JP2015200610A - Defect measurement device and defect measurement method - Google Patents

Defect measurement device and defect measurement method Download PDF

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JP2015200610A
JP2015200610A JP2014080715A JP2014080715A JP2015200610A JP 2015200610 A JP2015200610 A JP 2015200610A JP 2014080715 A JP2014080715 A JP 2014080715A JP 2014080715 A JP2014080715 A JP 2014080715A JP 2015200610 A JP2015200610 A JP 2015200610A
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守矢　一男
Kazuo Moriya
一男 守矢
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Raytex Corp
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Abstract

PROBLEM TO BE SOLVED: To provide one of a defect measurement device and defect measurement method that can highly accurately measure defects.SOLUTION: A defect measurement device 100 irradiating a sample 1 with laser light stopped down by a condenser lens 3a, photographing scattered light from the sample 1 via an observation lens 4a and detecting a defect of an interior of the sample 1, in which the sample 1 and the observation lens 4a are immersed by a liquid L, and the liquid L fills between sample 1 and the observation lens 4a.

Description

本発明は、液浸のレンズを介して、ビーム径を絞ったレーザ光を試料に照射し、当該試料からの散乱光を、液浸のレンズを介して撮像し、当該撮像結果に基づいて当該試料の内部の欠陥を測定する欠陥測定装置及び欠陥測定方法に関するものである。   The present invention irradiates a sample with a laser beam with a reduced beam diameter through an immersion lens, images scattered light from the sample through the immersion lens, and based on the imaging result, The present invention relates to a defect measuring apparatus and a defect measuring method for measuring defects inside a sample.

従来、レーザ光を試料に照射し、当該試料からの散乱光を撮像し、撮像した画像に対して所定の画像処理を施し、この画像処理結果に基づいて試料の内部の欠陥の密度分布などを測定する欠陥測定装置及び欠陥測定方法が知られている（例えば、特許文献１参照）。
この欠陥測定装置及び欠陥測定方法は、９０度散乱法を用いるもので、試料の内部の欠陥によって散乱した散乱光を撮像することによって欠陥粒子などの二次元配置を反映した二次元画像を得るようになっている。 Conventionally, a sample is irradiated with laser light, the scattered light from the sample is imaged, predetermined image processing is performed on the captured image, and the density distribution of defects inside the sample is determined based on the image processing result. A defect measuring apparatus and a defect measuring method for measuring are known (for example, see Patent Document 1).
This defect measuring apparatus and defect measuring method uses a 90-degree scattering method, and obtains a two-dimensional image reflecting a two-dimensional arrangement of defective particles by imaging scattered light scattered by defects inside the sample. It has become.

特許第２６０４６０７号公報Japanese Patent No. 2604607

ところで、半導体製造等の分野においては、従来の検出感度が概ね１７ｎｍφであるのに対して、昨今のデバイスルールでは１０ｎｍφ台の検出感度が要求されている。これを、単純に散乱強度が欠陥サイズの６乗に比例するとして計算すれば、昨今の欠陥測定装置及び欠陥測定方法では従来の欠陥測定装置及び欠陥測定方法の約２４倍の検出感度が要求されることとなる。
この検出感度を達成するためには、試料の表面の傷などからの迷光除去、試料内部のＰＬ（蛍光）による背景輝度の低減、高屈折率の試料の場合の実効ＮＡ（Numerical aperture）の向上、高屈折率の試料の場合の表面での反射率の低減などの対策が考えられる。 By the way, in the field of semiconductor manufacturing and the like, the conventional detection sensitivity is approximately 17 nmφ, whereas the recent device rule requires a detection sensitivity of the order of 10 nmφ. If this is calculated simply by assuming that the scattering intensity is proportional to the sixth power of the defect size, the recent defect measuring apparatus and defect measuring method require a detection sensitivity of about 24 times that of the conventional defect measuring apparatus and defect measuring method. The Rukoto.
In order to achieve this detection sensitivity, removal of stray light from scratches on the surface of the sample, reduction of background luminance due to PL (fluorescence) inside the sample, improvement of effective NA (Numerical aperture) in the case of a sample with a high refractive index Measures such as reduction of the reflectance on the surface in the case of a high refractive index sample can be considered.

本発明は、かかる点に鑑みてなされたものであって、高感度で試料の内部の欠陥の測定が可能な欠陥測定装置及び欠陥測定方法を提供することを目的とする。   The present invention has been made in view of this point, and an object of the present invention is to provide a defect measuring apparatus and a defect measuring method capable of measuring defects inside a sample with high sensitivity.

第１の手段は、
集光用レンズでビーム径を絞ったレーザ光を試料に照射し、当該試料の内部の欠陥によって散乱した散乱光を観察用レンズを介して撮像し当該撮像結果に基づいて当該試料の内部の欠陥を測定する欠陥測定装置において、
前記試料及び前記観察用レンズを液体で浸漬して、前記試料と前記観察用レンズとの間を前記液体で満たしたことを特徴とする。 The first means is
The sample is irradiated with laser light whose beam diameter is reduced by the condensing lens, and the scattered light scattered by the defect inside the sample is imaged through the observation lens, and the defect inside the sample based on the imaging result In a defect measuring device for measuring
The sample and the observation lens are immersed in a liquid, and the space between the sample and the observation lens is filled with the liquid.

第２の手段は、第１の手段において、前記集光用レンズを前記液体で浸漬して、前記集光用レンズと前記試料との間を前記液体で満たしたことを特徴とする。   The second means is characterized in that, in the first means, the condensing lens is immersed in the liquid, and the space between the condensing lens and the sample is filled with the liquid.

