JP6127649B2 - Method for measuring plane orientation of single crystal substrate made of uniaxial crystal - Google Patents
Method for measuring plane orientation of single crystal substrate made of uniaxial crystal Download PDFInfo
- Publication number
- JP6127649B2 JP6127649B2 JP2013069985A JP2013069985A JP6127649B2 JP 6127649 B2 JP6127649 B2 JP 6127649B2 JP 2013069985 A JP2013069985 A JP 2013069985A JP 2013069985 A JP2013069985 A JP 2013069985A JP 6127649 B2 JP6127649 B2 JP 6127649B2
- Authority
- JP
- Japan
- Prior art keywords
- substrate
- light
- measurement light
- angle
- measurement
- 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
- 239000000758 substrate Substances 0.000 title claims description 161
- 239000013078 crystal Substances 0.000 title claims description 110
- 238000000034 method Methods 0.000 title claims description 36
- 238000005259 measurement Methods 0.000 claims description 93
- 230000003287 optical effect Effects 0.000 claims description 53
- 230000010287 polarization Effects 0.000 claims description 26
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 24
- 229910010271 silicon carbide Inorganic materials 0.000 description 19
- 239000010409 thin film Substances 0.000 description 10
- 238000002441 X-ray diffraction Methods 0.000 description 6
- 239000010453 quartz Substances 0.000 description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 5
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 3
- 238000000691 measurement method Methods 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- JMASRVWKEDWRBT-UHFFFAOYSA-N Gallium nitride Chemical compound [Ga]#N JMASRVWKEDWRBT-UHFFFAOYSA-N 0.000 description 2
- 239000006061 abrasive grain Substances 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- SWXVUIWOUIDPGS-UHFFFAOYSA-N diacetone alcohol Natural products CC(=O)CC(C)(C)O SWXVUIWOUIDPGS-UHFFFAOYSA-N 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 235000019441 ethanol Nutrition 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910021421 monocrystalline silicon Inorganic materials 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229910052594 sapphire Inorganic materials 0.000 description 1
- 239000010980 sapphire Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
Description
本発明は、一軸結晶（uniaxial crystal）からなる単結晶基板の面方位を測定する方法、及びこれに用いる測定装置に関し、詳しくは、光学的手法によって、基板の法線方向に対する結晶主軸の傾斜角度、及び、結晶主軸の傾斜方向を特定する面方位測定方法、及び、これに用いる面方位測定装置に関する。 The present invention relates to a method for measuring the plane orientation of a single crystal substrate made of a uniaxial crystal, and a measuring apparatus used therefor, and more specifically, the tilt angle of the crystal main axis with respect to the normal direction of the substrate by an optical method. Further, the present invention relates to a plane orientation measuring method for specifying the tilt direction of a crystal main axis, and a plane orientation measuring apparatus used therefor.
単結晶基板では、基板の法線方向に対する結晶主軸（炭化ケイ素ではｃ軸）の傾斜角度や、その向きに応じて、種々の物性値が異なる。前者の傾斜角度は「オフ角度」と呼ばれ、後者の向きは「オフ方向」と呼ばれる。単結晶基板の利用においては、基板特性を最大限発揮させるために、オフ角度やオフ方向を含めた最適な面方位を選択する必要がある。そのため、単結晶基板の品質項目の一つとして、この面方位に関する情報が提供されている。一般に、単結晶基板の面方位測定では、基板のオリフラに沿った方向が示す結晶方位(例えば炭化ケイ素では[11-20]方向となるように狙って加工したオリフラに沿った直線の方向)と結晶主軸を基板の表面に投影したベクトルとのなす角度で表される実際のオフ方向と、基板の法線に対する結晶主軸の傾斜角度で表されるオフ角度とを求める必要がある。特に、基板口径が6インチになった時点で、オリフラの設置方法が従来の大小２個（面方位判定が比較的容易）から単一オリフラに国際標準が変更され、単にオリフラ位置のみでは面方位特定が困難になっている。このため、オフ角度およびオフ方向を検出する方法が面方位チェックにおいて重要となってくる。 In a single crystal substrate, various physical property values vary depending on the tilt angle of the crystal main axis (c-axis in silicon carbide) with respect to the normal direction of the substrate and its orientation. The former inclination angle is called “off angle”, and the latter direction is called “off direction”. In using a single crystal substrate, it is necessary to select an optimal plane orientation including an off angle and an off direction in order to maximize the substrate characteristics. Therefore, information regarding this plane orientation is provided as one of the quality items of the single crystal substrate. Generally, in the plane orientation measurement of a single crystal substrate, the crystal orientation indicated by the direction along the orientation flat of the substrate (for example, the direction of a straight line along the orientation flat aimed at the [11-20] direction in silicon carbide) and It is necessary to obtain an actual off direction represented by an angle formed by a vector projected from the crystal principal axis on the surface of the substrate and an off angle represented by an inclination angle of the crystal principal axis with respect to the normal line of the substrate. In particular, when the board diameter is 6 inches, the orientation standard for the orientation flat has been changed from two conventional sizes (relatively easy to determine orientation) to a single orientation flat. Identification has become difficult. For this reason, a method of detecting the off angle and the off direction is important in the plane orientation check.
現在、単結晶基板の面方位測定には、主に、Ｘ線回折法が用いられている。例えば、単結晶サファイヤ基板の主面におけるオフ角度の大きさ測定したり（特許文献１の段落0048参照）、単結晶シリコン基板のオフ角方向を測定したり（特許文献２の段落0036参照）、単結晶ＧａＮ基板のオフ角度を測定したり（特許文献３の段落0060参照）など、様々な場面でＸ線回折法が利用されている。ところが、Ｘ線を使用するためには、Ｘ線作業主任者の配置やＸ線管理区域の指定が必要であることからも分るように、Ｘ線回折法は、誰でも簡単に使える手段であるとは言い難い。 Currently, the X-ray diffraction method is mainly used for measuring the plane orientation of a single crystal substrate. For example, the size of the off angle on the main surface of the single crystal sapphire substrate (see paragraph 0048 of Patent Document 1), the direction of the off angle of the single crystal silicon substrate (see Paragraph 0036 of Patent Document 2), The X-ray diffraction method is used in various situations such as measuring the off-angle of a single crystal GaN substrate (see paragraph 0060 of Patent Document 3). However, in order to use X-rays, the X-ray diffraction method is an easy-to-use method, as it can be seen from the fact that it is necessary to designate the X-ray work manager and specify the X-ray management area. It is hard to say that there is.
