparatus 12, sliced parallel to the pulling direction at the center of the ingot as in Example 1, and half of the sliced sample is placed at 1100 ° C. in a wet oxygen (wetO 2 ) atmosphere. Then, heat treatment was performed for 1 hour to obtain eight samples A2 'to A9'. The other half was heat-treated at 1000 ° C. for 40 hours in a dry oxygen (dryO 2 ) atmosphere in the same manner as in Example 1 to obtain another eight samples B2 ′ to B9 ′.

【0017】<比較試験2及びその評価> 積層欠陥密度の測定 実施例2〜10のサンプルA2〜A10と、比較例1のサ
ンプルA1’と、比較例2〜9のサンプルA2’〜A9’
を積層欠陥に選択性のあるエッチング液でそれぞれ処理
した後、任意の箇所を光学顕微鏡で観察して1cm3
りの積層欠陥数(積層欠陥密度)を測定した。その結果
を表1に示す。
<Comparative Test 2 and Evaluation> Measurement of Stacking Fault Density Samples A2 to A10 of Examples 2 to 10, Sample A1 'of Comparative Example 1 and Samples A2' to A9 'of Comparative Examples 2 to 9
Was treated with an etching liquid having selectivity for stacking faults, and an arbitrary portion was observed with an optical microscope to measure the number of stacking faults per 1 cm 3 (stacking fault density). The results are shown in Table 1.

【0018】 酸素析出物密度の測定 実施例2〜10のサンプルB2〜B10と、比較例1のサ
ンプルB1’と、比較例2〜9のサンプルB2’〜B9’
を酸素析出物に選択性のあるエッチング液で処理した
後、任意の箇所を光学顕微鏡で観察して1cm3当りの
酸素析出物数(酸素析出物密度)を測定した。その結果
を表1に示す。
Measurement of oxygen precipitate density Samples B2 to B10 of Examples 2 to 10, sample B1 ′ of Comparative Example 1 and samples B2 ′ to B9 ′ of Comparative Examples 2 to 9
Was treated with an etchant having selectivity for oxygen precipitates, and then an arbitrary portion was observed with an optical microscope to measure the number of oxygen precipitates per 1 cm 3 (oxygen precipitate density). The results are shown in Table 1.

【0019】[0019]

【表1】 [Table 1]

【0020】表1から明らかなように、比較例1〜9の
積層欠陥密度は15.0〜48.0×106/cm3であ
るのに対して、実施例2〜10の積層欠陥密度は0〜
1.6×106/cm3であり、極めて小さかった。更に
比較例1の酸素析出物密度が600〜900×106
cm3であって、比較例2〜9の酸素析出物密度が2
2.0〜360.0×106/cm3であるのに対して、
実施例2〜10の酸素析出物密度は0〜22.0×10
6/cm3であり、極めて小さかった。
As is clear from Table 1, the stacking fault densities of Comparative Examples 1 to 9 are 15.0 to 48.0 × 10 6 / cm 3 , whereas the stacking fault densities of Examples 2 to 10 are Is 0
It was 1.6 × 10 6 / cm 3 , which was extremely small. Furthermore, the oxygen precipitate density of Comparative Example 1 is 600 to 900 × 10 6 /
cm 3 and the density of oxygen precipitates in Comparative Examples 2 to 9 was 2
While it is 2.0 to 360.0 × 10 6 / cm 3 ,
The oxygen precipitate density of Examples 2-10 is 0-22.0x10.
It was 6 / cm 3 , which was extremely small.

【0021】[0021]

【発明の効果】以上述べたように、本発明のシリコン単
結晶の引上げ方法によれば、0.6〜2.0mm/分の
引上げ速度で引上げつつあるシリコン単結晶インゴット
の降下温度分布のうち1130〜1070℃の温度範囲
で降温速度を0〜0.3℃/分に減速して上記降温速度
を少なくとも10分間保持することにより、半導体デバ
イス工程で熱処理したときにシリコンウェーハに積層欠
陥及び酸素析出物を生じさせないようにすることができ
る。この結果、得られたシリコン単結晶インゴットから
製造されたシリコン単結晶ウェーハは、欠陥の発生が著
しく低くなり工業上の利用価値が極めて大きい優れた効
果を奏する。また、本発明の方法は、酸素析出物や積層
欠陥のもととなる核の発生を抑制する引上げ速度が0.
4mm/分の従来の方法より速いため、生産性が高く、
エネルギ消費が少なくて済む利点もある。
As described above, according to the method for pulling a silicon single crystal of the present invention, of the temperature drop distribution of the silicon single crystal ingot which is being pulled at a pulling rate of 0.6 to 2.0 mm / min. By decelerating the temperature lowering rate to 0 to 0.3 ° C./min in the temperature range of 1130 to 1070 ° C. and maintaining the temperature lowering rate for at least 10 minutes, stacking faults and oxygen are formed on the silicon wafer when heat-treated in the semiconductor device process. It is possible to prevent the formation of precipitates. As a result, the silicon single crystal wafer manufactured from the obtained silicon single crystal ingot has an excellent effect that the generation of defects is significantly reduced and the industrial utility value is extremely large. Further, in the method of the present invention, the pulling rate that suppresses the generation of nuclei that are the origin of oxygen precipitates and stacking faults is 0.
Since it is faster than the conventional method of 4 mm / min, productivity is high,
There is also an advantage that it consumes less energy.

【図面の簡単な説明】[Brief description of drawings]

【図1】本発明実施例1のシリコン単結晶インゴットを
引上げた後、熱処理したときの積層欠陥と酸素析出物の
発生状況を示すインゴットスライス面における結晶構造
を接写した写真図。
FIG. 1 is a close-up photograph of a crystal structure on an ingot slice plane showing a stacking fault and an occurrence of oxygen precipitates when a silicon single crystal ingot of Example 1 of the present invention is pulled and then heat treated.

【図2】比較例1のシリコン単結晶インゴットを引上げ
た後、熱処理したときの積層欠陥と酸素析出物の発生状
況を示すインゴットスライス面における結晶構造を接写
した写真図。
FIG. 2 is a photograph showing a close-up of a crystal structure on an ingot slice plane showing a stacking fault and an occurrence of oxygen precipitates when a silicon single crystal ingot of Comparative Example 1 is pulled and then heat treated.

【図3】図7に示されるインゴット引上げ装置における
本発明実施例6のシリコン単結晶インゴット引上げ時の
温度分布図。
FIG. 3 is a temperature distribution diagram when pulling a silicon single crystal ingot of Example 6 of the present invention in the ingot pulling apparatus shown in FIG. 7.

【図4】図8に示されるインゴット引上げ装置における
比較例1のシリコン単結晶インゴット引上げ時の温度分
布図。
4 is a temperature distribution diagram when pulling a silicon single crystal ingot of Comparative Example 1 in the ingot pulling apparatus shown in FIG.

【図5】図7に示されるインゴット引上げ装置で0.6
5mm/分の等速で引上げたときの実施例6のシリコン
単結晶インゴットの温度分布図。
FIG. 5 shows the ingot pulling device shown in FIG.
The temperature distribution figure of the silicon single crystal ingot of Example 6 when pulled up at a constant speed of 5 mm / min.

【図6】図8に示されるインゴット引上げ装置で0.6
5mm/分の等速で引上げたときの比較例1のシリコン
単結晶インゴットの温度分布図。
FIG. 6 shows the ingot pulling device shown in FIG.
FIG. 5 is a temperature distribution diagram of the silicon single crystal ingot of Comparative Example 1 when pulled at a constant speed of 5 mm / min.

【図7】本発明実施例2〜10及び比較例2〜9のシリ
コン単結晶インゴットの育成に用いた引上げ装置の構成
図。
FIG. 7 is a configuration diagram of a pulling apparatus used for growing the silicon single crystal ingots of Examples 2 to 10 of the present invention and Comparative Examples 2 to 9.

【図8】実施例1及び比較例1のシリコン単結晶インゴ
ットの育成に用いた引上げ装置の構成図。
8 is a configuration diagram of a pulling apparatus used for growing the silicon single crystal ingots of Example 1 and Comparative Example 1. FIG.

【符号の説明】[Explanation of symbols]

1,11 シリコン単結晶インゴット 2,12 インゴット引上げ装置 4 石英坩堝 6 ヒータ 7 シリコン融液 10 補助ヒータ 1,11 Silicon single crystal ingot 2,12 Ingot pulling device 4 Quartz crucible 6 Heater 7 Silicon melt 10 Auxiliary heater

─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───

【手続補正書】[Procedure amendment]

【提出日】平成6年9月19日[Submission date] September 19, 1994

【手続補正1】[Procedure Amendment 1]

【補正対象書類名】図面[Document name to be corrected] Drawing

【補正対象項目名】図1[Name of item to be corrected] Figure 1

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【図1】 FIG.

【手続補正2】[Procedure Amendment 2]

【補正対象書類名】図面[Document name to be corrected] Drawing

【補正対象項目名】図2[Name of item to be corrected] Figure 2

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【図2】 [Fig. 2]

【手続補正3】[Procedure 3]

【補正対象書類名】明細書[Document name to be amended] Statement

【補正対象項目名】0018[Correction target item name] 0018

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【0018】 酸素析出物密度の測定 実施例2〜10のサンプルB2〜B10と、比較例1の
サンプルB1’と、比較例2〜9のサンプルB2’〜B
9’を酸素析出物に選択性のあるエッチング液で処理し
た後、任意の箇所を光学顕微鏡で観察して1cm当り
の酸素析出物数(酸素析出物密度)を測定した。その結
果を表1に示す。
[0018] Measurement of Oxygen Precipitant Density Samples B2 to B10 of Examples 2 to 10 and Comparative Example 1
Sample B1 'and samples B2' to B of Comparative Examples 2 to 9
9'is treated with an etchant that is selective for oxygen precipitates.
After observing, 1cm by observing any part with an optical microscopeThreeHit
The number of oxygen precipitates (oxygen precipitate density) was measured. That conclusion
The results are shown in Table 1.

───────────────────────────────────────────────────── フロントページの続き (72)発明者 渡辺 敏彦 埼玉県大宮市北袋町1丁目297番地 三菱 マテリアル株式会社中央研究所内 (72)発明者 降屋 久 埼玉県大宮市北袋町1丁目297番地 三菱 マテリアル株式会社中央研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshihiko Watanabe 1-297 Kitabukuro-cho, Omiya-shi, Saitama Prefecture Central Research Laboratory, Mitsubishi Materials Corporation (72) Hisashi Furuya 1-297 Kitabukuro-cho, Omiya-shi, Saitama Mitsubishi Central Research Laboratory, Materials Co., Ltd.

Claims (2)

【特許請求の範囲】[Claims] 【請求項1】 引上げ装置(12)内の坩堝(4)に保持され
たシリコン融液(7)からシリコン単結晶インゴット(11)
を引上げる方法において、 0.6〜2.0mm/分の引上げ速度で引上げつつある
シリコン単結晶インゴット(11)の降下温度分布のうち1
130〜1070℃の温度範囲で降温速度を0〜0.3
℃/分に減速して前記降温速度を少なくとも10分間保
持することにより引上げ後熱処理したときにシリコンウ
ェーハに積層欠陥及び酸素析出物を生じさせないように
することを特徴とするシリコン単結晶の引上げ方法。
1. A silicon single crystal ingot (11) formed from a silicon melt (7) held in a crucible (4) in a pulling device (12).
In the method of pulling up silicon, one of the temperature drop distributions of the silicon single crystal ingot (11) being pulled up at a pulling rate of 0.6 to 2.0 mm / min.
In the temperature range of 130 to 1070 ° C, the temperature decreasing rate is 0 to 0.3.
A method for pulling up a silicon single crystal, which is characterized in that a stacking fault and an oxygen precipitate are not generated in a silicon wafer when heat-treated after pulling by decelerating to ° C / min and maintaining the temperature lowering rate for at least 10 minutes. .
【請求項2】 1130〜1070℃の温度範囲での降
温速度の保持時間が10分間以上3時間未満である請求
項1記載のシリコン単結晶の引上げ方法。
2. The method for pulling a silicon single crystal according to claim 1, wherein the holding time of the temperature lowering rate in the temperature range of 1130 to 1070 ° C. is 10 minutes or more and less than 3 hours.
JP22195294A 1994-09-16 1994-09-16 Silicon single crystal pulling method Expired - Lifetime JP3149320B2 (en)

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Application Number Priority Date Filing Date Title
JP22195294A JP3149320B2 (en) 1994-09-16 1994-09-16 Silicon single crystal pulling method

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Publication Number Publication Date
JPH0891983A true JPH0891983A (en) 1996-04-09
JP3149320B2 JP3149320B2 (en) 2001-03-26

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Country Link
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6548886B1 (en) 1998-05-01 2003-04-15 Wacker Nsce Corporation Silicon semiconductor wafer and method for producing the same
US7125608B2 (en) 2003-12-03 2006-10-24 Siltron Inc. Single-crystal silicon ingot and wafer having homogeneous vacancy defects, and method and apparatus for making same

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US7125608B2 (en) 2003-12-03 2006-10-24 Siltron Inc. Single-crystal silicon ingot and wafer having homogeneous vacancy defects, and method and apparatus for making same

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