第３の手段は、第１の手段又は第２の手段において、前記レーザ光は前記試料の第１の面に照射され、前記第１の面と交差する第２の面からの前記散乱光を前記観察用レンズを介して撮像することを特徴とする。   A third means is the first means or the second means, wherein the laser light is irradiated onto the first surface of the sample, and the scattered light from the second surface intersecting the first surface is emitted. The imaging is performed through the observation lens.

第４の手段は、第１の手段又は第２の手段において、前記レーザ光は前記試料の第１の面に照射され、前記第１の面から出る前記散乱光を前記観察用レンズを介して撮像することを特徴とする。   According to a fourth means, in the first means or the second means, the laser light is applied to the first surface of the sample, and the scattered light emitted from the first surface is transmitted through the observation lens. It is characterized by imaging.

第５の手段は、第１の手段から第４の手段のいずれか一の手段において、前記液体は油であることを特徴とする。   According to a fifth means, in any one of the first to fourth means, the liquid is oil.

第６の手段は、
集光用レンズでビーム径を絞ったレーザ光を試料に照射し、当該試料の内部の欠陥によって散乱した散乱光を観察用レンズを介して撮像し当該撮像結果に基づいて当該試料の内部の欠陥を測定するにあたり、
前記集光用レンズを介して前記レーザ光を前記試料に照射し、前記試料との間を液体で満たした前記観察用レンズを介して前記散乱光を撮像することを特徴とする。 The sixth means is
The sample is irradiated with laser light whose beam diameter is reduced by the condensing lens, and the scattered light scattered by the defect inside the sample is imaged through the observation lens, and the defect inside the sample based on the imaging result In measuring
The sample is irradiated with the laser light through the condensing lens, and the scattered light is imaged through the observation lens filled with a liquid between the sample and the sample.

本発明に係る欠陥測定装置及び欠陥測定方法によれば、少なくとも試料及び観察用レンズが液体で浸漬されて、試料と観察用レンズとの間が液体で満たされているので、観察用レンズの開口数ＮＡが向上する。その結果、欠陥像の分解能が向上し、高感度で欠陥測定ができることになる。また、受光量及び欠陥輝度を高めることができる。
また、レーザ光を集光用レンズによって絞っているので迷光の発生を抑制することができる。
さらに、試料が液体で浸漬されているので、高屈折率の試料の場合の表面での反射率を低減することができ、試料の表面での乱反射を低減し、背景輝度の低減を図ることができる。 According to the defect measuring apparatus and the defect measuring method according to the present invention, at least the sample and the observation lens are immersed in the liquid, and the space between the sample and the observation lens is filled with the liquid. The number NA is improved. As a result, the resolution of the defect image is improved, and the defect measurement can be performed with high sensitivity. In addition, the amount of received light and the defect luminance can be increased.
Further, since the laser light is focused by the condensing lens, generation of stray light can be suppressed.
Furthermore, since the sample is immersed in a liquid, the reflectance on the surface in the case of a sample with a high refractive index can be reduced, the diffuse reflection on the surface of the sample can be reduced, and the background luminance can be reduced. it can.

本発明の第１の実施形態である欠陥測定装置の構成を示すブロック図である。It is a block diagram which shows the structure of the defect measuring device which is the 1st Embodiment of this invention. ９０度散乱法の原理を説明する概略図である。It is the schematic explaining the principle of a 90 degree | times scattering method. 本発明の第１の実施形態である欠陥測定装置の要部を示す概略図である。It is the schematic which shows the principal part of the defect measuring device which is the 1st Embodiment of this invention. 比較例の非液浸光学系を示す概略図である。It is the schematic which shows the non-immersion optical system of a comparative example. 本発明の第２の実施形態である欠陥測定装置の要部を示す概略図である。It is the schematic which shows the principal part of the defect measuring apparatus which is the 2nd Embodiment of this invention. 本発明の第３の実施形態である欠陥測定装置の要部を示す概略図である。It is the schematic which shows the principal part of the defect measuring apparatus which is the 3rd Embodiment of this invention.

以下、この発明を実施するための形態である欠陥測定装置及び欠陥測定方法について説明する。   Hereinafter, a defect measuring apparatus and a defect measuring method which are forms for carrying out the present invention will be described.

［第１の実施形態］
１.欠陥測定装置の概略構成について
図１は、本発明の実施形態である欠陥測定装置の構成を示すブロック図である。
同図において、符号１は測定対象である試料（被検物体）を指示している。
この欠陥測定装置１００は、試料１に照射すべきレーザ光を発生するレーザ発生部２と、レーザ発生部２で発生したレーザ光を試料１に照射する照射用光学系３と、試料１の内部の欠陥によって散乱された散乱光を観察するための観察用光学系４と、観察用光学系４を経た光を撮像する撮像部５と、撮像結果に基づいて試料１内の欠陥を測定する欠陥測定部として機能する制御部６とを備えている。
また、この欠陥測定装置１００は、試料１を載せるためのＸＹＺステージ７と、駆動部８ａ，８ｂ，８ｃと、欠陥の測定のための各種プログラム及びデータを記憶する記憶部９と、欠陥の測定のために必要な各種画像等を表示するための表示部１０と、各種指令を入力するための入力部１１とを備えている。 [First Embodiment]
1. Schematic Configuration of Defect Measuring Device FIG. 1 is a block diagram showing a configuration of a defect measuring device that is an embodiment of the present invention.
In the figure, reference numeral 1 indicates a sample (object to be measured) that is a measurement target.
The defect measuring apparatus 100 includes a laser generating unit 2 that generates laser light to be irradiated on the sample 1, an irradiation optical system 3 that irradiates the sample 1 with laser light generated by the laser generating unit 2, and the interior of the sample 1. An observation optical system 4 for observing the scattered light scattered by the defect, an imaging unit 5 for imaging light that has passed through the observation optical system 4, and a defect for measuring a defect in the sample 1 based on the imaging result And a control unit 6 functioning as a measurement unit.
Further, the defect measuring apparatus 100 includes an XYZ stage 7 on which the sample 1 is placed, driving units 8a, 8b, and 8c, a storage unit 9 that stores various programs and data for measuring defects, and a defect measurement. Display unit 10 for displaying various images necessary for the purpose and an input unit 11 for inputting various commands.

制御部６は、ＣＰＵ等によって構成され、記憶部９に記憶された各種プログラムやデータに従って、各種画像処理を行ったり、欠陥測定装置１００の各部を統括制御したりする。後者の統括制御としては、制御部６は、駆動部８ａ，８ｂ，８ｃ，８ｄ、記憶部９、表示部１０及び入力部１１を制御する。
そして、駆動部８ａは、制御部６の制御下で、ＸＹＺステージ７を駆動する。また、駆動部８ｂは、制御部６の制御下で、レーザ発生部２を駆動する。さらに、駆動部８ｃは、制御部６の制御下で、観察用光学系４を駆動するとともに、撮像部５を駆動する。 The control unit 6 is configured by a CPU or the like, and performs various types of image processing according to various programs and data stored in the storage unit 9 and performs overall control of each unit of the defect measurement apparatus 100. As the latter overall control, the control unit 6 controls the drive units 8a, 8b, 8c, 8d, the storage unit 9, the display unit 10, and the input unit 11.
Then, the drive unit 8 a drives the XYZ stage 7 under the control of the control unit 6. In addition, the drive unit 8 b drives the laser generation unit 2 under the control of the control unit 6. Further, the drive unit 8 c drives the observation optical system 4 and drives the imaging unit 5 under the control of the control unit 6.

２.９０度散乱法の原理について
次に、この欠陥測定装置１００によって実行される９０度散乱法の原理を説明する。
この９０度散乱法においては、図２に示すように、試料１の第１の面Ｆ１にはビーム径が絞られたレーザ光が照射され、試料１内の欠陥によって散乱され試料１の第２の面Ｆ２から出た散乱光が結像される。例えば、シリコンウェーハでは、第１の面Ｆ１としてはウェーハ面である（１００）面、第２の面Ｆ２としては劈開面である（１１０）面が選択される。
この９０度散乱法においては、まず、試料１を図２の−Ｘ方向に移動させ、試料１に対してレーザ光を１ライン分スキャンさせる。図２にはレーザ光のスキャン方向が矢印Ａで示されている。そして、レーザ光の１ライン分スキャンさせている間、試料１内の欠陥によって散乱された散乱光が結像される。図２には撮像部受光面で結像された欠陥画像が示されている。
その後、レーザ光の１ライン分のスキャンが終わると、試料１を図２のZ方向に移動させ、次のラインでレーザ光を１ライン分スキャンさせる。このときも、試料１内の欠陥によって散乱された散乱光が結像される。
以上のようにして、試料１内の欠陥に対応した二次元欠陥画像が得られる。そして、この二次元欠陥画像に基づいて欠陥の測定が行われる。これが９０度散乱法の原理である。 2. Principle of 90 degree scattering method Next, the principle of the 90 degree scattering method executed by the defect measuring apparatus 100 will be described.
In the 90-degree scattering method, as shown in FIG. 2, the first surface F1 of the sample 1 is irradiated with laser light with a narrowed beam diameter, and is scattered by defects in the sample 1, and the second surface of the sample 1 is scattered. The scattered light from the surface F2 is imaged. For example, in a silicon wafer, the (100) plane which is a wafer plane is selected as the first plane F1, and the (110) plane which is a cleavage plane is selected as the second plane F2.
In the 90-degree scattering method, first, the sample 1 is moved in the −X direction in FIG. 2 and the sample 1 is scanned with one line of laser light. In FIG. 2, the scanning direction of the laser light is indicated by an arrow A. While the laser beam is scanned for one line, the scattered light scattered by the defect in the sample 1 is imaged. FIG. 2 shows a defect image formed on the light receiving surface of the imaging unit.
Thereafter, when the scanning of one line of laser light is completed, the sample 1 is moved in the Z direction in FIG. 2, and the laser light is scanned by one line on the next line. Also at this time, the scattered light scattered by the defects in the sample 1 is imaged.
As described above, a two-dimensional defect image corresponding to the defect in the sample 1 is obtained. Then, the defect is measured based on the two-dimensional defect image. This is the principle of the 90 degree scattering method.

３.第１の実施形態である欠陥測定装置の要部について
続いて、欠陥測定装置１００の要部について説明する。
図３は、この欠陥測定装置１００の要部の概略を示している。
この欠陥測定装置１００においては、試料１と、照射用光学系３のうち試料１に対向する集光用レンズ３ａと、観察用光学系４のうち試料１に対向する観察用レンズ（対物レンズ）４ａとが液体Ｌによって浸漬されている。すなわち、集光用レンズ３ａと試料１との間、及び、試料１と観察用レンズ４ａとの間が液体Ｌで満たされている。このような構成を実現するため、図１に示すように、ＸＹＺステージ７上に液体Ｌを入れた浴槽１２を設置し、この液体Ｌ内に試料1、集光用レンズ３ａ及び観察用レンズ４ａを浸漬させている。
この場合、使用される液体としては水や油が挙げられ、好適には、試料１の屈折率により近い屈折率の高い油が使用される。例えば、試料１がシリコンの場合に使用される液体の具体的を挙げれば、純水（屈折率１．３３）、イマージョンオイル（屈折率１．５１）やアニソール（屈折率１．５１）等が挙げられる。勿論、液体はこれらに限定されるものではない。
また、この欠陥測定装置１００においては、レーザ光を試料１に対してスキャンさせなければならないことから、試料１と光学系とを相対移動させる必要がある。そこで、第１の実施形態の欠陥測定装置１００では、試料１を液体Ｌが満たされた浴槽１２内に基台１３を介して固定し、光学系である照射用光学系３及び観察用光学系４の一部を浴槽１２の上方から浴槽１２内の液体Ｌに浸漬し、ＸＹＺステージ７にて試料１を移動させることにより、試料１に対して照射用光学系３及び観察用光学系４を相対移動できる構造としている。試料１と光学系とを相対移動させることが可能な構造であるならば、この構造に限定されないことは言うまでもない。 3. About the principal part of the defect measuring apparatus which is 1st Embodiment Then, the principal part of the defect measuring apparatus 100 is demonstrated.
FIG. 3 shows an outline of a main part of the defect measuring apparatus 100.
In this defect measuring apparatus 100, the sample 1, the condensing lens 3a that faces the sample 1 in the irradiation optical system 3, and the observation lens (objective lens) that faces the sample 1 in the observation optical system 4 4a is immersed in the liquid L. That is, the liquid L is filled between the condensing lens 3a and the sample 1 and between the sample 1 and the observation lens 4a. In order to realize such a configuration, as shown in FIG. 1, a bath 12 containing a liquid L is placed on the XYZ stage 7, and the sample 1, the condensing lens 3a and the observation lens 4a are placed in the liquid L. Is immersed.
In this case, examples of the liquid to be used include water and oil. Preferably, an oil having a high refractive index closer to the refractive index of the sample 1 is used. For example, specific examples of liquids used when the sample 1 is silicon include pure water (refractive index 1.33), immersion oil (refractive index 1.51), anisole (refractive index 1.51), and the like. Can be mentioned. Of course, the liquid is not limited to these.
Further, in the defect measuring apparatus 100, since the laser beam must be scanned with respect to the sample 1, it is necessary to relatively move the sample 1 and the optical system. Therefore, in the defect measuring apparatus 100 of the first embodiment, the sample 1 is fixed in the bathtub 12 filled with the liquid L via the base 13, and the irradiation optical system 3 and the observation optical system which are optical systems are used. 4 is immersed in the liquid L in the bathtub 12 from above the bathtub 12, and the sample 1 is moved on the XYZ stage 7, whereby the irradiation optical system 3 and the observation optical system 4 are moved with respect to the sample 1. It has a structure that allows relative movement. Needless to say, the structure is not limited to this structure as long as the structure can relatively move the sample 1 and the optical system.

４.第１の実施形態に係る欠陥測定方法について
この欠陥測定装置１００、及び、この欠陥測定装置１００によって実行される欠陥測定方法によれば、次のようにして欠陥の測定が行われる。
すなわち、レーザ発生部２で発生されたレーザ光は照射用光学系３に入り、照射用光学系３の集光用レンズ３ａによってビーム径が絞られる。ここで、「絞る」とは、光量はそのままにビーム径を細くすることを言う。そして、集光用レンズ３ａによってビーム径が絞られたレーザ光は図３に示すように液体Ｌ中を通り試料１の第１の面Ｆ１に照射される。この第１の面Ｆ１に照射されたレーザ光はその一部が第１の面Ｆ１で反射されるが、大部分が試料１の内部に導かれ、内部の欠陥で散乱される。そして、散乱によって生じた散乱光で第２の面Ｆ２から出た散乱光は液体Ｌ中を経て観察用レンズ４ａで集められ、観察用光学系４の他の光学素子を経て撮像部５に到達し結像される。そして、この撮像部５で光電変換が行われ、この光電変換により撮像部５で生成された電気信号は制御部６（図１参照）に送られる。制御部６は、記憶部９に記憶された欠陥測定用プログラムやデータに従って、この電気信号を処理し、欠陥の測定を行う。 4. About Defect Measurement Method According to First Embodiment According to this defect measurement device 100 and the defect measurement method executed by this defect measurement device 100, the defect is measured as follows.
That is, the laser light generated by the laser generator 2 enters the irradiation optical system 3, and the beam diameter is reduced by the condensing lens 3 a of the irradiation optical system 3. Here, “to squeeze” means to reduce the beam diameter while keeping the light amount as it is. Then, the laser beam whose beam diameter is narrowed by the condensing lens 3a passes through the liquid L and is irradiated onto the first surface F1 of the sample 1 as shown in FIG. A part of the laser light irradiated to the first surface F1 is reflected by the first surface F1, but most of the laser light is guided into the sample 1 and scattered by internal defects. Then, the scattered light generated by the scattering and emitted from the second surface F2 passes through the liquid L and is collected by the observation lens 4a, and reaches the imaging unit 5 through the other optical elements of the observation optical system 4. And imaged. Then, photoelectric conversion is performed by the imaging unit 5, and an electrical signal generated by the imaging unit 5 by the photoelectric conversion is sent to the control unit 6 (see FIG. 1). The control unit 6 processes the electrical signal according to the defect measurement program and data stored in the storage unit 9 and measures the defect.

５.第１の実施形態である欠陥測定装置及び欠陥測定方法の効果について
以上のように構成された欠陥測定装置１００、及び、この欠陥測定装置１００によって実行される欠陥測定方法の代表的な効果を挙げれば次の通りである。
すなわち、集光用レンズ３ａを出たレーザ光は液体Ｌ中を経て試料１の第１の面Ｆ１に導かれるので、レーザ光が空気中を経て試料１の第１の面Ｆ１に導かれる場合と比べて、第１の面Ｆ１での反射が少なくなり、試料１内に導かれる光量が増大することになる。
さらに、試料１と観察用レンズ４ａとの間が液体Ｌで満たされているため、観察用レンズ４ａの開口数ＮＡが向上する。具体的には観察用レンズは通常×５０でＮＡ０．５程度であるが、液浸にした場合にはＮＡ０．８〜１．０を実現できる。その結果、欠陥画像の分解能が向上し、高感度で欠陥測定ができることになる。また、観察用レンズ４ａの開口数ＮＡが向上するため、受光量及び欠陥輝度を高めることができる。このことは、逆に言えば、同じ欠陥画像の分解能を得ようとするならば、レーザ光の入射光量を低減できることを意味している。そして、入射光量を低減させることとすれば、それに起因するＰＬ光の発生を抑制することができる。
また、レーザ光を集光用レンズ３ａによって絞っているので迷光が生じにくくなる。
さらに、試料１が液体Ｌで浸漬されているため、高屈折率の試料１の場合の表面での反射率を低減することで、試料１の表面での乱反射を低減し、背景輝度の低減を図ることができる。 5. About Effect of Defect Measuring Device and Defect Measuring Method as First Embodiment Typical effect of defect measuring device 100 configured as described above and the defect measuring method executed by this defect measuring device 100 Is as follows.
That is, since the laser light exiting the condensing lens 3a is guided to the first surface F1 of the sample 1 through the liquid L, the laser light is guided to the first surface F1 of the sample 1 through the air. As a result, the reflection at the first surface F1 is reduced, and the amount of light guided into the sample 1 is increased.
Furthermore, since the space between the sample 1 and the observation lens 4a is filled with the liquid L, the numerical aperture NA of the observation lens 4a is improved. Specifically, the observation lens is usually x50 and has an NA of about 0.5, but when immersed, NA of 0.8 to 1.0 can be realized. As a result, the resolution of the defect image is improved, and the defect measurement can be performed with high sensitivity. In addition, since the numerical aperture NA of the observation lens 4a is improved, the amount of received light and the defect luminance can be increased. In other words, this means that the amount of incident laser light can be reduced if the resolution of the same defect image is to be obtained. If the amount of incident light is reduced, the generation of PL light due to it can be suppressed.
Further, since the laser light is focused by the condensing lens 3a, stray light is hardly generated.
Furthermore, since the sample 1 is immersed in the liquid L, by reducing the reflectance on the surface in the case of the sample 1 having a high refractive index, the irregular reflection on the surface of the sample 1 is reduced, and the background luminance is reduced. Can be planned.

次に、欠陥測定装置１００、及び、この欠陥測定装置１００によって実行される欠陥測定方法の効果を具体的数値に基づいて示す。その結果は、次表の通りである。
ここでは、非液浸光学系を用いた場合と、水浸光学系を用いた場合と、油浸光学系を用いた場合との効果の相違を示している。非液浸光学系と液浸光学系との効果の相違を視覚的に見やすいように、図４に比較対象の非液浸光学系を示している。
この非液浸光学系は、図３に示す液浸光学系に対応するもので、その相違は、試料1、集光用レンズ３ａ及び観察用レンズ４ａが液体に浸漬されていない点で図３に示す液浸光学系と異なっている。この非液浸光学系は、その他の点では、図３に示す液浸光学系と同じ構成となっている。
なお、水浸光学系と油浸光学系との相違は、試料1、集光用レンズ３ａ及び観察用レンズ４ａを浸漬する液体Ｌが水か油かの点である。
上の表において、ＮＡはｎ×ｓｉｎθの式から求められ、分解能は０．６１（１＋１／ｍ）λ／ＮＡの式から求められ、表面反射率は（ｎ０−ｎ１）２／（ｎ０−ｎ１）２の式から求められる。また、受光量は（ＮＡ）２に比例し、欠陥の輝度は（NA）４にそれぞれ比例する。ここで、nは試料と観察用レンズとの間の媒質の屈折率、θは光軸と観察用レンズの最も外側に入る光線とがなす角、λは波長、mは倍率である。また、ｎ０は媒質の屈折率、ｎ１は反射する面の屈折率である。さらに、受光量及び欠陥の輝度については空気中を１とした場合の相対的な値を示している。
なお、ちなみに、ＰＬ光について言えば、空気中のＰＬ光を基準とした場合に、表面反射率を３５％低減した系では入射光量を３５％減ずることができ４２．３％となり、背景輝度の大きな低減が図れた。
また、第１の実施形態である欠陥測定装置１００の欠陥密度の測定限界について説明すれば、従来法の密度限界は１Ｅ１０ｃｍ−３程度の欠陥密度が上限であったが、集光用レンズ３ａ及び観察用レンズ４ａを液浸にすることによって入射ビーム径は約半分（ＮＡ０．４から０．８）に、さらに分解能向上による密度限界向上は２．５６倍（１／分解能２）であることから、これまでの約５倍の欠陥密度を計測することが可能となった。 Next, the effects of the defect measuring apparatus 100 and the defect measuring method executed by the defect measuring apparatus 100 will be shown based on specific numerical values. The results are shown in the following table.
Here, the difference in effect between the case where the non-immersion optical system is used, the case where the water immersion optical system is used, and the case where the oil immersion optical system is used is shown. FIG. 4 shows a comparative non-immersion optical system so that the difference in effect between the non-immersion optical system and the immersion optical system can be easily seen visually.
This non-immersion optical system corresponds to the immersion optical system shown in FIG. 3. The difference is that the sample 1, the condensing lens 3a, and the observation lens 4a are not immersed in the liquid. This is different from the immersion optical system shown in FIG. This non-immersion optical system has the same configuration as the immersion optical system shown in FIG. 3 in other respects.
The difference between the water immersion optical system and the oil immersion optical system is that the liquid L in which the sample 1, the condensing lens 3a, and the observation lens 4a are immersed is water or oil.
In the above table, NA is obtained from the equation of n × sin θ, the resolution is obtained from the equation of 0.61 (1 + 1 / m) λ / NA, and the surface reflectance is (n 0 −n 1 ) 2 / (n 0 −n 1 ) 2 The amount of received light is proportional to (NA) 2 , and the brightness of the defect is proportional to (NA) 4 . Here, n is the refractive index of the medium between the sample and the observation lens, θ is the angle formed by the optical axis and the light beam entering the outermost side of the observation lens, λ is the wavelength, and m is the magnification. N 0 is the refractive index of the medium, and n 1 is the refractive index of the reflecting surface. Further, relative values for the amount of received light and the brightness of the defect are shown when air is set to 1.
Incidentally, with respect to the PL light, when the PL light in the air is used as a reference, the incident light quantity can be reduced by 35% in the system in which the surface reflectance is reduced by 35%, which is 42.3%. A great reduction was achieved.
In addition, the defect density measurement limit of the defect measurement apparatus 100 according to the first embodiment will be described. The density limit of the conventional method is the upper limit of the defect density of about 1E10 cm −3, but the condensing lens 3a and By immersing the observation lens 4a, the incident beam diameter is about half (NA 0.4 to 0.8), and the density limit improvement due to the resolution improvement is 2.56 times (1 / resolution 2 ). Thus, it has become possible to measure the defect density about five times higher than before.

［第２の実施形態］
図５は第２の実施形態の要部を示している。
この欠陥測定装置２００においては、試料１と、照射用光学系３のうち試料１に対向する集光用レンズ３ａと、観察用光学系４のうち試料１に対向する観察用レンズ４ａとが液体によって浸漬されている。そして、集光用レンズ３ａと試料１との間、及び、試料１と観察用レンズ４ａとの間が液体で満たされている。この欠陥測定装置２００は、この点では、第１の実施形態である欠陥測定装置１００と同じ構成となっている。
しかし、この欠陥測定装置２００は、試料１、照射用光学系３及び観察用光学系４が液面に対して傾斜しており、試料１の端部の一部だけが液体に浸漬されている点が第１の実施形態である欠陥測定装置１００と異なっている。
なお、この欠陥測定装置２００のその他の構成については第１の実施形態である欠陥測定装置１００と同様なので、図示及び説明は省略する。この欠陥測定装置２００において、第１の実施形態である欠陥測定装置１００の構成要素に相当する部分については、同じ符号を付してある。 [Second Embodiment]
FIG. 5 shows the main part of the second embodiment.
In this defect measuring apparatus 200, the sample 1, the condensing lens 3 a that faces the sample 1 in the irradiation optical system 3, and the observation lens 4 a that faces the sample 1 in the observation optical system 4 are liquid. Soaked by. The space between the condensing lens 3a and the sample 1 and the space between the sample 1 and the observation lens 4a are filled with liquid. In this respect, the defect measuring apparatus 200 has the same configuration as the defect measuring apparatus 100 according to the first embodiment.
However, in the defect measuring apparatus 200, the sample 1, the irradiation optical system 3, and the observation optical system 4 are inclined with respect to the liquid surface, and only a part of the end of the sample 1 is immersed in the liquid. The point is different from the defect measuring apparatus 100 according to the first embodiment.
Since the other configuration of the defect measuring apparatus 200 is the same as that of the defect measuring apparatus 100 according to the first embodiment, illustration and description thereof are omitted. In this defect measuring apparatus 200, portions corresponding to components of the defect measuring apparatus 100 according to the first embodiment are denoted by the same reference numerals.

この第２の実施形態である欠陥測定装置２００、及び、この欠陥測定装置２００によって実行される欠陥測定方法によれば、第１の実施形態である欠陥測定装置１００、及び、この欠陥測定装置１００によって実行される結晶欠陥測定方法と同様の効果が得られる。
なお、この第２の実施形態である欠陥測定装置２００、及び、この結晶欠陥測定装置２００によって実行される欠陥測定方法は、特に、大型の試料、例えば大型のウェーハの欠陥測定装置及び欠陥測定方法に適している。大型化したウェーハ全体を液体に浸漬する構成とすれば、装置全体が大型化するが、ウェーハの端部だけ液体に浸漬することとすれば、装置の大型化を抑制することができる。 According to the defect measuring apparatus 200 according to the second embodiment and the defect measuring method executed by the defect measuring apparatus 200, the defect measuring apparatus 100 according to the first embodiment and the defect measuring apparatus 100 The same effect as that of the crystal defect measurement method executed by the method can be obtained.
The defect measuring apparatus 200 according to the second embodiment and the defect measuring method executed by the crystal defect measuring apparatus 200 are particularly suitable for a large sample, for example, a large wafer defect measuring apparatus and defect measuring method. Suitable for If the entire wafer that has been increased in size is immersed in the liquid, the entire apparatus is increased in size, but if only the edge of the wafer is immersed in the liquid, the increase in the size of the apparatus can be suppressed.

［第３の実施形態］
図６は第３の実施形態の要部を示している。
この欠陥測定装置３００においては、試料１と、照射用光学系３のうち試料１に対向する集光用レンズ３ａと、観察用光学系４のうち試料１に対向する観察用レンズ４ａとが液体によって浸漬されている。そして、集光用レンズ３ａと試料１との間、及び、試料１と観察用レンズ４ａとの間が液体で満たされている。この欠陥測定装置３００は、この点では、第１の実施形態である欠陥測定装置１００と同じ構成となっている。
しかし、この欠陥測定装置３００は、９０度散乱法を用いない点で第１の欠陥測定装置１００とは異なっている。 [Third Embodiment]
FIG. 6 shows the main part of the third embodiment.
In this defect measuring apparatus 300, the sample 1, the condensing lens 3a facing the sample 1 in the irradiation optical system 3, and the observation lens 4a facing the sample 1 in the observation optical system 4 are liquid. Soaked by. The space between the condensing lens 3a and the sample 1 and the space between the sample 1 and the observation lens 4a are filled with liquid. This defect measuring apparatus 300 has the same configuration as the defect measuring apparatus 100 according to the first embodiment in this respect.
However, this defect measuring apparatus 300 is different from the first defect measuring apparatus 100 in that the 90-degree scattering method is not used.

この欠陥測定装置３００は、液浸の斜入射観察法を用いている。
具体的には、この欠陥測定装置３００は、試料１の表面の斜め上方からレーザ光を試料１に照射し、試料１の表面に垂直な方向に配された観察用光学系４を介して欠陥像を結像させる構成となっている。なお、ここでは試料１の表面に垂直な方向に配された観察用光学系４を用いているが、観察用光学系４も試料１の法線方向に対して傾斜して配置されていてもよい。 The defect measuring apparatus 300 uses an immersion oblique incidence observation method.
Specifically, the defect measuring apparatus 300 irradiates the sample 1 with laser light obliquely from above the surface of the sample 1 and passes the defect through the observation optical system 4 arranged in a direction perpendicular to the surface of the sample 1. An image is formed. Although the observation optical system 4 arranged in the direction perpendicular to the surface of the sample 1 is used here, the observation optical system 4 may also be arranged inclined with respect to the normal direction of the sample 1. Good.

そして、この場合にも、集光用レンズ３ａ及び観察用レンズ４ａを液体に浸漬させている。
なお、この場合、集光用レンズ３ａを液浸とすることで、試料１を移動したことに伴って生じる波面揺れの影響をなくすことができる。
また、表面散乱（Haze）の影響を低減させることができる。すなわち、表面散乱は表面反射と関係することから、液浸の斜入射観察系として構成すれば、３５〜５０％程度、表面散乱の影響を低減させることができる。表面散乱は内部欠陥の観察にとって大きな阻害要因であり、表面散乱を低減できることは大きな感度アップに繋がることになる。 Also in this case, the condensing lens 3a and the observation lens 4a are immersed in the liquid.
In this case, by using the condensing lens 3a as the liquid immersion, it is possible to eliminate the influence of the wavefront fluctuation that occurs when the sample 1 is moved.
Further, the influence of surface scattering (Haze) can be reduced. That is, since surface scattering is related to surface reflection, if it is configured as an immersion oblique incidence observation system, the influence of surface scattering can be reduced by about 35 to 50%. Surface scattering is a major impediment to the observation of internal defects, and the ability to reduce surface scattering leads to a significant increase in sensitivity.

この第３の実施形態である欠陥測定装置３００、及び、この欠陥測定装置３００によって実行される結晶欠陥測定方法によれば、第１の実施形態である欠陥測定装置１００、及び、この欠陥測定装置１００によって実行される結晶欠陥測定方法と同様の効果が得られる。   According to the defect measuring apparatus 300 according to the third embodiment and the crystal defect measuring method executed by the defect measuring apparatus 300, the defect measuring apparatus 100 according to the first embodiment and the defect measuring apparatus. The same effect as that of the crystal defect measurement method executed by 100 can be obtained.

以上、本発明の実施形態について説明したが、本発明は、かかる実施形態には限定されず、その要旨を逸脱しない範囲で種々変形が可能であることは言うまでもない。   As mentioned above, although embodiment of this invention was described, it cannot be overemphasized that this invention is not limited to this embodiment, A various deformation | transformation is possible in the range which does not deviate from the summary.

１００ 欠陥測定装置
１ 試料
２ レーザ発生部
３ 照射用光学系
３ａ 集光用レンズ
４ 観察用光学系
４ａ 観察用レンズ
５ 撮像部
６ 制御部
７ ＸＹＺステージ
８ａ，８ｂ，８ｃ，８ｄ 駆動部
９ 記憶部 DESCRIPTION OF SYMBOLS 100 Defect measuring apparatus 1 Sample 2 Laser generation part 3 Irradiation optical system 3a Condensing lens 4 Observation optical system 4a Observation lens 5 Imaging part 6 Control part 7 XYZ stage 8a, 8b, 8c, 8d Drive part 9 Storage part

Claims (6)

集光用レンズでビーム径を絞ったレーザ光を試料に照射し、当該試料の内部の欠陥によって散乱した散乱光を観察用レンズを介して撮像し当該撮像結果に基づいて当該試料の内部の欠陥を測定する欠陥測定装置において、
前記試料及び前記観察用レンズを液体で浸漬して、前記試料と前記観察用レンズとの間を前記液体で満たしたことを特徴とする欠陥測定装置。 The sample is irradiated with laser light whose beam diameter is reduced by the condensing lens, and the scattered light scattered by the defect inside the sample is imaged through the observation lens, and the defect inside the sample based on the imaging result In a defect measuring device for measuring
A defect measuring apparatus, wherein the sample and the observation lens are immersed in a liquid, and a space between the sample and the observation lens is filled with the liquid. 前記集光用レンズを前記液体で浸漬して、前記集光用レンズと前記試料との間を前記液体で満たしたことを特徴とする請求項１に記載の欠陥測定装置。   The defect measuring apparatus according to claim 1, wherein the condensing lens is immersed in the liquid and a space between the condensing lens and the sample is filled with the liquid. 前記レーザ光は前記試料の第１の面に照射され、前記第１の面と交差する第２の面からの前記散乱光を前記観察用レンズを介して撮像することを特徴とする請求項１又は請求項２に記載の欠陥測定装置。   2. The laser light is applied to a first surface of the sample, and the scattered light from a second surface intersecting the first surface is imaged through the observation lens. Or the defect measuring apparatus of Claim 2. 前記レーザ光は前記試料の第１の面に照射され、前記第１の面から出る前記散乱光を前記観察用レンズを介して撮像することを特徴とする請求項１又は請求項２に記載の欠陥測定装置。   The said laser beam is irradiated to the 1st surface of the said sample, The said scattered light emitted from the said 1st surface is imaged through the said observation lens, The Claim 1 or Claim 2 characterized by the above-mentioned. Defect measuring device. 前記液体は油であることを特徴とする請求項１から請求項４のいずれか一項に記載の欠陥測定装置。   The defect measuring apparatus according to claim 1, wherein the liquid is oil. 集光用レンズでビーム径を絞ったレーザ光を試料に照射し、当該試料の内部の欠陥によって散乱した散乱光を観察用レンズを介して撮像し当該撮像結果に基づいて当該試料の内部の欠陥を測定するにあたり、
前記集光用レンズを介して前記レーザ光を前記試料に照射し、前記試料との間を液体で満たした前記観察用レンズを介して前記散乱光を撮像することを特徴とする欠陥測定方法。 The sample is irradiated with laser light whose beam diameter is reduced by the condensing lens, and the scattered light scattered by the defect inside the sample is imaged through the observation lens, and the defect inside the sample based on the imaging result In measuring
A defect measurement method comprising: irradiating the sample with the laser light through the condensing lens, and imaging the scattered light through the observation lens filled with a liquid between the sample and the sample.
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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09246337A (en) * 1996-03-11 1997-09-19 Toshiba Microelectron Corp Method and device for detecting crystal defect
JPH11118728A (en) * 1997-10-17 1999-04-30 Kazama Engineering Kk Method and apparatus for visual inspection for work
JP2003329602A (en) * 2002-05-13 2003-11-19 Carl-Zeiss-Stiftung Method and apparatus for detecting defects in continuously moving strip of transparent material
JP2004061452A (en) * 2002-07-31 2004-02-26 Matsushita Electric Works Ltd Foreign matter inspection device and its method
JP2004259779A (en) * 2003-02-24 2004-09-16 Shin Etsu Handotai Co Ltd Method for evaluating wafer
JP2005083800A (en) * 2003-09-05 2005-03-31 Hitachi Ltd Flaw inspection method and flaw inspection device
JP2007064678A (en) * 2005-08-29 2007-03-15 Ratoc System Engineering Co Ltd Internal structure-of-specimen detection device and method for the same
JP2012181135A (en) * 2011-03-02 2012-09-20 Kobelco Kaken:Kk Internal defect inspection device and internal defect inspection method

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09246337A (en) * 1996-03-11 1997-09-19 Toshiba Microelectron Corp Method and device for detecting crystal defect
JPH11118728A (en) * 1997-10-17 1999-04-30 Kazama Engineering Kk Method and apparatus for visual inspection for work
JP2003329602A (en) * 2002-05-13 2003-11-19 Carl-Zeiss-Stiftung Method and apparatus for detecting defects in continuously moving strip of transparent material
US20030218743A1 (en) * 2002-05-13 2003-11-27 Klaus Gerstner Method and apparatus for detecting defects in a continuously moving strip of transparent material
JP2004061452A (en) * 2002-07-31 2004-02-26 Matsushita Electric Works Ltd Foreign matter inspection device and its method
JP2004259779A (en) * 2003-02-24 2004-09-16 Shin Etsu Handotai Co Ltd Method for evaluating wafer
JP2005083800A (en) * 2003-09-05 2005-03-31 Hitachi Ltd Flaw inspection method and flaw inspection device
JP2007064678A (en) * 2005-08-29 2007-03-15 Ratoc System Engineering Co Ltd Internal structure-of-specimen detection device and method for the same
JP2012181135A (en) * 2011-03-02 2012-09-20 Kobelco Kaken:Kk Internal defect inspection device and internal defect inspection method

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