そこで、特許文献４では、水晶薄膜における屈折率の異方性に着目して、Ｘ線を使わずに、水晶薄膜の法線（成長方向）と水晶薄膜の光学軸とのなす角度、及び、光学軸の傾斜方向を求める方法を提案している。すなわち、この特許文献４で提案する方法では、水晶薄膜の法線と水晶薄膜の光学軸とのなす角度をほぼ４５°に設定した上で、分光器を出た光が偏光子、水晶薄膜、及び検光子を通過した後の光量を求め、検光子を回転させた際の透過光量の変化をフーリエ変換して算出した式と比較することで、水晶薄膜の法線と水晶薄膜の光学軸とのなす角度、及び、光学軸を水晶薄膜に投影した線と水晶薄膜の外形基準辺とのなす角度を求めるようにしている。しかしながら、この方法の適用にあたっては、位相差を利用した測定であることから、被測定物の厚さに制約がある。そのため、バルクの単結晶基板における面方位を測定するのに十分相応しい方法であるとは言えない。 Therefore, in Patent Document 4, paying attention to the anisotropy of the refractive index in the quartz thin film, the angle formed between the normal (growth direction) of the quartz thin film and the optical axis of the quartz thin film without using X-rays, and A method for determining the tilt direction of the optical axis is proposed. That is, in the method proposed in Patent Document 4, the angle formed between the normal line of the crystal thin film and the optical axis of the crystal thin film is set to about 45 °, and the light emitted from the spectroscope is converted into a polarizer, a crystal thin film, Then, the amount of light after passing through the analyzer is obtained, and the change in the amount of transmitted light when the analyzer is rotated is compared with the formula calculated by Fourier transform, so that the normal line of the crystal thin film and the optical axis of the crystal thin film And the angle formed by the line formed by projecting the optical axis onto the quartz thin film and the outer reference edge of the quartz thin film. However, in applying this method, since the measurement uses a phase difference, the thickness of the object to be measured is limited. Therefore, it cannot be said that the method is sufficiently suitable for measuring the plane orientation in a bulk single crystal substrate.
また、特許文献５には、特定波長の光源と偏光板とを組み合わせることで、単結晶基板の面内における結晶方位を求める方法が開示されている。しかしながら、この方法では、結晶主軸（ｃ軸）が基板の法線方向に対して傾いている場合には、その傾斜角度まで特定することはできず、現在、主流であるようなオフ角度を持った基板の面方位を測定するのには不適である。 Patent Document 5 discloses a method for obtaining a crystal orientation in a plane of a single crystal substrate by combining a light source having a specific wavelength and a polarizing plate. However, in this method, when the crystal main axis (c-axis) is tilted with respect to the normal direction of the substrate, it is not possible to specify the tilt angle, and there is an off angle that is currently mainstream. It is not suitable for measuring the plane orientation of the substrate.
本発明は、上記のような従来技術を鑑みてなされたものであり、光学的手法によって、一軸結晶からなる単結晶基板の面方位を、正確かつ簡便に測定することができる方法を提供することを目的とする。また、本発明は、上記方法に用いる面方位測定装置を提供することを目的とする。 The present invention has been made in view of the prior art as described above, and provides a method capable of accurately and simply measuring the plane orientation of a single crystal substrate made of a uniaxial crystal by an optical method. With the goal. Moreover, an object of this invention is to provide the surface orientation measuring apparatus used for the said method.
本発明者等は、バルク単結晶基板の面方位を測定するのに好適な手段について鋭意検討した結果、一軸結晶における光学的異方性を利用して、すなわち、一軸結晶からなる単結晶基板に任意の方向から光を入射させた際、光の屈折率が結晶主軸に固有な屈折率の合成値となって、光の入射方向の関数になることを利用することで、Ｘ線回折法によらずに、しかも、測定対象である基板の面方位や、その厚さに制約を受けることなく、正確かつ簡便に面方位を特定できることを見出し、本発明を完成するに至った。 As a result of intensive studies on means suitable for measuring the plane orientation of a bulk single crystal substrate, the present inventors have made use of optical anisotropy in a uniaxial crystal, that is, a single crystal substrate composed of a uniaxial crystal. By making use of the fact that when light is incident from any direction, the refractive index of the light becomes a composite value of the refractive index inherent to the crystal main axis and becomes a function of the incident direction of the light. Independently, the present inventors have found that the plane orientation can be specified accurately and simply without being restricted by the plane orientation and thickness of the substrate to be measured, and the present invention has been completed.
すなわち、本発明の要旨は、次のとおりである。
(１) 一軸結晶からなり、オリフラを備えた単結晶基板の面方位を測定する方法であって、
ｉ）偏光子から取り出された直線偏光を測定光とし、該測定光が、検光子を介して、光検出器で検出される光量がゼロになるようにした状態で、
偏光子と検光子との間に測定対象の基板を配置すると共に、該基板の法線方向に沿って測定光が入射されるようにして、
光検出器側で検出される光量がゼロになるように、測定光の光軸を中心に基板を回転させて、オリフラが示す結晶方位と測定光の偏波面とのなす角を測定して、結晶主軸の傾斜方向を求め、
ii）次いで、基板を測定光の光路から外して、測定光の光軸を中心に偏光子と検光子とをそれぞれ同方向に０°超９０°未満の範囲内の角度で回転させた上で、再度光検出器側で検出される光量がゼロになるように調整して、ｉ）の測定後の回転角度を維持したまま基板を測定光の光路に再配置し、測定光の進行方向に対して該基板を前後に傾けて、基板からの出射光の偏波面が基板に入射される前の測定光の偏波面と揃う位置で、基板の法線と測定光の光軸とのなす角を測定して、結晶主軸の傾斜角度を求める、
ことを特徴とする一軸結晶からなる単結晶基板の面方位測定方法。
(２) ii）の測定において測定光の光軸を中心に偏光子と検光子とを回転させる角度が４５°である、(１)に記載の一軸結晶からなる単結晶基板の面方位測定方法。
(３) 一軸結晶からなる単結晶基板が、炭化ケイ素（SiC）単結晶基板であることを特徴とする、(１)又は(２)に記載の一軸結晶からなる単結晶基板の面方位測定方法。
That is, the gist of the present invention is as follows.
(1) A method for measuring the plane orientation of a single crystal substrate made of a uniaxial crystal and provided with an orientation flat,
i) With the linearly polarized light extracted from the polarizer as the measurement light, the measurement light is in a state where the amount of light detected by the photodetector through the analyzer is zero,
While arranging the substrate to be measured between the polarizer and the analyzer, the measurement light is incident along the normal direction of the substrate,
Rotate the substrate around the optical axis of the measurement light so that the amount of light detected on the photodetector side is zero, measure the angle between the crystal orientation shown by the orientation flat and the polarization plane of the measurement light, Find the tilt direction of the crystal main axis,
ii) Next, after removing the substrate from the optical path of the measurement light and rotating the polarizer and the analyzer around the optical axis of the measurement light in the same direction at an angle in the range of more than 0 ° and less than 90 °, respectively. Adjust again so that the amount of light detected on the photodetector side becomes zero, and re-arrange the substrate in the optical path of the measurement light while maintaining the rotation angle after the measurement in i), in the traveling direction of the measurement light The angle formed between the normal of the substrate and the optical axis of the measurement light at a position where the polarization plane of the light emitted from the substrate is aligned with the polarization plane of the measurement light before being incident on the substrate by tilting the substrate back and forth To determine the tilt angle of the crystal main axis,
A method of measuring a plane orientation of a single crystal substrate made of a uniaxial crystal.
(2) The method for measuring the plane orientation of a single crystal substrate made of a uniaxial crystal according to (1), wherein the angle at which the polarizer and the analyzer are rotated about the optical axis of the measurement light in the measurement of ii) is 45 ° .
(3) The method for measuring the plane orientation of a single crystal substrate comprising a uniaxial crystal according to (1) or (2), wherein the single crystal substrate comprising a uniaxial crystal is a silicon carbide (SiC) single crystal substrate .
本発明によれば、光学的手法によって、一軸結晶からなる単結晶基板の面方位を正確に測定することができる。そのため、Ｘ線作業主任者の配置やＸ線管理区域の指定など、Ｘ線の安全利用にあたって細心の注意が求められるＸ線回折法に比べて、遥かに簡便に面方位を特定することができる。また、本発明によれば、測定対象の基板が特定の厚みに制限されたり、その面方位に制約を受けることがないため、一軸結晶からなる種々の単結晶基板に対して、広範囲に適用することができる。 According to the present invention, the plane orientation of a single crystal substrate made of a uniaxial crystal can be accurately measured by an optical method. Therefore, it is possible to specify the plane orientation much more easily than the X-ray diffraction method that requires careful attention in the safe use of X-rays, such as the arrangement of the X-ray work supervisor and the designation of the X-ray management area. . In addition, according to the present invention, the substrate to be measured is not limited to a specific thickness and is not restricted by the plane orientation, and thus can be widely applied to various single crystal substrates made of uniaxial crystals. be able to.
以下、本発明について、図面を用いながら詳細に説明する。
本発明においては、一軸結晶からなる単結晶基板の面方位測定を、ｉ）単結晶基板が備える結晶主軸Ｌを基板の表面に投影したベクトルが、基板のオリフラが示す結晶方位ＯＦ（以下、「オリフラ方位」と言う場合がある）に対して、どの程度の角度を有するのか測定する段階（第一の測定段階）と、ii）基板の法線ｎに対する結晶主軸の傾斜角度を測定する段階（第二の測定段階）との、２段階に分けて行う。このうち、ｉ）の段階で求める角度は、図１に示すなす角Φ（ファイ）であり、これは、いわゆる「オフ方向」と呼ばれるものに相当する。一方、ii）の段階で求める角度は、図１に示すなす角θであり、これは、いわゆる「オフ角度」と呼ばれるものに相当する。
Hereinafter, the present invention will be described in detail with reference to the drawings.
In the present invention, the plane orientation measurement of a single crystal substrate made of a uniaxial crystal is performed. I) A vector obtained by projecting the crystal principal axis L provided on the single crystal substrate onto the surface of the substrate is a crystal orientation OF (hereinafter, “ Measuring the degree of the angle with respect to the normal n of the substrate (step 1), It is divided into two stages, the second measurement stage). Of these, the angle obtained in the step i) is an angle Φ (phi) shown in FIG. 1, which corresponds to what is called an “off direction”. On the other hand, the angle obtained in the stage ii) is the angle θ formed in FIG. 1, which corresponds to what is called an “off angle”.
オフ方向は単結晶基板の素材によってそれぞれ特有の結晶方位になるように加工されるが、例えば炭化ケイ素（SiC）においては、一般にオフ方向として［１１−２０］方向を選ぶことに決まっている。炭化ケイ素は通常[０００１]方向であるｃ軸が基板面に対して傾斜角度（オフ角度）が付くようにして加工するが、その場合、切断した基板には必ずC面とSi面が表裏になるような基板が切り出される。C面とSi面は物理的特性が異なるため、基板利用の際には必ず面方位が分かるようにする必要がある。SiCでは口径４インチまでの基板では、この面方位が確認できるように加工することになっていた。すなわち基板加工の際には、ｃ軸が傾いている方向（オフ方向）を直線で表すために、オフ方向に平行に基板の端に直線部分を設けることになっている。この直線部分が「オリフラ」（オリエンテーション・フラットの略称）と呼ばれる部分である。SiCでは口径４インチまでの基板ではさらに面方位が分かるように、オフ方向を表すオリフラを大きく付け、それに対して基板の周方向に90°ずれた位置に長さがやや短い「小オリフラ」を付けていた。この「小オリフラ」が「大オリフラ」に対して周方向で「左に90°」の位置に見える面が必ず「Si面」となるように加工することが国際標準で決められていた。しかし、口径６インチSiC基板においてはSi大口径基板と同一仕様である、オリフラを1箇所のみ付ける「単一オリフラ」が国際標準仕様となり、このためにオリフラの位置のみでは面方位を特定することができなくなった。この場合、基板を正面から見た際にオリフラ位置が下になっている時に、従来と同じ仕様、すなわち小オリフラが大オリフラに対して周方向で左上90°に位置するときに、ｃ軸が小オリフラの方向へ傾斜（オフ）している面が「Si面」となるように加工することが定められている。このため、単一オリフラでもオフ方向測定により面方位を特定することが可能となる。
このため、オリフラ方向および角度測定の際にはこのオリフラを特定の方位にセットして測定することが便利であり、本発明でもそのような手法を用いる。
The off direction is processed so as to have a specific crystal orientation depending on the material of the single crystal substrate. For example, in silicon carbide (SiC), it is generally decided to select the [11-20] direction as the off direction. Silicon carbide is processed so that the c-axis, which is usually the [0001] direction, has an inclination angle (off angle) with respect to the substrate surface. A substrate is cut out. Since the physical characteristics of the C plane and Si plane are different, it is necessary to make sure that the plane orientation is known when using the substrate. In SiC, substrates with a diameter of up to 4 inches were processed so that this plane orientation could be confirmed. That is, when processing the substrate, in order to represent the direction in which the c-axis is inclined (off direction) by a straight line, a straight line portion is provided at the end of the substrate parallel to the off direction. This straight line portion is a portion called “orientation flat” (abbreviation of orientation flat). For SiC substrates with a diameter of up to 4 inches, the orientation flat indicating the off-direction is increased so that the plane orientation can be understood. On the other hand, the “small orientation flat” is slightly shorter at a position shifted by 90 ° in the circumferential direction of the substrate. It was attached. It was decided by the international standard that this “small orientation flat” should be processed so that the surface that appears “90 ° to the left” in the circumferential direction with respect to the “large orientation flat” would always be the “Si face”. However, the 6-inch SiC substrate has the same specifications as the Si large-diameter substrate, and the “single orientation flat” with only one orientation flat is the international standard specification. For this reason, the plane orientation must be specified only by the orientation flat position. Is no longer possible. In this case, when the orientation flat position is downward when the substrate is viewed from the front, the c-axis is the same as the conventional specification, that is, when the small orientation flat is positioned 90 ° in the upper left in the circumferential direction with respect to the large orientation flat. It is specified that the surface inclined (off) in the direction of the small orientation flat becomes a “Si surface”. For this reason, even with a single orientation flat, it is possible to specify the plane orientation by off-direction measurement.
For this reason, when measuring the orientation flat and angle, it is convenient to set the orientation flat in a specific direction for measurement, and such a method is also used in the present invention.
本発明における測定に際しては、図２に示すような装置構成からなる測定装置を用いるようにする。すなわち、光源１、偏光子３、検光子６、及び光検出器７を用いるようにして、偏光子３を通して、光源１からの光を直線偏光にして測定光８とし、この測定光８が、検光子６を介して、光検出器７で検出される光量がゼロになるように、測定装置を構成する。ここで、光源１については、例えば、Ｈｇランプ、ハロゲンランプ等の自然光を用いることもでき、Ｈｅ−Ｎｅレーザー等のレーザー光を用いることもできる。但し、自然光を用いる場合には、バンドパスフィルター等の分光器２で単色化して、偏光子３に入射させるようにするのが好ましい。また、偏光子３及び検光子６については、公知の偏光板等を用いることができ、光検出器７については、例えば、光量を信号強度として検出することができるような公知のものが使用可能である。なお、光検出器７で検出される光量がゼロになるようにするとは、偏光子３の偏光方向と検光子６の偏光方向とが直交する状態を意味する。 In the measurement according to the present invention, a measurement apparatus having the apparatus configuration as shown in FIG. 2 is used. That is, using the light source 1, the polarizer 3, the analyzer 6, and the photodetector 7, the light from the light source 1 is converted into linearly polarized light through the polarizer 3 to obtain the measurement light 8. The measuring device is configured so that the amount of light detected by the photodetector 7 becomes zero via the analyzer 6. Here, for the light source 1, for example, natural light such as an Hg lamp and a halogen lamp can be used, and laser light such as a He—Ne laser can also be used. However, when natural light is used, it is preferable that the light is made monochromatic by a spectroscope 2 such as a bandpass filter and incident on the polarizer 3. For the polarizer 3 and the analyzer 6, a known polarizing plate or the like can be used. For the photodetector 7, for example, a known one that can detect the amount of light as the signal intensity can be used. It is. In addition, making the light quantity detected by the photodetector 7 zero means a state in which the polarization direction of the polarizer 3 and the polarization direction of the analyzer 6 are orthogonal to each other.
先ず、ｉ）の測定段階では、図２に示す装置構成にした測定装置において、偏光子３と検光子６との間に、試料ステージ５を用いて測定対象の基板４を配置する。その際、基板４のオリフラ4aが鉛直線に沿うように位置決めする。すなわち、図４（ａ）に示すように、紙面の上下方向を鉛直線とすれば、それにオリフラ4aが沿うようにする。このとき、オリフラ4aは左右どちらの位置にあっても構わない。次に、基板４の法線方向ｎに沿って測定光８が入射されるように、測定光８の進行方向（光軸8a）を基板４の法線方向ｎに揃えるようにする。ここで、試料ステージ５は、測定光に対して上記のような位置関係で基板を保持して、基板に入射した測定光を検光子側に透過させることができるものであれば良く、公知のものを使用することができる。また、後述するように、測定光の光軸を中心に基板を回転させることができる回転機構や、第二の測定段階で測定光の進行方向前後に基板を傾斜させることができる傾斜機構を備えたものを使用するのが好適である。 First, in the measurement stage i), the measurement target substrate 4 is arranged between the polarizer 3 and the analyzer 6 using the sample stage 5 in the measurement apparatus having the apparatus configuration shown in FIG. At that time, the orientation flat 4a of the substrate 4 is positioned along the vertical line. That is, as shown in FIG. 4 (a), if the vertical direction of the paper is a vertical line, the orientation flat 4a is along the vertical line. At this time, the orientation flat 4a may be in either the left or right position. Next, the traveling direction (optical axis 8 a) of the measurement light 8 is aligned with the normal direction n of the substrate 4 so that the measurement light 8 is incident along the normal direction n of the substrate 4. Here, the sample stage 5 is not limited as long as it can hold the substrate in the positional relationship as described above with respect to the measurement light and transmit the measurement light incident on the substrate to the analyzer side. Things can be used. In addition, as will be described later, a rotation mechanism capable of rotating the substrate around the optical axis of the measurement light and a tilt mechanism capable of tilting the substrate before and after the traveling direction of the measurement light in the second measurement stage are provided. It is preferable to use the same one.
基板４の法線方向ｎに沿って入射された測定光８は、一軸結晶からなる単結晶基板の屈折率の方位依存性により、検光子６側には楕円偏光状態で出射される。そこで、図４（ａ）に示すように、基板４の光学主軸に対して、測定光９である直線偏光の偏波面8bが平行に入射されるように、測定光８の光軸8aを中心に基板４を回転させて（図中の両矢印方向）、光検出器側で検出される光量が再びゼロになる位置を探す。すなわち、図３に示したように、楕円偏光状態をベクトル表記した際の楕円９の短軸方向9a又は長軸方向9bは、基板の光学主軸に対応し、この長軸又は短軸方向と基板に入射される測定光の偏波面8bとが一致すると、基板から出射する光は直線偏光になるため、検光子を透過することができなくなる。そのため、図４（ｂ）に示すように、光検出器側で検出される光量がゼロになった位置で、基板４のオリフラ方位ＯＦと、基板４に入射された測定光の偏波面8bとのなす角αを測定すれば、このなす角αは、先に説明した図１に示したなす角Φに該当するため、基板の表面における結晶主軸の傾斜方向を特定することができる。 The measurement light 8 incident along the normal direction n of the substrate 4 is emitted in an elliptically polarized state toward the analyzer 6 due to the orientation dependency of the refractive index of the single crystal substrate made of a uniaxial crystal. Therefore, as shown in FIG. 4A, the optical axis 8a of the measurement light 8 is centered so that the polarization plane 8b of the linearly polarized light that is the measurement light 9 is incident on the optical principal axis of the substrate 4 in parallel. Then, the substrate 4 is rotated (in the direction of the double arrow in the figure), and a position where the light amount detected on the photodetector side becomes zero again is searched. That is, as shown in FIG. 3, the short axis direction 9a or the long axis direction 9b of the ellipse 9 when the elliptical polarization state is expressed as a vector corresponds to the optical principal axis of the substrate. When the polarization plane 8b of the measurement light incident on the light source coincides with the light, the light emitted from the substrate becomes linearly polarized light and cannot pass through the analyzer. Therefore, as shown in FIG. 4B, the orientation flat direction OF of the substrate 4 and the polarization plane 8b of the measurement light incident on the substrate 4 at the position where the light amount detected on the photodetector side becomes zero. If the angle α is measured, the formed angle corresponds to the angle Φ shown in FIG. 1 described above, so that the tilt direction of the crystal main axis on the surface of the substrate can be specified.
次に、ii）の測定段階では、なす角Φを求めた基板の回転位置のまま、すなわち回転機構を有した試料ステージごと、いったん測定光８の光路から外し、次に、ｉ）の測定の設定に対して、測定光８の光軸を中心に偏光子３及び検光子６を最初の設定に対して０°超９０°未満の範囲内でそれぞれ同じ方向に回転させ、その位置で再度調整して、偏光子３を通して光源１からの光を直線偏光にした測定光８が、検光子６を介して、光検出器７で検出される光量がゼロになるように、測定装置を構成する。この時の回転させる角度については当初の角度から前記したように０°超９０°未満の範囲内であれば（いずれの方向でも）任意の角度で良いが、次回測定において調整時にもっとも検出光の変化が大きくなり判別がより容易となる点において４５°に設定することがより好適である。 Next, in the measurement stage of ii), the angle Φ formed is kept at the rotation position of the substrate, that is, the sample stage having the rotation mechanism is once removed from the optical path of the measurement light 8, and then the measurement of i) is performed. With respect to the setting, the polarizer 3 and the analyzer 6 are rotated in the same direction within the range of more than 0 ° and less than 90 ° with respect to the initial setting around the optical axis of the measuring light 8 and adjusted again at that position. Then, the measuring device is configured so that the measurement light 8 obtained by linearly polarizing the light from the light source 1 through the polarizer 3 has zero light amount detected by the photodetector 7 through the analyzer 6. . The rotation angle at this time may be any angle (in any direction) as long as it is within the range of more than 0 ° and less than 90 ° from the initial angle as described above. It is more preferable to set the angle to 45 ° in that the change becomes large and the discrimination becomes easier.
この調整を行った後、再度ｉ）で回転角度を決定したままの角度を維持した状態で試料ステージごと基板を光路に戻す。この時点で、ｉ）の測定時には基板から出射された光が光検出器７で検出される光量ゼロとなっていた状態が、偏光子の設定を変えたことにより再び検出されるようになっている。 After this adjustment, the substrate is returned to the optical path together with the sample stage while maintaining the rotation angle determined in i) again. At this time, the state in which the light emitted from the substrate is zero when the light is detected by the photodetector 7 at the time of measurement i) is detected again by changing the setting of the polarizer. Yes.
次いで、基板に入射した測定光の偏波面に対して基板を傾けるようにして、すなわち、図５に示すように、最初の測定において確認した「オフ方向」に沿った方向を維持したままで、測定光８の光軸8aに対して基板を回転させずに、測定光の光軸8aと基板との交点を通り、図５での紙面に垂直に向かう回転軸ｐを中心にして、光軸を通る基板の法線方向のベクトルｎの先端が上下するように、基板４の上端と下端を測定光の進行方向前後に傾斜させるようにして、基板４から出射する光の偏波面が、基板に入射する測定光８の偏波面と一致する位置を求める。 Next, the substrate is tilted with respect to the polarization plane of the measurement light incident on the substrate, that is, while maintaining the direction along the “off direction” confirmed in the first measurement, as shown in FIG. Without rotating the substrate with respect to the optical axis 8a of the measurement light 8, the optical axis passes through the intersection of the optical axis 8a of the measurement light and the substrate, and the rotation axis p is perpendicular to the paper surface in FIG. The polarization plane of the light emitted from the substrate 4 is such that the upper end and lower end of the substrate 4 are inclined forward and backward in the traveling direction of the measurement light so that the tip of the vector n in the normal direction of the substrate passing through A position that coincides with the plane of polarization of the measurement light 8 incident on is obtained.
ここで、基板４からの出射光の偏波面が測定光の偏波面と揃う位置で屈折率の異方性が消失していれば（すなわち屈折率が等方的となれば）、一軸結晶からなる基板の光学主軸と平行に測定光の偏波面が入射する状態に相当していることになる。そのため、このときの基板の法線ｎと、測定光の光軸8aとのなす角βを測定すれば、このなす角βが、先に説明した図１に示したなす角θに該当するため、基板の法線ｎに対する結晶主軸の傾斜角度を特定することができる。 Here, if the anisotropy of the refractive index disappears at the position where the plane of polarization of the light emitted from the substrate 4 is aligned with the plane of polarization of the measurement light (that is, if the refractive index is isotropic), then from the uniaxial crystal This corresponds to a state in which the plane of polarization of the measurement light is incident in parallel to the optical principal axis of the substrate. Therefore, if the angle β formed between the normal n of the substrate at this time and the optical axis 8a of the measuring light is measured, the formed angle β corresponds to the angle θ shown in FIG. 1 described above. The tilt angle of the crystal main axis with respect to the normal line n of the substrate can be specified.
基板から出射した光が直線偏光であることを確認するためには、例えば、偏光子３を交換して、これまで使用した測定光とは別の任意の直線偏光を基板に入射させるようにし、基板からの出射光の偏波面が、任意の直線偏光の偏波面と揃うことを確認する（つまり、前に使用した直線偏光の時と同様に、光検出器８での光量がゼロになる）ようにしても良い。 In order to confirm that the light emitted from the substrate is linearly polarized light, for example, the polarizer 3 is replaced so that any linearly polarized light different from the measurement light used so far is incident on the substrate, Confirm that the plane of polarization of the light emitted from the substrate is aligned with the plane of polarization of any linearly polarized light (that is, the amount of light at the photodetector 8 becomes zero, as in the case of the linearly polarized light used previously). You may do it.
また、ii）の測定においては、図２の装置構成における基板４と検光子６との間に、「１／４波長板」を配置すると共に、この１／４波長板の光学主軸が、測定光８の偏波面に対して平行又は垂直になるようにして、測定装置を構成する手法も適用可能である。この手法は、セナルモン法に準拠するものであり、１／４波長板は公知のものを使用することができる。この場合は試料ステージとして、基板を任意の角度に回転させた際、その回転角度を固定したままで回転した位置において前記した測定手法と同様に基板が前後方向に傾斜させられるようなステージ構成としておく必要がある。 In the measurement of ii), a “¼ wavelength plate” is arranged between the substrate 4 and the analyzer 6 in the apparatus configuration of FIG. 2, and the optical principal axis of this ¼ wavelength plate is measured. A method of configuring the measuring device so as to be parallel or perpendicular to the polarization plane of the light 8 is also applicable. This method is based on the Senalmon method, and a known quarter wave plate can be used. In this case, as the sample stage, when the substrate is rotated to an arbitrary angle, the stage is configured such that the substrate is tilted in the front-rear direction at the position rotated with the rotation angle fixed, as in the measurement method described above. It is necessary to keep.
この１／４波長板を使用する時は、ｉ）の測定を行った後に、その角度から測定光の光軸を中心に基板を４５°さらに回転させる。こうすることでｉ）の測定にて光検出器７にて検出できる光量がゼロとなっていたのが再び検出されるような配置となる。このような配置にした上で上記したように１／４波長板を配置し、それから測定光の進行方向に対して基板を前後させると、やはり基板の持つ光学主軸が測定光８の光軸8aが完全に一致した場合のみ、再び光検出器７にて検出できる光量がゼロとなる。ここで同じように基板の法線ｎと、測定光の光軸8aとのなす角βを測定すれば、このなす角βが、先に説明した図１に示したなす角θに該当するため、基板の法線ｎに対する結晶主軸の傾斜角度を特定することができる。 When this quarter-wave plate is used, after the measurement of i) is performed, the substrate is further rotated 45 ° from the angle around the optical axis of the measurement light. By doing so, the arrangement is such that the amount of light that can be detected by the photodetector 7 in the measurement of i) is detected again. When the quarter-wave plate is arranged as described above and the substrate is moved back and forth with respect to the traveling direction of the measurement light, the optical principal axis of the substrate is also the optical axis 8a of the measurement light 8. Only when they completely match, the amount of light that can be detected by the photodetector 7 again becomes zero. Similarly, if the angle β formed between the normal n of the substrate and the optical axis 8a of the measurement light is measured, the angle β corresponds to the angle θ shown in FIG. 1 described above. The tilt angle of the crystal main axis with respect to the normal line n of the substrate can be specified.
この場合の利点は基板をセットした試料ステージを光路から外すという作業を省けることであるが、その代わりに試料ステージとしてｘｙｚ座標のいずれにも独立して可動できるような機構にすることが必要であり、その点では先に示した手法の方が簡便となることもあり得る。いずれの手法も適用可能であり、便宜を考えて選択することができる。 The advantage in this case is that the work of removing the sample stage on which the substrate is set from the optical path can be omitted. Instead, it is necessary to provide a mechanism that can move independently of any xyz coordinates as the sample stage. In that respect, the method described above may be simpler. Either method is applicable and can be selected for convenience.
本発明の方法は、一軸結晶（uniaxial crystal）からなる単結晶基板であれば、特に制約なく面方位を測定することができ、炭化珪素（SiC）、窒化ガリウム（GaN）等をはじめとする種々の単結晶基板の表面における結晶主軸の傾斜方向、及び、基板の法線ｎに対する結晶主軸の傾斜角度を特定することができる。 The method of the present invention can measure the plane orientation without any particular limitation as long as it is a single crystal substrate made of a uniaxial crystal, and includes various types including silicon carbide (SiC) and gallium nitride (GaN). The tilt direction of the crystal principal axis on the surface of the single crystal substrate and the tilt angle of the crystal principal axis with respect to the normal line n of the substrate can be specified.
以下、実施例に基づき、本発明を具体的に説明するが、本発明は以下の内容に制限されるものではない。 EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not restrict | limited to the following content.
［実施例１］
一軸結晶である炭化珪素（SiC）単結晶基板に対して、本発明の面方位測定方法により、結晶主軸の傾斜方向、及び基板の法線に対する結晶主軸の傾斜角度を求めた。測定対象のSiC単結晶基板は、４Ｈ型のポリタイプを有して、その表面（主面）は（０００１）であり（すなわち結晶主軸は＜０００１＞であり）、口径は３インチ、厚さは３００μｍである。この基板は、以下のようにして、窒素ドープによりｎ型化したインゴットから切り出されたものであり、マルチワイヤソーを用いたスライス化では、ワイヤーは必ずしも正確に真っ直ぐに進むとは限らないため、研磨完了後、個々の基板について、基板の法線方向に対する結晶方位を確認する必要がある。
[Example 1]
With respect to a silicon carbide (SiC) single crystal substrate that is a uniaxial crystal, the tilt direction of the crystal principal axis and the tilt angle of the crystal principal axis with respect to the normal line of the substrate were determined by the plane orientation measurement method of the present invention. The SiC single crystal substrate to be measured has a 4H type polytype, its surface (principal surface) is (0001) (that is, the crystal principal axis is <0001>), the diameter is 3 inches, and the thickness Is 300 μm. This substrate is cut out from an n-type ingot by nitrogen doping as follows, and in slicing using a multi-wire saw, the wire does not always go straight and accurate. After completion, it is necessary to confirm the crystal orientation with respect to the normal direction of the substrate for each substrate.
先ず、Ｘ線回折装置を用いて、インゴットをスライスする際の切り出し方位が［１１−２０］方向に４．０°、［１−１００］方向に０．０°（意図的なオフ化なし）となるように基準面を研削した。次いで、Ｘ線回折装置を用いて方位を定め、［１１−２０］方向に沿うオリフラの研削を行った。これらの外形加工を行った後、マルチワイヤソーを用いてインゴットを切断し、スライス化した。これをダイヤモンド砥粒の粒度を順次細かくしながら、粗ＬＡＰ、仕上げＬＡＰ、鏡面研磨の順に加工し、表面を鏡面化した。研磨後は、エチルアルコール、アセトン、イソプロピルアルコールの順に、超音波洗浄機を用いて研磨砥粒の残さを除去した。次いで、Ｎ2ガンのブローによって乾燥させ、SiC単結晶基板を得た。 First, using an X-ray diffractometer, the cut-out orientation when slicing an ingot is 4.0 ° in the [11-20] direction and 0.0 ° in the [1-100] direction (no intentional turn-off) The reference surface was ground so that Next, the orientation was determined using an X-ray diffractometer, and the orientation flat along the [11-20] direction was ground. After performing these external shapes, the ingot was cut and sliced using a multi-wire saw. This was processed in the order of rough LAP, finishing LAP, and mirror polishing in order to finer the grain size of the diamond abrasive grains, and the surface was mirror-finished. After polishing, the residue of abrasive grains was removed using an ultrasonic cleaner in the order of ethyl alcohol, acetone, and isopropyl alcohol. Next, the substrate was dried by blowing N 2 gun to obtain a SiC single crystal substrate.
本発明に係る実施例１の測定では、先ず、図２に示した測定装置を用いて、上記で得られたSiC単結晶基板について、オリフラ方位に対する結晶主軸の傾斜方位を測定した。この測定装置では、光源１としてＨｇランプ（ウシオ社製；低圧ＵＶランプ ＵＬＯ-６ＤＱ）を用い、バンドパスフィルター２で波長５４６．１ｎｍの輝線を取り出し、偏光子３（メレスグリオ社製；バンドパス干渉フィルタ Ｆ１０-546.1-4-25.0Ｍ）に入射させて測定光８とした。SiC単結晶基板４を試料ステージ５（中央精機社製；透過型微動回転ステージ ＲＳ-211Ｔおよび傾斜ステージ （±８°） ＴＳ-Ｃ611）に設置する前に、偏光子３から取り出された測定光が、検光子６（メレスグリオ社製；バンドパス干渉フィルタ Ｆ１０-546.1-4-25.0Ｍ）を介して、光検出器７（浜松ホトニクス社製；フォトダイオードモジュール Ｃ10439-03）で検出される光強度がゼロになることを確認した。 In the measurement of Example 1 according to the present invention, first, the tilt orientation of the crystal main axis with respect to the orientation flat orientation was measured for the SiC single crystal substrate obtained above using the measuring apparatus shown in FIG. In this measuring apparatus, an Hg lamp (made by Ushio Corp .; low-pressure UV lamp ULO-6DQ) is used as the light source 1, and an emission line having a wavelength of 546.1 nm is extracted by the bandpass filter 2, and a polarizer 3 (Meres Griot Corp .; bandpass interference). The measurement light 8 was made incident on the filter F10-546.1-4-25.0M). Measurement light extracted from the polarizer 3 before placing the SiC single crystal substrate 4 on the sample stage 5 (manufactured by Chuo Seiki Co., Ltd .; transmission-type fine rotation stage RS-211T and tilt stage (± 8 °) TS-C611) Is detected by the photodetector 7 (manufactured by Hamamatsu Photonics Co., Ltd .; photodiode module C10439-03) through the analyzer 6 (manufactured by Melles Griot; bandpass interference filter F10-546.1-4-25.0M). Was confirmed to be zero.
そして、SiC単結晶基板４の法線方向ｎに沿って測定光８が入射されるように、試料ステージ５にSiC単結晶基板４のオリフラ4aが鉛直線に沿うように（図４（ａ）に示したように、基板４を正面から見てオリフラ4aが左に円の角度で90°の位置となるように）取り付けたところ、光学異方性により、光検出器８で検出される光強度はゼロでない有限値となった。次いで、SiC単結晶基板４を載せた試料ステージ５ごと、測定光８の光軸8aの回りに回転させて、光検出器７で検出される光強度がゼロとなるようにした。このとき、試料ステージ５の角度目盛を用いてオリフラと測定光８の偏波面8bとのなす角を測定したところ０．１°であり、基板４を回転させた向きから、オリフラ（[11-20]）は、オリフラを左に位置させた際に上となる方向（[1-100]方向に相当）に０．１°ずれていることが分った。 Then, the orientation flat 4a of the SiC single crystal substrate 4 is placed along the vertical line on the sample stage 5 so that the measurement light 8 is incident along the normal direction n of the SiC single crystal substrate 4 (FIG. 4A). When the substrate 4 is viewed from the front and the orientation flat 4a is attached to the left so that the circular angle is 90 °, the light detected by the photodetector 8 due to optical anisotropy. The intensity was a non-zero finite value. Next, the sample stage 5 on which the SiC single crystal substrate 4 was placed was rotated around the optical axis 8a of the measurement light 8 so that the light intensity detected by the photodetector 7 became zero. At this time, the angle formed between the orientation flat and the polarization plane 8b of the measuring light 8 was measured using the angle scale of the sample stage 5, and found to be 0.1 °, and the orientation flat ([11- 20]) was found to be off by 0.1 ° in the upward direction (corresponding to the [1-100] direction) when the orientation flat was positioned to the left.
次に、SiC単結晶基板４の法線ｎに対する結晶主軸の傾斜角度を測定した。オリフラ方向測定時に回転させた基板４の回転角度はそのままで基板４を試料ステージごと（基板はステージにセットしたままで外さない）測定光の光路から外した。次に偏光子３と検光子６を同方向に４５°回転させた上で、再度光検出器側で検出される光量がゼロになるように調整した。その後、先に試料ステージごと外していた基板４をそのまま試料ステージごと再び光路に再配置した。 Next, the tilt angle of the crystal principal axis with respect to the normal line n of the SiC single crystal substrate 4 was measured. The substrate 4 rotated at the time of orientation flat direction measurement was kept as it was, and the substrate 4 was removed from the optical path of the measurement light together with the sample stage (the substrate was left on the stage). Next, after the polarizer 3 and the analyzer 6 were rotated by 45 ° in the same direction, the light amount detected again on the photodetector side was adjusted to be zero. Thereafter, the substrate 4 previously removed along with the sample stage was rearranged again in the optical path as it was along with the sample stage.
そして、図５に示したように、測定光の光軸8aと基板４との交点を通り、紙面に対して垂直である回転軸ｐを中心にして、光軸を通る基板の法線方向のベクトルｎの先端が上下するように、基板４の上端と下端を測定光８の進行方向前後に傾斜させるようにして、基板４を透過した測定光８の偏波面の回転状況を調べた。ある傾斜角度のところで、基板４を透過した測定光８の偏波面が、基板４に入射する測定光８の偏波面と一致して回転がない状態となった。 As shown in FIG. 5, the normal direction of the substrate passing through the optical axis passes through the intersection between the optical axis 8a of the measurement light and the substrate 4 and the rotation axis p is perpendicular to the paper surface. The rotation state of the polarization plane of the measurement light 8 transmitted through the substrate 4 was examined by tilting the upper and lower ends of the substrate 4 forward and backward in the traveling direction of the measurement light 8 so that the tip of the vector n was moved up and down. At a certain tilt angle, the polarization plane of the measurement light 8 transmitted through the substrate 4 coincides with the polarization plane of the measurement light 8 incident on the substrate 4 and no rotation occurs.
その結果として、測定光８の進行方向が一軸結晶であるSiC単結晶基板４の光学軸と一致したことにより、検出器７で検出される光量がゼロとなった。この状態での基板４の法線ｎと測定光８の光軸とのなす角を測定したところ４．１°であり、基板４を傾斜させた向きから、このSiC単結晶基板４の結晶主軸は、測定光が基板に入射する方向（すなわち光軸）に沿って、つまり光源からの位置から基板平面を見た際にオリフラ位置が左に90°となる配置において、基板の法線方向ｎからオリフラとほぼ平行の［１１−２０］方向に、上方へ４．１°傾いていることが分った。これにより、光源から見てオリフラが左に見える面が「シリコン面」であることが確認できた。
この実施例１におけるSiC単結晶基板４の面方位測定結果を表１にまとめて示す。
As a result, the amount of light detected by the detector 7 becomes zero because the traveling direction of the measuring light 8 coincides with the optical axis of the SiC single crystal substrate 4 which is a uniaxial crystal. In this state, the angle formed between the normal n of the substrate 4 and the optical axis of the measuring light 8 was measured to be 4.1 °. From the direction in which the substrate 4 was inclined, the crystal principal axis of the SiC single crystal substrate 4 Is the normal direction n of the substrate along the direction in which the measurement light is incident on the substrate (that is, the optical axis), that is, when the orientation flat position is 90 ° to the left when the substrate plane is viewed from the position from the light source. It was found that the tilt angle was 4.1 ° upward in the [11-20] direction substantially parallel to the orientation flat. As a result, it was confirmed that the surface where the orientation flat was seen to the left when viewed from the light source was the “silicon surface”.
Table 1 summarizes the results of measurement of the plane orientation of the SiC single crystal substrate 4 in Example 1.
［比較例１］
実施例１と同じSiC単結晶基板を、従来法であるＸ線回折法により面方位を測定した。この比較例１で用いたＸ線回折装置を図６に示す。Ｘ線源１０はＭｏターゲットを有する管球線源であり、Ｘ線として、Ｍｏ Ｋα1特性Ｘ線を用いた。線源から発せられたＸ線は、線源から十分離れたところに設置したスリット１１で平行光に近い成分のみを取り出し、SiC単結晶基板４に入射した。基板４に入射したＸ線１３は、格子面でブラッグ反射され、回折Ｘ線１４がＸ線検出器１２で検出される。ブラッグ反射は任意の入射角度では起こらないため、基板４の向きを変えながら、ブラッグ反射の起こる位置を探したところ、表２に示したような結晶方位が測定された。その結果、本発明に係る実施例１の光学的な測定方法とほぼ同じ測定結果が得られることが確認された。
[Comparative Example 1]
The plane orientation of the same SiC single crystal substrate as in Example 1 was measured by the conventional X-ray diffraction method. The X-ray diffractometer used in Comparative Example 1 is shown in FIG. The X-ray source 10 is a tube source having a Mo target, and Mo Kα1 characteristic X-ray was used as the X-ray. From the X-rays emitted from the radiation source, only a component close to parallel light was extracted by the slit 11 placed sufficiently away from the radiation source, and was incident on the SiC single crystal substrate 4. The X-ray 13 incident on the substrate 4 is Bragg-reflected on the grating surface, and the diffracted X-ray 14 is detected by the X-ray detector 12. Since the Bragg reflection does not occur at an arbitrary incident angle, the position where the Bragg reflection occurs was searched for while changing the direction of the substrate 4, and the crystal orientation as shown in Table 2 was measured. As a result, it was confirmed that almost the same measurement result as that of the optical measurement method of Example 1 according to the present invention was obtained.
１ ：光源
２ ：分光器
３ ：偏光子
４ ：単結晶基板、4a：オリフラ
５ ：試料ステージ
６ ：検光子
７ ：光検出器
８ ：測定光、8a：光軸、8b：偏波面
９ ：屈折率の方位依存性による楕円、9a：短軸方向、9b：長軸方向
１０：Ｘ線源
１１：スリット
１２：Ｘ線検出器
１３：入射Ｘ線
１４：回折Ｘ線
1: Light source 2: Spectrometer 3: Polarizer 4: Single crystal substrate, 4a: Orientation flat 5: Sample stage 6: Analyzer 7: Photodetector 8: Measurement light, 8a: Optical axis, 8b: Polarization plane 9: Refraction Ellipse due to azimuth dependence of rate, 9a: minor axis direction, 9b: major axis direction 10: X-ray source 11: slit 12: X-ray detector 13: incident X-ray 14: diffracted X-ray
Claims (3)
ｉ）偏光子から取り出された直線偏光を測定光とし、該測定光が、検光子を介して、光検出器で検出される光量がゼロになるようにした状態で、
偏光子と検光子との間に測定対象の基板を配置すると共に、該基板の法線方向に沿って測定光が入射されるようにして、
光検出器側で検出される光量がゼロになるように、測定光の光軸を中心に基板を回転させて、オリフラが示す結晶方位と測定光の偏波面とのなす角を測定して、結晶主軸の傾斜方向を求め、
ii）次いで、基板を測定光の光路から外して、測定光の光軸を中心に偏光子と検光子とをそれぞれ同方向に０°超９０°未満の範囲内の角度で回転させた上で、再度光検出器側で検出される光量がゼロになるように調整して、ｉ）の測定後の回転角度を維持したまま基板を測定光の光路に再配置し、測定光の進行方向に対して該基板を前後に傾けて、基板からの出射光の偏波面が基板に入射される前の測定光の偏波面と揃う位置で、基板の法線と測定光の光軸とのなす角を測定して、結晶主軸の傾斜角度を求める、
ことを特徴とする一軸結晶からなる単結晶基板の面方位測定方法。 A method for measuring the plane orientation of a single crystal substrate comprising a uniaxial crystal and having an orientation flat,
i) With the linearly polarized light extracted from the polarizer as the measurement light, the measurement light is in a state where the amount of light detected by the photodetector through the analyzer is zero,
While arranging the substrate to be measured between the polarizer and the analyzer, the measurement light is incident along the normal direction of the substrate,
Rotate the substrate around the optical axis of the measurement light so that the amount of light detected on the photodetector side is zero, measure the angle between the crystal orientation shown by the orientation flat and the polarization plane of the measurement light, Find the tilt direction of the crystal main axis,
ii) Next, after removing the substrate from the optical path of the measurement light and rotating the polarizer and the analyzer around the optical axis of the measurement light in the same direction at an angle in the range of more than 0 ° and less than 90 °, respectively. Adjust again so that the amount of light detected on the photodetector side becomes zero, and re-arrange the substrate in the optical path of the measurement light while maintaining the rotation angle after the measurement in i), in the traveling direction of the measurement light The angle formed between the normal of the substrate and the optical axis of the measurement light at a position where the polarization plane of the light emitted from the substrate is aligned with the polarization plane of the measurement light before being incident on the substrate by tilting the substrate back and forth To determine the tilt angle of the crystal main axis,
A method of measuring a plane orientation of a single crystal substrate made of a uniaxial crystal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2013069985A JP6127649B2 (en) | 2013-03-28 | 2013-03-28 | Method for measuring plane orientation of single crystal substrate made of uniaxial crystal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2013069985A JP6127649B2 (en) | 2013-03-28 | 2013-03-28 | Method for measuring plane orientation of single crystal substrate made of uniaxial crystal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2014194352A JP2014194352A (en) | 2014-10-09 |
| JP6127649B2 true JP6127649B2 (en) | 2017-05-17 |
Family
ID=51839697
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2013069985A Active JP6127649B2 (en) | 2013-03-28 | 2013-03-28 | Method for measuring plane orientation of single crystal substrate made of uniaxial crystal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP6127649B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6444207B2 (en) * | 2015-02-17 | 2018-12-26 | 株式会社ディスコ | Inspection method and inspection apparatus for hexagonal single crystal substrate |
| KR102659810B1 (en) * | 2015-09-11 | 2024-04-23 | 삼성디스플레이 주식회사 | Crystallization measure apparatus and method of the same measure |
| JP6690983B2 (en) * | 2016-04-11 | 2020-04-28 | 株式会社ディスコ | Wafer generation method and actual second orientation flat detection method |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2698935B2 (en) * | 1990-06-04 | 1998-01-19 | 株式会社オーク製作所 | High sensitivity automatic birefringence measurement device |
| JPH05158084A (en) * | 1991-02-05 | 1993-06-25 | Seizo Miyata | Measuring instrument for linear and nonlinear optical sensing rate |
| JPH05340878A (en) * | 1992-06-05 | 1993-12-24 | Nec Corp | Method and device for determining crystal orientation |
-
2013
- 2013-03-28 JP JP2013069985A patent/JP6127649B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2014194352A (en) | 2014-10-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6127649B2 (en) | Method for measuring plane orientation of single crystal substrate made of uniaxial crystal | |
| Ponce et al. | Direct imaging of impurity‐induced Raman scattering in GaN | |
| KR102425117B1 (en) | Inspection method and inspection apparatus of hexagonal single crystal substrate | |
| US20090236542A1 (en) | Optical inspection | |
| JP2010520146A (en) | diamond | |
| Darakchieva et al. | Strain-related structural and vibrational properties of thin epitaxial AlN layers | |
| US20230078982A1 (en) | Chamfered silicon carbide substrate and method of chamfering | |
| US10350788B2 (en) | Method for slicing workpiece and workpiece holder | |
| US20230093945A1 (en) | Method and apparatus for producing at least one modification in a solid body | |
| JP2007121324A (en) | X-ray diffractometer | |
| US2326319A (en) | Crystal working apparatus | |
| US10697088B2 (en) | Single-crystal diamond material, and tool, radiation temperature monitor, and infrared optical component including said diamond material | |
| Capelle et al. | Polarimetric analysis of stress anisotropy in nanomechanical silicon nitride resonators | |
| JP2020107745A (en) | Method of evaluating semiconductor wafer and method of manufacturing semiconductor wafer | |
| JP6795521B2 (en) | Single crystal diamond, method for producing single crystal diamond and chemical vapor deposition equipment used for it | |
| JP2013258243A (en) | Manufacturing method and manufacturing device of compound semiconductor substrate | |
| US20070201023A1 (en) | Method for determining crystalline orientation using raman spectroscopy | |
| US4862488A (en) | Device for measuring the orientation of bulk monocrystalline materials using the Laue method | |
| JP2006016230A (en) | Quartz crystal thin film | |
| Van Enckevort et al. | Stress birefringence microscopy of dislocations in type-Ia natural diamond | |
| JP3918216B2 (en) | Single crystal cutting apparatus and method | |
| JP2006258594A (en) | Automatic double refraction measuring instrument and double refraction measuring method using it | |
| CA1040748A (en) | Apparatus and method for orienting monocrystalline material for sawing | |
| US5550374A (en) | Methods and apparatus for determining interstitial oxygen content of relatively large diameter silicon crystals by infrared spectroscopy | |
| JP2006071354A (en) | Crystallinity evaluation method of crystal surface layer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20151106 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20160824 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20160906 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20161003 |
|
| 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: 20170314 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20170327 |
|
| R151 | Written notification of patent or utility model registration |
Ref document number: 6127649 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R151 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313113 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313111 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |