JP7666396B2 - Method for detecting crystal defects in silicon single crystal substrate - Google Patents
Method for detecting crystal defects in silicon single crystal substrate Download PDFInfo
- Publication number
- JP7666396B2 JP7666396B2 JP2022079085A JP2022079085A JP7666396B2 JP 7666396 B2 JP7666396 B2 JP 7666396B2 JP 2022079085 A JP2022079085 A JP 2022079085A JP 2022079085 A JP2022079085 A JP 2022079085A JP 7666396 B2 JP7666396 B2 JP 7666396B2
- Authority
- JP
- Japan
- Prior art keywords
- silicon single
- single crystal
- heat treatment
- crystal substrate
- defects
- 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.)
- Active
Links
Images
Landscapes
- Sampling And Sample Adjustment (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Testing Or Measuring Of Semiconductors Or The Like (AREA)
Description
本発明は、シリコン単結晶基板に存在する結晶欠陥を熱処理を行うことにより高感度に検出する方法に関する。 The present invention relates to a method for detecting crystal defects present in a silicon single crystal substrate with high sensitivity by performing a heat treatment.
近年、半導体素子の微細化、高集積化に伴い、半導体結晶に存在する結晶欠陥の正確な評価はより重要になっている。
半導体シリコン結晶において、空孔形成が優勢の領域においては、Ｖｏｉｄ、酸素析出物が主たる結晶欠陥であり、格子間シリコン形成が優勢の領域においては、ＳＦ（Ｓｔａｃｋｉｎｇ Ｆａｕｌｔ）、転位ループが主たる結晶欠陥であることが広く知られている。
これらの結晶欠陥は、デバイスの歩留まりやゲッタリング能力に影響を及ぼすことが広く知られており、これらの結晶欠陥の形成を制御し、製造された結晶にどれだけ存在しているのかを正確に把握する必要がある。
In recent years, with the miniaturization and high integration of semiconductor elements, accurate evaluation of crystal defects existing in semiconductor crystals has become more important.
It is widely known that in semiconductor silicon crystals, in regions where vacancy formation is predominant, voids and oxygen precipitates are the main crystal defects, while in regions where interstitial silicon formation is predominant, SFs (Stacking Faults) and dislocation loops are the main crystal defects.
These crystal defects are widely known to affect device yields and gettering capabilities, and it is therefore necessary to control the formation of these crystal defects and accurately understand their presence in the manufactured crystals.
上記結晶欠陥を高感度に検出する手法として、特許文献１には、半導体単結晶基板を水素雰囲気下で８００－１１００℃で熱処理することで、結晶欠陥を顕在化する技術が開示されている。
また、特許文献２には、半導体基板の表面を、水素雰囲気下で９００－１２５０℃で熱処理した後、塩化水素、臭化水素、ヨウ化水素、及び、これらの組み合わせからなる群から選択された気体のエッチャントを含む還元性雰囲気にさらし、８００－１１００℃で欠陥を顕在化する技術が開示されている。
As a method for detecting the above crystal defects with high sensitivity, Patent Document 1 discloses a technique for making crystal defects visible by heat treating a semiconductor single crystal substrate at 800-1100° C. in a hydrogen atmosphere.
Furthermore, Patent Document 2 discloses a technique in which the surface of a semiconductor substrate is heat-treated at 900-1250°C in a hydrogen atmosphere, and then exposed to a reducing atmosphere containing a gaseous etchant selected from the group consisting of hydrogen chloride, hydrogen bromide, hydrogen iodide, and combinations thereof, and defects are made visible at 800-1100°C.
上記特許文献１の技術は、水素雰囲気で熱処理することで結晶欠陥を顕在化する技術であるが、基板の水準によっては表面欠陥が消失し欠陥を顕在化できない。
また、上記特許文献２の技術は、水素雰囲気下の熱処理後に還元性雰囲気下で熱処理することで欠陥を顕在化する技術であるが、基板の酸素濃度によっては欠陥が溶体化してしまい、特に酸素濃度が１．２ｐｐｍａ未満の低酸素結晶には適用できない。
The technique of the above-mentioned Patent Document 1 is a technique for making crystal defects visible by heat treatment in a hydrogen atmosphere, but depending on the level of the substrate, surface defects may disappear and the defects may not be made visible.
In addition, the technology of Patent Document 2 is a technology in which defects are made visible by performing heat treatment in a reducing atmosphere after heat treatment in a hydrogen atmosphere. However, depending on the oxygen concentration of the substrate, the defects may go into solution, and the technology is not applicable to low-oxygen crystals, particularly those with an oxygen concentration of less than 1.2 ppma.
本発明の目的は、たとえ低酸素濃度のシリコン単結晶基板であっても効果的に結晶欠陥を顕在化して検出する方法を提供することにある。 The object of the present invention is to provide a method for effectively revealing and detecting crystal defects even in silicon single crystal substrates with low oxygen concentrations.
上記目的を達成するために、本発明は、シリコン単結晶基板に熱処理を施し、該シリコン単結晶基板に存在する結晶欠陥を検出する方法であって、
前記シリコン単結晶基板の酸素濃度を測定する工程Ａと、
前記測定したシリコン単結晶基板の酸素濃度から酸素の固溶限界温度を求める工程Ｂと、
前記シリコン単結晶基板に施す前記熱処理の熱処理温度を８００℃以上、かつ前記求めた酸素の固溶限界温度未満の温度の範囲に決定する工程Ｃと、
前記シリコン単結晶基板を、水素と塩化水素とを含む雰囲気下で、前記決定した熱処理温度で前記熱処理を施す工程Ｄと、
前記熱処理を施したシリコン単結晶基板の表面に顕在化した結晶欠陥の検出を行う工程Ｅと、
を含むことを特徴とするシリコン単結晶基板の結晶欠陥の検出方法を提供する。
In order to achieve the above object, the present invention provides a method for detecting crystal defects present in a silicon single crystal substrate by subjecting the silicon single crystal substrate to a heat treatment, the method comprising the steps of:
A step A of measuring an oxygen concentration of the silicon single crystal substrate;
A step B of determining a solid solubility limit temperature of oxygen from the oxygen concentration of the silicon single crystal substrate measured;
A step C of determining a heat treatment temperature of the heat treatment to be performed on the silicon single crystal substrate to be in a range of 800° C. or higher and lower than the determined solid solubility limit temperature of oxygen;
A step D of subjecting the silicon single crystal substrate to the heat treatment at the determined heat treatment temperature in an atmosphere containing hydrogen and hydrogen chloride;
A step E of detecting crystal defects that have become apparent on the surface of the heat-treated silicon single crystal substrate;
The present invention provides a method for detecting crystal defects in a silicon single crystal substrate, comprising:
このような本発明の検出方法であれば、酸素濃度（格子間酸素濃度）が低いシリコン単結晶基板に対しても、結晶欠陥を効果的に顕在化することができる。このため高感度で結晶欠陥を検出することができる。
熱処理温度を８００℃以上とすることにより短時間の熱処理で効率良く結晶欠陥を顕在化することができる。また、固溶限界温度未満とすることにより、特に低酸素濃度の場合に熱処理温度が固溶限界温度と比較して高いために結晶欠陥が容体化するのを防ぐことができる。そのため結晶欠陥を確実に顕在化することができる。
また、水素と塩化水素を含む雰囲気下での熱処理のため、シリコン単結晶基板の欠陥の部分と無欠陥の部分でのエッチング速度に違いが生じ、それによって結晶欠陥を顕在化することができる。
The detection method of the present invention can effectively reveal crystal defects even in silicon single crystal substrates with a low oxygen concentration (interstitial oxygen concentration), making it possible to detect crystal defects with high sensitivity.
By setting the heat treatment temperature at 800° C. or higher, it is possible to efficiently expose crystal defects with a short heat treatment time. In addition, by setting the heat treatment temperature below the solubility limit temperature, it is possible to prevent crystal defects from becoming solution-like, which would occur when the heat treatment temperature is higher than the solubility limit temperature, particularly in the case of a low oxygen concentration. Therefore, it is possible to reliably expose crystal defects.
Furthermore, because the heat treatment is performed in an atmosphere containing hydrogen and hydrogen chloride, a difference occurs in the etching rate between defective and non-defective portions of the silicon single crystal substrate, which can make crystal defects more apparent.
このとき、前記シリコン単結晶基板の酸素濃度を０．４６ｐｐｍａより大とすることができる。 At this time, the oxygen concentration of the silicon single crystal substrate can be made greater than 0.46 ppma.
このように０．４６ｐｐｍａ付近の極めて低い酸素濃度の場合であっても、本発明の検出方法は結晶欠陥を顕在化して検出可能である。
なお、本願明細書における酸素濃度の値はＪＥＩＴＡ規格によるものである。
Even in the case of an extremely low oxygen concentration of around 0.46 ppma, the detection method of the present invention is capable of revealing and detecting crystal defects.
In addition, the oxygen concentration values in this specification are based on the JEITA standard.
また、前記工程Ｄにおいて複数の前記シリコン単結晶基板に同時に前記熱処理を施す場合、
前記工程Ｂで求める前記酸素の固溶限界温度を、前記複数のシリコン単結晶基板のうち最も低い酸素濃度から求めることができる。
In addition, when the heat treatment is performed simultaneously on a plurality of the silicon single crystal substrates in the step D,
The solubility limit temperature of oxygen determined in the step B can be determined from the lowest oxygen concentration among the plurality of silicon single crystal substrates.
このようにすれば、複数のシリコン単結晶基板について同時の熱処理で結晶欠陥を顕在化して検出することができるので簡便であるし、効率的である。 This method is simple and efficient, since it allows simultaneous heat treatment of multiple silicon single crystal substrates to reveal and detect crystal defects.
また、前記工程Ｄにおいて前記熱処理を施すとき、前記シリコン単結晶基板の表面を鏡面研磨した後、洗浄を行ってから施すことができる。 In addition, when the heat treatment is performed in step D, the surface of the silicon single crystal substrate can be mirror-polished and then cleaned before the heat treatment is performed.
このようにすれば、シリコン単結晶基板表面付近の金属不純物やパーティクルなどの異物を除去することができるため、結晶欠陥のみを顕在化することができる。 In this way, foreign matter such as metal impurities and particles near the surface of the silicon single crystal substrate can be removed, making only the crystal defects visible.
また、前記工程Ｅにおける前記顕在化した結晶欠陥の検出を、表面欠陥検出装置及び走査型電子顕微鏡のうち少なくとも１つを用いて行うことができる。 In addition, the detection of the crystal defects that have become apparent in step E can be performed using at least one of a surface defect detection device and a scanning electron microscope.
このようにすれば、表面欠陥検査装置での検出によって、結晶欠陥密度や分布を短時間で正確に評価することができる。また、走査型電子顕微鏡での検出によって、結晶欠陥の形状、サイズ、組成、結晶欠陥密度等の評価をすることができる。 In this way, the density and distribution of crystal defects can be evaluated accurately in a short time by detection with a surface defect inspection device. In addition, the shape, size, composition, and density of crystal defects can be evaluated by detection with a scanning electron microscope.
本発明のシリコン単結晶基板の結晶欠陥の検出方法であれば、従来法では顕在化できない程の低酸素濃度のシリコン単結晶基板の場合であっても、結晶欠陥を確実に顕在化し、検出することが可能になる。 The method for detecting crystal defects in silicon single crystal substrates of the present invention makes it possible to reliably reveal and detect crystal defects even in silicon single crystal substrates with oxygen concentrations so low that they cannot be detected by conventional methods.
以下、本発明の実施形態について図面を参照して説明するが、本発明はこれに限定されるものではない。
前述したように、特には従来法で結晶欠陥を顕在化できないような低酸素濃度のシリコン単結晶基板であっても、顕在化して検出することができる結晶欠陥の検出方法が求められていた。本発明者が鋭意研究を行ったところ、欠陥検出対象のシリコン単結晶基板に関して測定した酸素濃度から酸素の固溶限界温度を求め、８００℃以上、かつその固溶限界温度未満の温度範囲内で決定した熱処理温度での熱処理（水素と塩化水素を含む雰囲気下）を上記シリコン単結晶基板に施し、それによって顕在化した結晶欠陥を検出する方法であれば、極めて低い酸素濃度のシリコン単結晶基板であっても結晶欠陥を確実に効果的に顕在化することができ、高感度で検出することが可能であることを見出し、本発明を完成させた。
Hereinafter, an embodiment of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.
As described above, there has been a demand for a method for detecting crystal defects that can reveal and detect defects even in silicon single crystal substrates with low oxygen concentrations where crystal defects cannot be revealed by conventional methods. The inventors have conducted intensive research and found that a method for detecting crystal defects that can reveal and detect defects by determining the solubility limit temperature of oxygen from the oxygen concentration measured for a silicon single crystal substrate to be detected, subjecting the silicon single crystal substrate to a heat treatment (in an atmosphere containing hydrogen and hydrogen chloride) at a heat treatment temperature determined within a temperature range of 800°C or higher and lower than the solubility limit temperature, and detecting crystal defects revealed thereby, can surely and effectively reveal crystal defects even in silicon single crystal substrates with extremely low oxygen concentrations, and can detect them with high sensitivity, thereby completing the present invention.
図１は、本発明のシリコン単結晶基板の結晶欠陥の検出方法の工程の一例を示すフローチャートである。
まず、図１のＳ１のように、結晶欠陥を検出して評価するシリコン単結晶基板（半導体シリコン基板）を準備する。評価するシリコン単結晶基板は、チョクラルスキー法で製造されたものでも良いし、フローティングゾーン法で製造されたものでも良い。また、結晶方位は特に限定されない。直径サイズ、抵抗率、ドーパント種なども特に限定されない。
また、酸素濃度も限定されないが、後述するように特には０．４６ｐｐｍａより大という、極低酸素濃度のものとすることができる。従来法（特許文献２など）では適用できなかった低酸素濃度（例えば１．２ｐｐｍａ未満）の基板であっても、本発明では結晶欠陥の顕在化を確実に行うことが可能である。
FIG. 1 is a flow chart showing an example of the steps of a method for detecting crystal defects in a silicon single crystal substrate according to the present invention.
First, as shown in S1 of Fig. 1, a silicon single crystal substrate (semiconductor silicon substrate) for detecting and evaluating crystal defects is prepared. The silicon single crystal substrate to be evaluated may be one manufactured by the Czochralski method or one manufactured by the floating zone method. The crystal orientation is not particularly limited. The diameter size, resistivity, dopant species, etc. are not particularly limited.
In addition, the oxygen concentration is not limited, but can be an extremely low oxygen concentration of more than 0.46 ppma as described later. Even in the case of a substrate with a low oxygen concentration (for example, less than 1.2 ppma) that could not be applied by the conventional method (Patent Document 2, etc.), the present invention can reliably make crystal defects visible.
次に、Ｓ２のように、シリコン単結晶基板の酸素濃度を測定し、熱処理の温度を決定する。より具体的には以下の工程Ａ－Ｃを含む。
シリコン単結晶基板の酸素濃度を測定する（工程Ａ）。
シリコン単結晶基板の酸素濃度の測定方法は特に限定されず、例えば赤外吸収分光法により測定することができる。
Next, as in S2, the oxygen concentration of the silicon single crystal substrate is measured and the temperature of the heat treatment is determined. More specifically, the method includes the following steps A to C.
The oxygen concentration of the silicon single crystal substrate is measured (step A).
The method for measuring the oxygen concentration of the silicon single crystal substrate is not particularly limited, and the measurement can be performed by, for example, infrared absorption spectroscopy.
工程Ａで測定したシリコン単結晶基板の酸素濃度から酸素の固溶限界温度を求める（工程Ｂ）。
ここでシリコン単結晶中の酸素濃度、特には固溶度（固溶限）［Ｏ］ｓと固溶限界温度との関係について説明する。酸素の固溶度［Ｏ］ｓ（原子／ｃｍ３）と固溶限界温度Ｔ（Ｋ）については、様々な調査がなされており、例えば、ＵＣＳ半導体基盤技術研究会、シリコンの科学、リアライズ理工センター（株）、１９９６年には次のような関係式が開示されている。
［Ｏ］ｓ＝１．９１×１０２２ｅｘｐ（－１．００３／ｋＴ） （ここで、ｋ：８．６２×１０－５）…（式１）
また、志村史夫、半導体シリコン結晶工学、丸善（株）、１９９３年には次のような関係式が開示されている。
［Ｏ］ｓ＝９×１０２２ｅｘｐ（－１．５２／ｋＴ） （ここで、ｋ：８．６２×１０－５）…（式２）
The solubility limit temperature of oxygen is calculated from the oxygen concentration of the silicon single crystal substrate measured in step A (step B).
Here, the relationship between the oxygen concentration in a silicon single crystal, particularly the solid solubility (solid solubility limit) [O]s and the solid solubility limit temperature will be explained. Various investigations have been conducted on the solid solubility of oxygen [O]s (atoms/ cm3 ) and the solid solubility limit temperature T (K), and for example, the following relational formula was disclosed in UCS Semiconductor Fundamental Technology Research Group, Science of Silicon, Realize Science and Engineering Center Co., Ltd., 1996.
[O]s=1.91×10 22 exp(−1.003/kT) (where k: 8.62×10 −5 )...(Equation 1)
Furthermore, Shimura Fumio, Semiconductor Silicon Crystal Engineering, Maruzen Co., Ltd., 1993, discloses the following relational expression.
[O]s=9×10 22 exp(−1.52/kT) (where k: 8.62×10 −5 )...(Equation 2)
式１、式２のような酸素の固溶度と固溶限界温度との関係式を用い、測定した酸素濃度からその酸素濃度における固溶限界温度を算出することができる。なお、上記のように、参考文献によっては、開示されている酸素の固溶度の式が異なっている。各種条件により、その都度、使用する酸素の固溶度の式を決定することができる。
ここでは、式１を用いて固溶限界温度を求める場合を考える。
ところでこれらの文献の式１、式２においては、酸素濃度はｏｌｄ ＡＳＴＭ規格によるものであり、ＪＥＩＴＡ規格ではない。したがって、これらの式での［Ｏ］ｓ（原子／ｃｍ３）（ｏｌｄ ＡＳＴＭ規格）の値がＡの場合、（ｐｐｍａ）（ＪＥＩＴＡ規格）に換算すると、Ａ／（５×１０１６×１．６）となる。
Using the relationship between the oxygen solubility and the solubility limit temperature, such as Equation 1 and Equation 2, the solubility limit temperature at the measured oxygen concentration can be calculated. As mentioned above, the formula for the oxygen solubility disclosed in the reference documents varies. The formula for the oxygen solubility to be used can be determined each time depending on various conditions.
Here, the case of calculating the solubility limit temperature using Equation 1 will be considered.
In the formulas 1 and 2 in these documents, the oxygen concentration is based on the old ASTM standard, not the JEITA standard. Therefore, if the value of [O]s (atoms/ cm3 ) (old ASTM standard) in these formulas is A, when converted to (ppma) (JEITA standard), it becomes A/(5 x 1016 x 1.6).
次に、シリコン単結晶基板に、後の工程で施す熱処理の熱処理温度を８００℃以上、かつ、工程Ｂで求めた酸素の固溶限界温度未満の温度の範囲に決定する（工程Ｃ）。
後の工程でシリコン単結晶基板に熱処理を施して結晶欠陥を顕在化するが、８００℃未満であると、エッチングが進行せず結晶欠陥を顕在化することができないし、できたとしても基板のエッチング速度が非常に遅く、極めて長時間の熱処理が必要になる。
また、熱処理温度が固溶限界温度以上であると、熱処理により結晶欠陥が容体化してしまい、結晶欠陥を顕在化することができなくなる。そのため、工程Ｂで求めた固溶限界温度の値未満に設定することにより、このような結晶欠陥の容体化を防ぐことができ、結晶欠陥を確実に顕在化することができる。
このような温度範囲内から熱処理の工程での熱処理温度を適宜決定することができる。式１から求めた固溶限界温度は、熱処理温度の上限値を決定する目安であって、実際の熱処理の工程の熱処理温度条件としては、より好ましくは求めた固溶限界温度よりも十分低くすることができる。
Next, the heat treatment temperature for the heat treatment to be performed on the silicon single crystal substrate in a subsequent step is determined to be in the range of 800° C. or higher and lower than the solubility limit temperature of oxygen determined in step B (step C).
In a later process, the silicon single crystal substrate is subjected to a heat treatment to expose the crystal defects. However, if the temperature is less than 800° C., the etching will not proceed and the crystal defects will not be able to be exposed. Even if it is possible, the etching rate of the substrate will be very slow, requiring an extremely long heat treatment time.
Furthermore, if the heat treatment temperature is equal to or higher than the solubility limit temperature, the crystal defects will be converted into a solution by the heat treatment, and the crystal defects will not be made visible. Therefore, by setting the heat treatment temperature to a temperature lower than the solubility limit temperature obtained in step B, it is possible to prevent such crystal defects from being converted into a solution, and it is possible to reliably make the crystal defects visible.
The heat treatment temperature in the heat treatment step can be appropriately determined within such a temperature range. The solubility limit temperature calculated from Equation 1 is a guide for determining the upper limit of the heat treatment temperature, and the heat treatment temperature condition in the actual heat treatment step can more preferably be sufficiently lower than the calculated solubility limit temperature.
なお、上記のように結晶欠陥を効率良く顕在化するためには熱処理温度を８００℃以上にする必要があり、式１からすると、固溶限界温度が８００℃の酸素濃度は０．４６ｐｐｍａとなる。したがって、特に、酸素濃度が０．４６ｐｐｍａよりも大きいものの０．４６ｐｐｍａに近い、極めて低い酸素濃度のシリコン単結晶基板であっても（この場合、固溶限界温度は８００℃より僅かに高い程度となる）、熱処理温度をその固溶限界温度未満の８００℃とすることにより、結晶欠陥の容体化を防ぎ、結晶欠陥を顕在化することができる。 As mentioned above, in order to efficiently expose crystal defects, the heat treatment temperature must be 800°C or higher, and according to formula 1, the oxygen concentration at a solubility limit temperature of 800°C is 0.46 ppma. Therefore, even in a silicon single crystal substrate with an extremely low oxygen concentration, greater than but close to 0.46 ppma (in this case, the solubility limit temperature is only slightly higher than 800°C), the heat treatment temperature can be set to 800°C, which is lower than the solubility limit temperature, to prevent crystal defects from becoming solidified and expose the crystal defects.
Ｓ２の工程Ａ－Ｃについて説明したが、ここで結晶欠陥の検出対象が複数のシリコン単結晶基板である場合の好ましい例について説明する。後の熱処理の工程で、複数のシリコン単結晶基板を同時に熱処理して結晶欠陥を顕在化する場合、工程Ａではその複数のシリコン単結晶基板の全てについて酸素濃度を測定する。あるいは、インゴットからの切り出し箇所が隣接しているなど酸素濃度が同じとみなすことができるのであれば、１つ以上の基板を代表として選出し、その代表のものだけ測定してもよい。
そして工程Ｂではシリコン単結晶基板の最も低い酸素濃度の測定値から固溶限界温度を式１を用いて求める。
そして工程Ｃにおいて、前述したのと同様にして８００℃以上、かつ求めた酸素の固溶限界温度未満の温度の範囲内で、後の工程の熱処理の熱処理温度を決定する。このような熱処理条件とすれば、複数のシリコン単結晶基板を同一熱処理温度条件で同時に熱処理することができるので簡単であるし、効率的である。
Steps A to C of S2 have been described above, but here we will describe a preferred example in which the detection target for crystal defects is a plurality of silicon single crystal substrates. In the case where a plurality of silicon single crystal substrates are simultaneously heat-treated in a subsequent heat treatment step to make crystal defects apparent, the oxygen concentration is measured for all of the plurality of silicon single crystal substrates in step A. Alternatively, if the oxygen concentrations can be considered to be the same, for example, because the portions cut from an ingot are adjacent to each other, one or more substrates may be selected as representatives and only the representative substrates may be measured.
In step B, the solubility limit temperature is calculated using equation 1 from the measured value of the lowest oxygen concentration in the silicon single crystal substrate.
Then, in step C, the heat treatment temperature for the subsequent heat treatment is determined within the range of 800° C. or higher and lower than the determined solubility limit temperature of oxygen, in the same manner as described above. By using such heat treatment conditions, a plurality of silicon single crystal substrates can be simultaneously heat-treated under the same heat treatment temperature conditions, which is simple and efficient.
次に、Ｓ３のように、シリコン単結晶基板を鏡面研磨する。
シリコン単結晶基板を鏡面研磨することができれば良く、両面研磨機や片面研磨機等を用いて行うことができる。
Next, as in S3, the silicon single crystal substrate is mirror-polished.
It is sufficient if the silicon single crystal substrate can be mirror-polished, and this can be done using a double-sided polisher, single-sided polisher, or the like.
次に、Ｓ４のように、シリコン単結晶基板を洗浄する。
この洗浄としては、ＳＣ－１洗浄、ＳＣ－２洗浄による２段階洗浄を行うことができるし、自然酸化膜除去のためにフッ酸を用いても良い。さらに、ＳＣ－１洗浄、ＳＣ－２洗浄による２段階洗浄とフッ酸洗浄を組み合わせてもよい。必要に応じて純水等でリンスしてもよい。
Next, as in S4, the silicon single crystal substrate is cleaned.
This cleaning can be performed in two stages, SC-1 cleaning and SC-2 cleaning, or hydrofluoric acid cleaning can be used to remove natural oxide films. Furthermore, the two-stage cleaning, SC-1 cleaning and SC-2 cleaning, can be combined with hydrofluoric acid cleaning. If necessary, rinsing with pure water or the like can be performed.
このようなＳ３の鏡面研磨、Ｓ４の洗浄を行ってから、次のＳ５の熱処理を行なうことで、熱処理前に予めシリコン単結晶基板の表面付近の金属不純物やパーティクルなどの異物を除去することができる。そのため、熱処理で結晶欠陥のみを顕在化することができるので好ましい。 By carrying out the mirror polishing in S3 and cleaning in S4, followed by the heat treatment in S5, it is possible to remove foreign matter such as metal impurities and particles near the surface of the silicon single crystal substrate before the heat treatment. This is preferable because it allows only crystal defects to become apparent during the heat treatment.
次に、Ｓ５のように、シリコン単結晶基板を熱処理する。より具体的には、水素と塩化水素とを含む雰囲気下で、工程Ｃで決定した熱処理温度で熱処理する（工程Ｄ）。使用する熱処理装置は特に限定されず、従来からの抵抗加熱装置などを用いることができる。
シリコン単結晶基板表面上の無欠陥の部分と欠陥の部分では、水素や塩化水素によるエッチング速度が異なるため、水素と塩化水素を含む雰囲気下で熱処理することで、欠陥の部分周辺に方位性のあるエッチピットを形成することができ、結晶欠陥を顕在化することができる。
また、この熱処理の時間は、結晶欠陥が顕在化されるのに十分な時間に決定することができる。例えば３０秒であっても良いし、６００秒であっても良いが、スループットを考慮すると、６００秒以内が好ましい。より好ましくは６０～１８０秒とすることができる。
Next, as in S5, the silicon single crystal substrate is heat-treated. More specifically, the substrate is heat-treated in an atmosphere containing hydrogen and hydrogen chloride at the heat treatment temperature determined in step C (step D). The heat treatment device used is not particularly limited, and a conventional resistance heating device or the like can be used.
Since the etching rates by hydrogen and hydrogen chloride differ between defect-free and defective areas on the surface of a silicon single crystal substrate, heat treatment in an atmosphere containing hydrogen and hydrogen chloride can form oriented etch pits around the defective areas, making the crystal defects visible.
The time for this heat treatment can be determined to be a time sufficient for crystal defects to become apparent. For example, it may be 30 seconds or 600 seconds, but considering the throughput, it is preferably within 600 seconds. More preferably, it can be 60 to 180 seconds.
なお、シリコン単結晶基板が複数の場合は、前述したように、工程Ｃで最も低い酸素濃度から求めた固溶限界温度を上限とした範囲から決定した熱処理温度で、その複数のシリコン単結晶基板を同時に熱処理する。 When there are multiple silicon single crystal substrates, as described above, the multiple silicon single crystal substrates are simultaneously heat-treated at a heat treatment temperature determined from a range with the solubility limit temperature determined from the lowest oxygen concentration in step C as the upper limit.
次に、Ｓ６のように、Ｓ５（工程Ｄ）で熱処理を施したシリコン単結晶基板の表面に顕在化した結晶欠陥の検出を行う（工程Ｅ）。また、Ｓ７のように、検出した結晶欠陥の評価を行う。
検出手段は特に限定されないが、例えば、表面欠陥検出装置及び走査型電子顕微鏡のうち少なくとも１つを用いて行うことができる。表面欠陥検出装置（例えば、ＭＡＧＩＣＳ、ＳＰ１、ＳＰ２等）を用いることで欠陥を短時間で正確に検出することができる。また、走査型電子顕微鏡を用いて検出することで結晶欠陥の種類、形態、構成元素等を評価することができる。さらには、これらの両方を用いても良く、表面欠陥検出装置で検出し、この検出結果に基づいて走査型電子顕微鏡で結晶欠陥の種類等について評価しても良い。
Next, as in S6, crystal defects that have become apparent on the surface of the silicon single crystal substrate that has been heat-treated in S5 (step D) are detected (step E). Also, as in S7, the detected crystal defects are evaluated.
The detection means is not particularly limited, and may be, for example, at least one of a surface defect detection device and a scanning electron microscope. By using a surface defect detection device (e.g., MAGICS, SP1, SP2, etc.), defects can be accurately detected in a short time. Furthermore, by detecting using a scanning electron microscope, the type, form, constituent elements, etc. of the crystal defect can be evaluated. Furthermore, both of these may be used, and detection may be performed using the surface defect detection device, and the type, etc. of the crystal defect may be evaluated using a scanning electron microscope based on the detection results.
以上のような本発明の検出方法であれば、たとえ従来法では結晶欠陥の顕在化が難しい程の低酸素濃度のシリコン単結晶基板であったとしても、短時間で効率良く、また、結晶欠陥を容体化させることなく確実に顕在化することができ、高感度で検出することができる。 The detection method of the present invention as described above can efficiently detect crystal defects in a short time, without causing them to turn to solution, and with high sensitivity, even in cases where the silicon single crystal substrate has such a low oxygen concentration that it is difficult to detect crystal defects using conventional methods.
以下、実施例および比較例を示して本発明をより具体的に説明するが、本発明はこれらの実施例に限定されるものではない。
（実施例１）
まず、評価するサンプルとして、チョクラルスキー法を用いて空孔形成が優勢となるような条件で製造された直径３００ｍｍのシリコン単結晶基板を２枚用意した。
次に、シリコン単結晶基板の酸素濃度を赤外吸収分光法で測定したところ、共に１２ｐｐｍａであった。
上記式１より固溶限界温度は約１２６０℃であるため、熱処理温度を１０００℃に決定した。
次に、これらのシリコン単結晶基板を鏡面研磨し、シリコン単結晶基板を洗浄した（ＳＣ－１洗浄、ＳＣ－２洗浄、フッ酸洗浄）。
The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.
Example 1
First, two silicon single crystal substrates with a diameter of 300 mm, which were manufactured using the Czochralski method under conditions in which void formation was predominant, were prepared as samples to be evaluated.
Next, the oxygen concentration of the silicon single crystal substrate was measured by infrared absorption spectroscopy, and was found to be 12 ppma in both cases.
According to the above formula 1, the solid solution limit temperature is about 1260°C, so the heat treatment temperature was determined to be 1000°C.
Next, these silicon single crystal substrates were mirror-polished and cleaned (SC-1 cleaning, SC-2 cleaning, and hydrofluoric acid cleaning).
その後、２枚のうちの１枚について決定した熱処理温度で水素と塩化水素を含む雰囲気下で熱処理した。このとき、塩化水素の体積％濃度は２％とし、熱処理時間は６０秒とした。
もう１枚については、本発明の効果を確認するための基準とするため、熱処理を行わなかった。
その後、熱処理後のシリコン単結晶基板＜熱処理有り＞と、熱処理を行なわなかった基準のシリコン単結晶基板＜熱処理無し＞とについて、表面欠陥検出装置及び走査型電子顕微鏡で結晶欠陥を検出した。
Then, one of the two pieces was heat-treated at the determined heat treatment temperature in an atmosphere containing hydrogen and hydrogen chloride, where the volume percent concentration of hydrogen chloride was 2%, and the heat treatment time was 60 seconds.
The other sheet was not subjected to heat treatment in order to serve as a reference for confirming the effect of the present invention.
Thereafter, crystal defects were detected using a surface defect detection device and a scanning electron microscope for the silicon single crystal substrate after the heat treatment (with heat treatment) and a reference silicon single crystal substrate that had not been subjected to heat treatment (without heat treatment).
検出された欠陥数を本発明における熱処理の有無で比較することにより顕在化効果を確認した。このとき、＜熱処理無し＞の欠陥密度を１として比較した。
その結果、＜熱処理有り＞の欠陥数は、＜熱処理無し＞と比較して４．１倍となり、本発明の検出方法における熱処理の欠陥顕在化効果が確認された。
なお、実施例１と後述する実施例２、３、比較例１、２の各種条件、顕在化効果（欠陥増加率）を表１にまとめる。
The number of detected defects was compared between those with and without the heat treatment of the present invention, and the effect of making defects more apparent was confirmed. At this time, the defect density without heat treatment was set to 1 for comparison.
As a result, the number of defects in the case of "with heat treatment" was 4.1 times that in the case of "without heat treatment," confirming the effect of heat treatment in making defects apparent in the detection method of the present invention.
Table 1 shows the various conditions and the manifestation effects (defect increase rate) of Example 1, Examples 2 and 3, and Comparative Examples 1 and 2 described below.
（実施例２）
まず、評価するサンプルとして、チョクラルスキー法を用いて空孔形成が優勢となるような条件で製造された直径３００ｍｍのシリコン単結晶基板を２枚用意した。
次に、シリコン単結晶基板の酸素濃度を赤外吸収分光法で測定したところ、共に４．１ｐｐｍａであった。
上記式１より固溶限界温度は約１０７０℃であるため、熱処理温度を１０００℃に決定した。
次に、これらのシリコン単結晶基板を鏡面研磨し、シリコン単結晶基板を洗浄した（ＳＣ－１洗浄、ＳＣ－２洗浄、フッ酸洗浄）。
Example 2
First, two silicon single crystal substrates with a diameter of 300 mm, which were manufactured using the Czochralski method under conditions in which void formation was predominant, were prepared as samples to be evaluated.
Next, the oxygen concentration of the silicon single crystal substrate was measured by infrared absorption spectroscopy, and was found to be 4.1 ppma in both cases.
According to the above formula 1, the solid solution limit temperature is about 1070°C, so the heat treatment temperature was determined to be 1000°C.
Next, these silicon single crystal substrates were mirror-polished and cleaned (SC-1 cleaning, SC-2 cleaning, and hydrofluoric acid cleaning).
その後、２枚のうちの１枚について決定した熱処理温度で水素と塩化水素を含む雰囲気下で熱処理した。このとき、塩化水素の体積％濃度は２％とし、熱処理時間は６０秒とした。
もう１枚については、本発明の効果を確認するための基準とするため、熱処理を行わなかった。
その後、熱処理後のシリコン単結晶基板＜熱処理有り＞と、熱処理を行なわなかった基準のシリコン単結晶基板＜熱処理無し＞とについて、表面欠陥検出装置及び走査型電子顕微鏡で結晶欠陥を検出した。
Then, one of the two pieces was heat-treated at the determined heat treatment temperature in an atmosphere containing hydrogen and hydrogen chloride, where the volume percent concentration of hydrogen chloride was 2%, and the heat treatment time was 60 seconds.
The other sheet was not subjected to heat treatment in order to serve as a reference for confirming the effect of the present invention.
Thereafter, crystal defects were detected using a surface defect detection device and a scanning electron microscope for the silicon single crystal substrate after the heat treatment (with heat treatment) and a reference silicon single crystal substrate that had not been subjected to heat treatment (without heat treatment).
検出された欠陥数を本発明における熱処理の有無で比較することにより顕在化効果を確認した。このとき、＜熱処理無し＞の欠陥密度を１として比較した。
その結果、＜熱処理有り＞の欠陥数は、＜熱処理無し＞と比較して２．２倍となり、本発明の検出方法における熱処理の欠陥顕在化効果が確認された。
The number of detected defects was compared between those with and without the heat treatment of the present invention, and the effect of making defects more apparent was confirmed. At this time, the defect density without heat treatment was set to 1 for comparison.
As a result, the number of defects in the case of "with heat treatment" was 2.2 times that in the case of "without heat treatment," confirming the effect of heat treatment in making defects apparent in the detection method of the present invention.
（実施例３）
まず、評価するサンプルとして、チョクラルスキー法を用いて空孔形成が優勢となるような条件で製造された直径３００ｍｍのシリコン単結晶基板を２枚用意した。
次に、シリコン単結晶基板の酸素濃度を赤外吸収分光法で測定したところ、共に２．０ｐｐｍａであった。
上記式１より固溶限界温度は約９７０℃であるため、熱処理温度を８５０℃に決定した。
次に、これらのシリコン単結晶基板を鏡面研磨し、シリコン単結晶基板を洗浄した（ＳＣ－１洗浄、ＳＣ－２洗浄、フッ酸洗浄）。
Example 3
First, two silicon single crystal substrates with a diameter of 300 mm, which were manufactured using the Czochralski method under conditions in which void formation was predominant, were prepared as samples to be evaluated.
Next, the oxygen concentration of the silicon single crystal substrate was measured by infrared absorption spectroscopy, and was found to be 2.0 ppma in both cases.
Since the solubility limit temperature is about 970°C according to the above formula 1, the heat treatment temperature was determined to be 850°C.
Next, these silicon single crystal substrates were mirror-polished and cleaned (SC-1 cleaning, SC-2 cleaning, and hydrofluoric acid cleaning).
その後、２枚のうちの１枚について決定した熱処理温度で水素と塩化水素を含む雰囲気下で熱処理した。このとき、塩化水素の体積％濃度は２％とし、熱処理時間は６０秒とした。
もう１枚については、本発明の効果を確認するための基準とするため、熱処理を行わなかった。
その後、熱処理後のシリコン単結晶基板＜熱処理有り＞と、熱処理を行なわなかった基準のシリコン単結晶基板＜熱処理無し＞とについて、表面欠陥検出装置及び走査型電子顕微鏡で結晶欠陥を検出した。
Then, one of the two pieces was heat-treated at the determined heat treatment temperature in an atmosphere containing hydrogen and hydrogen chloride, where the volume percent concentration of hydrogen chloride was 2%, and the heat treatment time was 60 seconds.
The other sheet was not subjected to heat treatment in order to serve as a reference for confirming the effect of the present invention.
Thereafter, crystal defects were detected using a surface defect detection device and a scanning electron microscope for the silicon single crystal substrate after the heat treatment (with heat treatment) and a reference silicon single crystal substrate that had not been subjected to heat treatment (without heat treatment).
検出された欠陥数を本発明における熱処理の有無で比較することにより顕在化効果を確認した。このとき、＜熱処理無し＞の欠陥密度を１として比較した。
その結果、＜熱処理有り＞の欠陥数は、＜熱処理無し＞と比較して５．７倍となり、本発明の検出方法における熱処理の欠陥顕在化効果が確認された。
The number of detected defects was compared between those with and without the heat treatment of the present invention, and the effect of making defects more apparent was confirmed. At this time, the defect density without heat treatment was set to 1 for comparison.
As a result, the number of defects in the case of "with heat treatment" was 5.7 times that in the case of "without heat treatment," confirming the effect of heat treatment in making defects apparent in the detection method of the present invention.
（比較例１）
まず、評価するサンプルとして、チョクラルスキー法を用いて空孔形成が優勢となるような条件で製造された直径３００ｍｍのシリコン単結晶基板を２枚用意した。
次に、シリコン単結晶基板の酸素濃度を赤外吸収分光法で測定したところ、共に２．０ｐｐｍａであった。
上記式１より固溶限界温度は約９７０℃であり、熱処理温度を７００℃に決定した。
次に、シリコン単結晶基板を鏡面研磨し、シリコン単結晶基板を洗浄した（ＳＣ－１洗浄、ＳＣ－２洗浄、フッ酸洗浄）。
(Comparative Example 1)
First, two silicon single crystal substrates with a diameter of 300 mm, which were manufactured using the Czochralski method under conditions in which void formation was predominant, were prepared as samples to be evaluated.
Next, the oxygen concentration of the silicon single crystal substrate was measured by infrared absorption spectroscopy, and was found to be 2.0 ppma in both cases.
According to the above formula 1, the solid solution limit temperature is about 970°C, and the heat treatment temperature was determined to be 700°C.
Next, the silicon single crystal substrate was mirror-polished and cleaned (SC-1 cleaning, SC-2 cleaning, and hydrofluoric acid cleaning).
その後、２枚のうちの１枚について決定した熱処理温度で水素と塩化水素を含む雰囲気下で熱処理した。このとき、塩化水素の体積％濃度は２％とし、熱処理時間は６０秒とした。
もう１枚については、熱処理の効果を確認するための基準とするため、熱処理を行わなかった。
その後、熱処理後のシリコン単結晶基板＜熱処理有り＞と、熱処理を行なわなかった基準のシリコン単結晶基板＜熱処理無し＞とについて、表面欠陥検出装置及び走査型電子顕微鏡で結晶欠陥を検出した。
Then, one of the two pieces was heat-treated at the determined heat treatment temperature in an atmosphere containing hydrogen and hydrogen chloride, where the volume percent concentration of hydrogen chloride was 2%, and the heat treatment time was 60 seconds.
The other sheet was not subjected to heat treatment in order to serve as a reference for confirming the effect of heat treatment.
Thereafter, crystal defects were detected using a surface defect detection device and a scanning electron microscope for the silicon single crystal substrate after the heat treatment (with heat treatment) and a reference silicon single crystal substrate that had not been subjected to heat treatment (without heat treatment).
検出された欠陥数を上記熱処理の有無で比較することにより顕在化効果を確認した。このとき、＜熱処理無し＞の欠陥密度を１として比較した。
その結果、＜熱処理有り＞の欠陥数は、＜熱処理無し＞と比較して１．４倍となり、上記熱処理の欠陥顕在化効果はほとんど確認されなかった。８００℃未満であったため、エッチングが進行せず、結晶欠陥を顕在化することができなかったためと考えられる。
The number of defects detected was compared between those with and without the heat treatment, and the effect of making defects more apparent was confirmed. At this time, the defect density without heat treatment was set to 1.
As a result, the number of defects in the case of "with heat treatment" was 1.4 times that in the case of "without heat treatment," and the effect of the heat treatment on revealing defects was hardly confirmed. This is thought to be because the etching did not progress because the temperature was less than 800° C., and the crystal defects could not be revealed.
（比較例２）
まず、評価するサンプルとして、チョクラルスキー法を用いて空孔形成が優勢となるような条件で製造された直径３００ｍｍのシリコン単結晶基板を２枚用意した。
次に、シリコン単結晶基板の酸素濃度を赤外吸収分光法で測定したところ、共に２．０ｐｐｍａであった。
そして、熱処理温度を１０００℃に決定した。但し、上記式１より求めた固溶限界温度は約９７０℃である。
次に、シリコン単結晶基板を鏡面研磨し、シリコン単結晶基板を洗浄した（ＳＣ－１洗浄、ＳＣ－２洗浄、フッ酸洗浄）。
(Comparative Example 2)
First, two silicon single crystal substrates with a diameter of 300 mm, which were manufactured using the Czochralski method under conditions in which void formation was predominant, were prepared as samples to be evaluated.
Next, the oxygen concentration of the silicon single crystal substrate was measured by infrared absorption spectroscopy, and was found to be 2.0 ppma in both cases.
The heat treatment temperature was then determined to be 1000° C. However, the solubility limit temperature calculated from the above formula 1 was approximately 970° C.
Next, the silicon single crystal substrate was mirror-polished and cleaned (SC-1 cleaning, SC-2 cleaning, and hydrofluoric acid cleaning).
その後、２枚のうちの１枚について決定した熱処理温度で水素と塩化水素を含む雰囲気下で熱処理した。このとき、塩化水素の体積％濃度は２％とし、熱処理時間は６０秒とした。
もう１枚については、熱処理の効果を確認するための基準とするため、熱処理を行わなかった。
その後、熱処理後のシリコン単結晶基板＜熱処理有り＞と、熱処理を行なわなかった基準のシリコン単結晶基板＜熱処理無し＞とについて、表面欠陥検出装置及び走査型電子顕微鏡で欠陥を検出した。
Then, one of the two pieces was heat-treated at the determined heat treatment temperature in an atmosphere containing hydrogen and hydrogen chloride, where the volume percent concentration of hydrogen chloride was 2%, and the heat treatment time was 60 seconds.
The other sheet was not subjected to heat treatment in order to serve as a reference for confirming the effect of heat treatment.
Thereafter, defects were detected using a surface defect detection device and a scanning electron microscope for the silicon single crystal substrate after the heat treatment (with heat treatment) and a reference silicon single crystal substrate that had not been subjected to heat treatment (without heat treatment).
検出された欠陥数を上記熱処理の有無で比較することにより顕在化効果を確認した。このとき、＜熱処理無し＞の欠陥密度を１として比較した。
その結果、＜熱処理有り＞の欠陥数は、＜熱処理無し＞と比較して１．３倍となり、欠陥顕在化効果はほとんど確認されなかった。このように酸素濃度が同じ実施例３に比べ、欠陥検出をするにあたって十分に顕在化することができなかった。また酸素濃度は異なるが、欠陥顕在化効果（欠陥増加率）について実施例１、２と比較しても小さい。これは熱処理温度（１０００℃）が固溶限界温度（約９７０℃）以上の温度であったため、結晶欠陥が容体化してしまったことが原因と考えられる。
The number of defects detected was compared between those with and without the heat treatment, and the effect of making defects more apparent was confirmed. At this time, the defect density without heat treatment was set to 1.
As a result, the number of defects in the case of <with heat treatment> was 1.3 times that of the case of <without heat treatment>, and the defect manifestation effect was hardly confirmed. Thus, compared to Example 3, which had the same oxygen concentration, defects could not be sufficiently manifested for detection. Also, although the oxygen concentration was different, the defect manifestation effect (defect increase rate) was smaller than in Examples 1 and 2. This is thought to be due to the fact that the heat treatment temperature (1000°C) was above the solid solution limit temperature (approximately 970°C), causing the crystal defects to become liquid.
本明細書は、以下の態様を包含する。
［１］： シリコン単結晶基板に熱処理を施し、該シリコン単結晶基板に存在する結晶欠陥を検出する方法であって、
前記シリコン単結晶基板の酸素濃度を測定する工程Ａと、
前記測定したシリコン単結晶基板の酸素濃度から酸素の固溶限界温度を求める工程Ｂと、
前記シリコン単結晶基板に施す前記熱処理の熱処理温度を８００℃以上、かつ前記求めた酸素の固溶限界温度未満の温度の範囲に決定する工程Ｃと、
前記シリコン単結晶基板を、水素と塩化水素とを含む雰囲気下で、前記決定した熱処理温度で前記熱処理を施す工程Ｄと、
前記熱処理を施したシリコン単結晶基板の表面に顕在化した結晶欠陥の検出を行う工程Ｅと、
を含むシリコン単結晶基板の結晶欠陥の検出方法。
［２］： 前記シリコン単結晶基板の酸素濃度を０．４６ｐｐｍａより大とする上記［１］のシリコン単結晶基板の結晶欠陥の検出方法。
［３］： 前記工程Ｄにおいて複数の前記シリコン単結晶基板に同時に前記熱処理を施す場合、
前記工程Ｂで求める前記酸素の固溶限界温度を、前記複数のシリコン単結晶基板のうち最も低い酸素濃度から求める上記［１］または上記［２］のシリコン単結晶基板の結晶欠陥の検出方法。
［４］： 前記工程Ｄにおいて前記熱処理を施すとき、前記シリコン単結晶基板の表面を鏡面研磨した後、洗浄を行ってから施すことを特徴とする上記［１］から上記［３］のいずれかのシリコン単結晶基板の結晶欠陥の検出方法。
［５］： 前記工程Ｅにおける前記顕在化した結晶欠陥の検出を、表面欠陥検出装置及び走査型電子顕微鏡のうち少なくとも１つを用いて行う上記［１］から上記［４］のいずれかのシリコン単結晶基板の結晶欠陥の検出方法。
The present specification includes the following aspects.
[1]: A method for detecting crystal defects present in a silicon single crystal substrate by subjecting the silicon single crystal substrate to a heat treatment, comprising the steps of:
A step A of measuring an oxygen concentration of the silicon single crystal substrate;
A step B of determining a solid solubility limit temperature of oxygen from the oxygen concentration of the silicon single crystal substrate measured;
A step C of determining a heat treatment temperature of the heat treatment to be performed on the silicon single crystal substrate to be in a range of 800° C. or higher and lower than the determined solid solubility limit temperature of oxygen;
A step D of subjecting the silicon single crystal substrate to the heat treatment at the determined heat treatment temperature in an atmosphere containing hydrogen and hydrogen chloride;
A step E of detecting crystal defects that have become apparent on the surface of the heat-treated silicon single crystal substrate;
A method for detecting crystal defects in a silicon single crystal substrate, comprising:
[2]: The method for detecting crystal defects in a silicon single crystal substrate according to the above [1], wherein the oxygen concentration in the silicon single crystal substrate is set to be greater than 0.46 ppma.
[3]: When the heat treatment is performed simultaneously on a plurality of the silicon single crystal substrates in the step D,
The method for detecting crystal defects in a silicon single crystal substrate according to the above [1] or [2], wherein the solubility limit temperature of oxygen determined in the step B is determined from the lowest oxygen concentration among the plurality of silicon single crystal substrates.
[4]: The method for detecting crystal defects in a silicon single crystal substrate according to any one of [1] to [3] above, characterized in that when the heat treatment is performed in step D, the surface of the silicon single crystal substrate is mirror-polished and then cleaned before the heat treatment.
[5]: A method for detecting crystal defects in a silicon single crystal substrate according to any one of [1] to [4] above, wherein the detection of the crystal defects that have become apparent in step E is performed using at least one of a surface defect detection device and a scanning electron microscope.
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-described embodiment. The above-described embodiment is merely an example, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included within the technical scope of the present invention.
Claims (7)
前記シリコン単結晶基板の酸素濃度を測定する工程Ａと、
前記測定したシリコン単結晶基板の酸素濃度から酸素の固溶限界温度を求める工程Ｂと、
前記シリコン単結晶基板に施す前記熱処理の熱処理温度を８００℃以上、かつ前記求めた酸素の固溶限界温度未満の温度の範囲に決定する工程Ｃと、
前記シリコン単結晶基板を、水素と塩化水素とを含む雰囲気下で、前記決定した熱処理温度で前記熱処理を施す工程Ｄと、
前記熱処理を施したシリコン単結晶基板の表面に顕在化した結晶欠陥の検出を行う工程Ｅと、
を含むことを特徴とするシリコン単結晶基板の結晶欠陥の検出方法。 A method for detecting crystal defects present in a silicon single crystal substrate by subjecting the silicon single crystal substrate to a heat treatment, comprising the steps of:
A step A of measuring an oxygen concentration of the silicon single crystal substrate;
A step B of determining a solid solubility limit temperature of oxygen from the oxygen concentration of the silicon single crystal substrate measured;
A step C of determining a heat treatment temperature of the heat treatment to be performed on the silicon single crystal substrate to be in a range of 800° C. or higher and lower than the determined solid solubility limit temperature of oxygen;
A step D of subjecting the silicon single crystal substrate to the heat treatment at the determined heat treatment temperature in an atmosphere containing hydrogen and hydrogen chloride;
A step E of detecting crystal defects that have become apparent on the surface of the heat-treated silicon single crystal substrate;
1. A method for detecting crystal defects in a silicon single crystal substrate, comprising:
前記工程Ｂで求める前記酸素の固溶限界温度を、前記複数のシリコン単結晶基板のうち最も低い酸素濃度から求めることを特徴とする請求項１に記載のシリコン単結晶基板の結晶欠陥の検出方法。 When the heat treatment is performed simultaneously on a plurality of the silicon single crystal substrates in the step D,
2. The method for detecting crystal defects in a silicon single crystal substrate according to claim 1, wherein the solubility limit temperature of oxygen determined in step B is determined from the lowest oxygen concentration among the plurality of silicon single crystal substrates.
前記工程Ｂで求める前記酸素の固溶限界温度を、前記複数のシリコン単結晶基板のうち最も低い酸素濃度から求めることを特徴とする請求項２に記載のシリコン単結晶基板の結晶欠陥の検出方法。 When the heat treatment is performed simultaneously on a plurality of the silicon single crystal substrates in the step D,
3. The method for detecting crystal defects in a silicon single crystal substrate according to claim 2, wherein the solubility limit temperature of oxygen determined in step B is determined from the lowest oxygen concentration among the plurality of silicon single crystal substrates.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2022079085A JP7666396B2 (en) | 2022-05-12 | 2022-05-12 | Method for detecting crystal defects in silicon single crystal substrate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2022079085A JP7666396B2 (en) | 2022-05-12 | 2022-05-12 | Method for detecting crystal defects in silicon single crystal substrate |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2023167707A JP2023167707A (en) | 2023-11-24 |
| JP7666396B2 true JP7666396B2 (en) | 2025-04-22 |
Family
ID=88838301
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2022079085A Active JP7666396B2 (en) | 2022-05-12 | 2022-05-12 | Method for detecting crystal defects in silicon single crystal substrate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP7666396B2 (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002289820A (en) | 2001-03-28 | 2002-10-04 | Nippon Steel Corp | SIMOX substrate manufacturing method and SIMOX substrate |
| WO2005076333A1 (en) | 2004-02-03 | 2005-08-18 | Shin-Etsu Handotai Co., Ltd. | Method for manufacturing semiconductor wafer and system for determining cut position of semiconductor ingot |
| JP2013021276A (en) | 2011-07-14 | 2013-01-31 | Shin Etsu Handotai Co Ltd | Detection method of crystal defect |
| JP2014201458A (en) | 2013-04-02 | 2014-10-27 | 信越半導体株式会社 | Method of producing semiconductor wafer and system for determining cutting position of semiconductor ingot |
| JP2015501533A (en) | 2011-10-14 | 2015-01-15 | エムイーエムシー・エレクトロニック・マテリアルズ・インコーポレイテッドＭｅｍｃ Ｅｌｅｃｔｒｏｎｉｃ Ｍａｔｅｒｉａｌｓ，Ｉｎｃｏｒｐｏｒａｔｅｄ | Method for indicating the location of crystal related defects |
-
2022
- 2022-05-12 JP JP2022079085A patent/JP7666396B2/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002289820A (en) | 2001-03-28 | 2002-10-04 | Nippon Steel Corp | SIMOX substrate manufacturing method and SIMOX substrate |
| WO2005076333A1 (en) | 2004-02-03 | 2005-08-18 | Shin-Etsu Handotai Co., Ltd. | Method for manufacturing semiconductor wafer and system for determining cut position of semiconductor ingot |
| JP2013021276A (en) | 2011-07-14 | 2013-01-31 | Shin Etsu Handotai Co Ltd | Detection method of crystal defect |
| JP2015501533A (en) | 2011-10-14 | 2015-01-15 | エムイーエムシー・エレクトロニック・マテリアルズ・インコーポレイテッドＭｅｍｃ Ｅｌｅｃｔｒｏｎｉｃ Ｍａｔｅｒｉａｌｓ，Ｉｎｃｏｒｐｏｒａｔｅｄ | Method for indicating the location of crystal related defects |
| JP2014201458A (en) | 2013-04-02 | 2014-10-27 | 信越半導体株式会社 | Method of producing semiconductor wafer and system for determining cutting position of semiconductor ingot |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2023167707A (en) | 2023-11-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| TWI393168B (en) | Method for reducing metal contamination in germanium wafers | |
| US7901132B2 (en) | Method of identifying crystal defect region in monocrystalline silicon using metal contamination and heat treatment | |
| CN111624460B (en) | Method for detecting defect distribution area of monocrystalline silicon | |
| JP6933187B2 (en) | Method for removing metal impurities from semiconductor silicon wafers | |
| JPWO2001055485A1 (en) | Method for determining manufacturing conditions for silicon wafers and silicon single crystals, and method for manufacturing silicon wafers | |
| KR950004593B1 (en) | A semiconductor substrate, the manufacturing method of a semiconductor substrate and a semiconductor device, and the inspection and evaluation method of a semiconductor substrate | |
| JP6651134B2 (en) | Method for detecting crystal defects in semiconductor single crystal substrate | |
| JP2008222505A (en) | Method for evaluating silicon single crystal wafer and method for producing silicon single crystal | |
| JP6025070B2 (en) | Quality evaluation method of silicon single crystal | |
| JP7666396B2 (en) | Method for detecting crystal defects in silicon single crystal substrate | |
| JP5440564B2 (en) | Method for detecting crystal defects | |
| JP2936916B2 (en) | Quality evaluation method of silicon single crystal | |
| JP2010275147A (en) | Method for evaluating crystal defect of silicon wafer | |
| KR102661941B1 (en) | Method for evaluating of defect area of wafer | |
| TW201913129A (en) | Silicon wafer evaluation method and silicon wafer manufacturing method | |
| JP3717691B2 (en) | Silicon wafer evaluation method | |
| JP2004119446A (en) | Annealed wafer and method for manufacturing the same | |
| JP5742742B2 (en) | Metal contamination assessment method | |
| JP3690563B2 (en) | Silicon substrate evaluation method and semiconductor device manufacturing method | |
| JP2002151519A (en) | Method of manufacturing annealed wafer and annealed wafer | |
| KR100712057B1 (en) | Method for producing silicon single crystal layer and silicon single crystal layer | |
| JP5315897B2 (en) | Silicon wafer evaluation method and silicon wafer manufacturing method | |
| JP3874255B2 (en) | Evaluation method of BMD size in silicon wafer | |
| JP2004031845A (en) | Method for evaluating gettering capability | |
| JP6713493B2 (en) | Epitaxial silicon wafer manufacturing method and epitaxial silicon wafer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20240521 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20250227 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20250311 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20250324 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 7666396 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |