TW202102841A - Detection apparatus and detection method thereof for effectively realizing the polarization state analysis of the signal light and realize a high-precision detection of the component under test in the longitudinal direction - Google Patents

Detection apparatus and detection method thereof for effectively realizing the polarization state analysis of the signal light and realize a high-precision detection of the component under test in the longitudinal direction Download PDF

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TW202102841A
TW202102841A TW108124552A TW108124552A TW202102841A TW 202102841 A TW202102841 A TW 202102841A TW 108124552 A TW108124552 A TW 108124552A TW 108124552 A TW108124552 A TW 108124552A TW 202102841 A TW202102841 A TW 202102841A
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light
detection
information
polarization
polarized light
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TW108124552A
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魯 陳
黃有為
崔高增
王天民
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大陸商深圳中科飛測科技有限公司
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Abstract

The invention provides a detection apparatus and method. The detection apparatus generates a signal light formed from an interference of a first echo light and a second echo light reflected from a surface of a component under test through a first probe device. The detection apparatus then obtains a first light intensity distribution information of the signal light corresponding to a sampling position on the component under test in order to further obtain a phase distribution of the signal light according to the intensity distribution, thereby obtaining defect distribution data of the device under test. The first probe device includes more than two polarization probes, or a non-polarization probe and at least one polarization probe. The invention can effectively realize the polarization state analysis of the signal light and realize a high-precision detection of the component under test in the longitudinal direction, so as to achieve a good reliability, a high stability and a fast detection speed.

Description

檢測設備及其檢測方法Testing equipment and testing method
本發明關於光學檢測技術領域,具體而言,關於一種檢測設備及方法。The present invention relates to the field of optical detection technology, and in particular, to a detection device and method.
晶圓缺陷檢測是指檢測晶圓中是否存在凹槽、顆粒、劃痕等缺陷以及缺陷位置。晶圓缺陷檢測應用十分廣泛,做為晶片基底,晶圓上存在缺陷將可能導致上面製作的昂貴工藝失效,因此晶圓生產方常進行缺陷檢測確保產品合格率,晶圓使用方也需要在使用前確定晶圓的缺陷程度以保證產品合格率;晶圓缺陷檢測還常用於測試半導體儀器是否存在附加污染。Wafer defect detection refers to the detection of defects such as grooves, particles, scratches, and the location of defects in the wafer. Wafer defect detection is widely used. As a wafer substrate, the presence of defects on the wafer may cause the expensive process to fail. Therefore, wafer producers often perform defect detection to ensure the product qualification rate, and wafer users also need to use it. Determining the degree of defects of the wafers to ensure the product qualification rate; wafer defect detection is also often used to test whether there is additional contamination in semiconductor equipment.
光學檢測方法具有檢測速度快、無附加污染的特點,被廣泛地應用在了元件的缺陷檢測中。然而,現有的用於檢測晶圓缺陷的光學檢測方法如光散射法在晶圓軸向(垂直於晶圓表面方向)上檢測精度低。The optical inspection method has the characteristics of fast inspection speed and no additional pollution, and is widely used in component defect inspection. However, the existing optical inspection methods for detecting wafer defects, such as the light scattering method, have low inspection accuracy in the axial direction of the wafer (direction perpendicular to the surface of the wafer).
鑒於此,本發明的目的在於提供一種缺陷檢測設備及方法,能夠有效地改善先前技術在晶圓軸向上檢測精度低的技術問題。In view of this, the purpose of the present invention is to provide a defect detection device and method, which can effectively improve the technical problem of low detection accuracy in the wafer axis in the prior art.
第一方面,本發明實施例提供了一種缺陷檢測設備,包括:光產生調製裝置和第一探測裝置。光產生調製裝置,用於產生第一偏振光和第二偏振光,使所述第一偏振光經待測元件的待測表面反射形成第一回波光,所述第二偏振光經待測元件表面反射形成第二回波光,並使所述第一回波光和第二回波光發生干涉,形成訊號光,其中,所述第一偏振光和第二偏振光中心之間具有預設剪切量。第一探測裝置,用於獲取所述訊號光的第一光強分布資訊,所述第一探測裝置包括兩個以上探測器,所述兩個以上探測器均為偏振探測器,且不同所述偏振探測器的偏振探測方向不同,或者,所述兩個以上探測器包括無偏振探測器和至少一個偏振探測器。In the first aspect, an embodiment of the present invention provides a defect detection device, including: a light generation modulation device and a first detection device. The light generating and modulating device is used to generate the first polarized light and the second polarized light, so that the first polarized light is reflected by the test surface of the test element to form first echo light, and the second polarized light passes through the test element The surface reflects to form a second echo light, and causes the first echo light and the second echo light to interfere to form a signal light, wherein there is a predetermined amount of shear between the centers of the first polarized light and the second polarized light . The first detection device is used to obtain the first light intensity distribution information of the signal light. The first detection device includes two or more detectors, and the two or more detectors are all polarization detectors, and are different from each other. The polarization detection directions of the polarization detectors are different, or the two or more detectors include a non-polarization detector and at least one polarization detector.
進一步地,所述第一探測裝置包括第一探測區,所述第一探測區用於對所述待測元件表面進行掃描;所述第一探測區包括多個第一探測單元區,所述多個第一探測單元區的排列方向與所述第一探測區在所述待測元件表面的掃描方向不垂直,各個所述探測器用於分別探測不同所述第一探測單元區對應的所述待測表面反射回的訊號光。Further, the first detection device includes a first detection area, the first detection area is used to scan the surface of the component under test; the first detection area includes a plurality of first detection unit areas, the The arrangement direction of the plurality of first detection unit areas is not perpendicular to the scanning direction of the first detection area on the surface of the component to be tested, and each of the detectors is used to detect the corresponding to different first detection unit areas. The signal light reflected back from the surface to be measured.
進一步地,所述多個第一探測單元區的排列方向平行於所述第一探測區對所述待測元件表面的掃描方向。Further, the arrangement direction of the plurality of first detection unit regions is parallel to the scanning direction of the first detection region on the surface of the component under test.
進一步地,所述第一探測區為條形,所述第一探測區的延伸方向垂直於所述第一探測區對所述待測元件表面的掃描方向。Further, the first detection area is strip-shaped, and the extension direction of the first detection area is perpendicular to the scanning direction of the first detection area to the surface of the component under test.
進一步地,當所述待測元件的待測表面為圓形時,所述第一探測區沿著所述待測元件表面的徑向延伸;所述第一探測區對所述待測元件待測表面的掃描方向垂直於所述待測表面的直徑方向。Further, when the surface to be measured of the component to be measured is circular, the first detection area extends along the radial direction of the surface of the component to be measured; The scanning direction of the measuring surface is perpendicular to the diameter direction of the surface to be measured.
進一步地,所述第一偏振光和第二偏振光用於在所述待測元件表面形成探測光斑;在沿所述第一探測區對所述待測元件表面的掃描方向上,所述探測光斑的尺寸大於或等於所述第一探測區的尺寸。Further, the first polarized light and the second polarized light are used to form a detection spot on the surface of the component under test; in the scanning direction of the surface of the component under test along the first detection area, the detection The size of the light spot is greater than or equal to the size of the first detection area.
進一步地,每個所述偏振探測器均為偏振線探測器,所述無偏振探測器為線探測器。採用偏振線探測器有利於增加單次採樣的檢測面積,進一步提高檢測效率。Further, each of the polarization detectors is a polarization line detector, and the non-polarization detector is a line detector. The use of polarization detectors is beneficial to increase the detection area of a single sampling and further improve the detection efficiency.
進一步地,所述偏振探測器的個數為兩個時,兩個所述偏振探測器的偏振探測方向相互垂直。Further, when the number of the polarization detectors is two, the polarization detection directions of the two polarization detectors are perpendicular to each other.
進一步地,當所述第一探測裝置包括三個及以上偏振探測器時,所述三個及以上偏振探測器包括第一偏振探測器、第二偏振探測器和第三偏振探測器,其中,所述第三偏振探測器和第一偏振探測器偏振探測方向之間的夾角等於360°/n,n 為大於等於3的整數,n為偏振探測器的個數。採用三個以上的偏振探測器能夠更精確地得到訊號光的相位資訊,以便得到更精確的高度測量結果。Further, when the first detection device includes three or more polarization detectors, the three or more polarization detectors include a first polarization detector, a second polarization detector, and a third polarization detector, wherein, The angle between the polarization detection direction of the third polarization detector and the first polarization detector is equal to 360°/n, n is an integer greater than or equal to 3, and n is the number of polarization detectors. Using more than three polarization detectors can obtain the phase information of the signal light more accurately, so as to obtain more accurate height measurement results.
進一步地,所述第一偏振探測器與第三偏振探測器的偏振探測方向垂直,所述第三偏振探測器與第二偏振探測器的偏振探測方向之間的夾角為45°。Further, the polarization detection directions of the first polarization detector and the third polarization detector are perpendicular, and the angle between the polarization detection directions of the third polarization detector and the second polarization detector is 45°.
進一步地,當所述第一探測裝置包括無偏振探測器和至少一個偏振探測器時,所述偏振探測器的個數為兩個及以上,其中兩個偏振探測器的偏振探測方向之間的夾角為銳角或鈍角。Further, when the first detection device includes a non-polarization detector and at least one polarization detector, the number of the polarization detectors is two or more, and the polarization detection directions of the two polarization detectors are different from each other. The included angle is acute or obtuse.
進一步地,所述光產生調製裝置包括: 第一光產生裝置,用於產生第一偏振光和第二偏振光,所述第一偏振光和第二偏振光中心之間具有預設剪切量,所述第一偏振光經待測元件表面反射形成第一回波光,所述第二偏振光經待測元件表面反射形成第二回波光,並使所述第一回波光束和第二回波光束合束; 偏振控制器,用於調製所述第一回波光束和第二回波光束的偏振方向,以使得所述第一回波光束和第二回波光束發生干涉,形成訊號光。Further, the light generating and modulating device includes: The first light generating device is used to generate the first polarized light and the second polarized light, the center of the first polarized light and the second polarized light has a preset shearing amount, and the first polarized light passes through the component under test. The surface is reflected to form a first echo light, the second polarized light is reflected on the surface of the component under test to form a second echo light, and the first echo beam and the second echo beam are combined; The polarization controller is used to modulate the polarization directions of the first echo beam and the second echo beam, so that the first echo beam and the second echo beam interfere to form signal light.
進一步地,所述第一光產生裝置包括探測光產生模組和光束調整模組,所述探測光產生模組和所述光束調整模組耦合; 所述探測光產生模組用於產生第一探測光; 所述光束調整模組用於將所述第一探測光分成所述第一偏振光和第二偏振光,並使所述第一回波光束和第二回波光束合束。Further, the first light generating device includes a probe light generating module and a beam adjusting module, and the probe light generating module is coupled with the beam adjusting module; The detection light generating module is used to generate the first detection light; The beam adjustment module is used to divide the first probe light into the first polarized light and the second polarized light, and combine the first echo beam and the second echo beam.
進一步地,所述探測光產生模組包括第一光源和擴束整形裝置,所述第一光源用於產生第一探測光,所述擴束整形裝置用於控制所述待測元件表面的光斑形狀和尺寸。Further, the probe light generating module includes a first light source and a beam expanding and shaping device, the first light source is used to generate the first probe light, and the beam expanding and shaping device is used to control the light spot on the surface of the component under test Shape and size.
進一步地,所述光束調整模組包括雙折射晶體。Further, the beam adjustment module includes a birefringent crystal.
進一步地,所述第一探測光為線偏振光、圓偏振光或橢圓偏振光。當探測光為線偏振光時,有利於簡化後續的解調過程。Further, the first detection light is linearly polarized light, circularly polarized light or elliptically polarized light. When the detection light is linearly polarized light, it is beneficial to simplify the subsequent demodulation process.
進一步地,所述缺陷檢測設備還包括第一處理裝置,所述第一探測裝置與所述第一處理裝置電連接。所述第一處理裝置用於根據所述訊號光的第一光強分布資訊獲取所述待測元件的缺陷資訊。Further, the defect detection equipment further includes a first processing device, and the first detection device is electrically connected to the first processing device. The first processing device is used for obtaining defect information of the component under test according to the first light intensity distribution information of the signal light.
進一步地,所述第一處理裝置包括: 訊號解調模組,用於根據所述訊號光的第一光強分布資訊獲取訊號光的初始資訊; 雜訊獲取模組,用於對所述訊號光的第一光強分布資訊進行低通濾波處理,獲取雜訊資訊; 目標資訊獲取模組,用於根據所述初始資訊以及雜訊資訊獲取所述待測元件的缺陷資訊。Further, the first processing device includes: The signal demodulation module is used to obtain the initial information of the signal light according to the first light intensity distribution information of the signal light; A noise acquisition module for performing low-pass filtering processing on the first light intensity distribution information of the signal light to acquire noise information; The target information acquisition module is used to acquire defect information of the component under test according to the initial information and noise information.
進一步地,所述初始資訊包括訊號光的初始相位資訊,所述雜訊資訊包括雜訊相位資訊。所述目標資訊獲取模組包括:目標相位獲取子模組,用於對所述初始相位資訊和所述雜訊相位資訊進行差值處理,獲取目標相位資訊;缺陷資訊獲取子模組,用於根據所述目標相位資訊獲取所述待測元件的缺陷資訊。這樣就可以濾除訊號光中包含的相位雜訊,有利於提高檢測結果的準確性。Further, the initial information includes initial phase information of the signal light, and the noise information includes noise phase information. The target information acquisition module includes: a target phase acquisition sub-module for performing difference processing on the initial phase information and the noise phase information to acquire target phase information; and a defect information acquisition sub-module for Obtain defect information of the component under test according to the target phase information. In this way, the phase noise contained in the signal light can be filtered out, which is beneficial to improve the accuracy of the detection result.
進一步地,所述目標資訊獲取模組還包括:缺陷標準庫,缺陷標準庫包括預設相位資訊和預設缺陷資訊,用於確定預設相位資訊與預設缺陷資訊之間的對應關係;所述缺陷資訊獲取子模組具體用於根據所述目標相位資訊在所述缺陷標準庫中進行查找,獲取相應的預設缺陷資訊,得到所述待測元件的缺陷資訊。Further, the target information acquisition module further includes: a defect standard library, which includes preset phase information and preset defect information, and is used to determine the correspondence between the preset phase information and the preset defect information; The defect information acquisition sub-module is specifically used to search in the defect standard library according to the target phase information, obtain corresponding preset defect information, and obtain defect information of the component under test.
進一步地,所述缺陷檢測設備還包括:第二探測裝置,用於收集所述待測元件表面的散射光,並獲取所述散射光的第二光強分布資訊;第二處理裝置,用於根據所述第一光強分布資訊獲取所述待測元件的第一缺陷資訊,根據所述第二光強分布資訊獲取所述待測元件的第二缺陷資訊,並基於所述第一缺陷資訊和所述第二缺陷資訊得到所述待測元件的目標缺陷資訊。這樣就可以實現雙通道檢測,有利於在提高缺陷檢測的縱向精度的基礎上,提高橫向解析度。Further, the defect detection equipment further includes: a second detection device for collecting scattered light on the surface of the component to be tested, and obtaining second light intensity distribution information of the scattered light; and a second processing device for Acquire first defect information of the component under test according to the first light intensity distribution information, obtain second defect information of the component under test according to the second light intensity distribution information, and based on the first defect information And the second defect information to obtain target defect information of the component under test. In this way, dual-channel detection can be realized, which is beneficial to improve the horizontal resolution on the basis of improving the longitudinal accuracy of defect detection.
進一步地,上述缺陷檢測設備還包括:第二光產生裝置,用於產生第二探測光,並使所述第二探測光經所述待測元件表面散射,形成所述散射光。Further, the above-mentioned defect detection equipment further includes: a second light generating device for generating second detection light, and causing the second detection light to be scattered by the surface of the component under test to form the scattered light.
第二方面,本發明實施例還提供了一種缺陷檢測方法,應用於上述第一方面提供的缺陷檢測裝置,所述方法包括:通過光產生調製裝置產生第一偏振光和第二偏振光,並使所述第一偏振光經待測元件的待測表面反射形成第一回波光,所述第二偏振光經所述待測表面反射形成第二回波光,其中,所述第一偏振光和第二偏振光中心之間具有預設剪切量;通過所述光產生調製裝置使所述第一回波光和第二回波光發生干涉,形成訊號光;通過第一探測裝置獲取所述訊號光沿多個不同偏振方向的光強資訊,或者獲取所述訊號光總的光強資訊以及至少沿一個偏振方向的光強資訊。In a second aspect, an embodiment of the present invention also provides a defect detection method, which is applied to the defect detection device provided in the above first aspect. The method includes: generating first polarized light and second polarized light through a light generating and modulating device, and The first polarized light is reflected by the surface to be measured of the component to be measured to form a first echo light, and the second polarized light is reflected by the surface to be measured to form a second echo light, wherein the first polarized light and There is a preset shearing amount between the centers of the second polarized light; the first echo light and the second echo light are interfered by the light generating and modulating device to form signal light; the signal light is obtained by the first detecting device The light intensity information along a plurality of different polarization directions, or the total light intensity information of the signal light and the light intensity information along at least one polarization direction are obtained.
進一步地,當所述第一探測裝置包括第一探測區,所述第一探測區包括多個第一探測單元區時;所述方法還包括:控制所述第一偏振光和第二偏振光在所述待測表面掃描,並重複形成訊號光和獲取光強資訊的步驟。Further, when the first detection device includes a first detection area, and the first detection area includes a plurality of first detection unit areas; the method further includes: controlling the first polarized light and the second polarized light Scan on the surface to be measured, and repeat the steps of forming signal light and obtaining light intensity information.
進一步地,所述第一偏振光和第二偏振光在所述待測表面的掃描方向與所述多個第一探測單元區的排列方向相同。Further, the scanning direction of the first polarized light and the second polarized light on the surface to be measured is the same as the arrangement direction of the plurality of first detection unit regions.
進一步地,獲取所述第一光強資訊的步驟包括:通過所述第一探測裝置對所述訊號光的光強進行採樣,相鄰兩次採樣的時間間隔內,所述第一探測區掃描的距離為掃描步長,相鄰所述第一探測單元區中心之間的距離等於所述掃描步長的整數倍。Further, the step of acquiring the first light intensity information includes: sampling the light intensity of the signal light by the first detection device, and within the time interval of two adjacent samples, the first detection area scans The distance of is the scanning step length, and the distance between the centers of adjacent first detection unit regions is equal to an integer multiple of the scanning step length.
進一步地,相鄰所述第一探測單元區中心之間的距離等於所述掃描步長。Further, the distance between the centers of adjacent first detection unit regions is equal to the scan step length.
進一步地,所述控制所述第一偏振光和第二偏振光在所述待測表面掃描的步驟包括:控制所述待測元件的待測表面沿與所述掃描方向相反的方向移動。Further, the step of controlling the scanning of the first polarized light and the second polarized light on the surface to be measured includes: controlling the surface to be measured of the component to be measured to move in a direction opposite to the scanning direction.
進一步地,所述控制所述待測元件的待測表面沿與所述掃描方向相反的方向移動的步驟包括:控制所述待測元件繞垂直於所述待測表面的轉軸旋轉。所述控制所述第一偏振光和第二偏振光在所述待測元件表面掃描的步驟還包括:當所述待測表面繞所述轉軸旋轉一周之後或者在所述待測表面繞所述轉軸旋轉的過程中,控制所述第一偏振光和第二偏振光在所述待測表面形成的光斑沿所述待測表面的直徑方向移動。Further, the step of controlling the surface to be tested of the component to be tested to move in a direction opposite to the scanning direction includes: controlling the component to be tested to rotate around a rotation axis perpendicular to the surface to be tested. The step of controlling the scanning of the first polarized light and the second polarized light on the surface of the component under test further includes: after the surface to be tested rotates one circle around the axis of rotation, or when the surface to be tested rotates around the During the rotation of the shaft, the light spot formed by the first polarized light and the second polarized light on the surface to be measured is controlled to move along the diameter direction of the surface to be measured.
進一步地,當光產生調製裝置包括第一光源和擴束整形裝置時,所述產生第一偏振光和第二偏振光的步驟包括:通過所述第一光源產生第一探測光,以基於所述第一探測光形成第一偏振光和第二偏振光;通過所述擴束整形裝置調整所述第一偏振光和第二偏振光在待測元件的待測表面所形成的光斑形狀和尺寸,使在沿所述第一探測區對所述待測元件表面的掃描方向上,所述探測光斑的尺寸大於或等於所述第一探測區的尺寸。Further, when the light generating and modulating device includes a first light source and a beam expander and shaping device, the step of generating the first polarized light and the second polarized light includes: generating the first probe light by the first light source to be based on the The first probe light forms a first polarized light and a second polarized light; the beam expander shaping device adjusts the shape and size of the spot formed by the first polarized light and the second polarized light on the surface to be measured of the component to be measured , So that the size of the detection spot is greater than or equal to the size of the first detection zone in the scanning direction of the surface of the component under test along the first detection zone.
進一步地,將所述第一探測裝置獲取到的所述訊號光沿多個不同偏振方向的光強資訊,或者所述訊號光總的光強資訊以及至少沿一個偏振方向的光強資訊作為所述訊號光的第一光強分布資訊。獲取到所述第一光強分布資訊之後,所述方法還包括:根據所述訊號光的第一光強分布資訊,獲取所述待測元件的缺陷資訊。Further, the light intensity information of the signal light along a plurality of different polarization directions, or the total light intensity information of the signal light and the light intensity information along at least one polarization direction obtained by the first detection device are used as the total light intensity information. The first light intensity distribution information of the signal light. After acquiring the first light intensity distribution information, the method further includes: acquiring defect information of the component under test according to the first light intensity distribution information of the signal light.
進一步地,所述根據所述訊號光的第一光強分布資訊,獲取所述待測元件的缺陷資訊包括:根據所述第一光強分布資訊獲取訊號光的初始資訊;對所述第一光強分布資訊進行低通濾波處理,獲取雜訊資訊;根據所述初始資訊以及雜訊資訊獲取所述待測元件的缺陷資訊。Further, the acquiring defect information of the device under test according to the first light intensity distribution information of the signal light includes: acquiring initial information of the signal light according to the first light intensity distribution information; The light intensity distribution information is processed by low-pass filtering to obtain noise information; and the defect information of the component under test is obtained according to the initial information and the noise information.
進一步地,所述初始資訊包括訊號光的初始相位資訊,所述雜訊資訊包括雜訊相位資訊。所述根據所述初始資訊以及雜訊資訊獲取所述待測元件的第一缺陷資訊包括:對所述初始相位資訊和所述雜訊相位資訊進行差值處理,獲取目標相位資訊;根據所述目標相位資訊獲取所述待測元件的缺陷資訊。Further, the initial information includes initial phase information of the signal light, and the noise information includes noise phase information. The obtaining the first defect information of the component under test according to the initial information and noise information includes: performing difference processing on the initial phase information and the noise phase information to obtain target phase information; Target phase information acquires defect information of the component under test.
進一步地,所述根據所述目標相位資訊獲取所述待測元件的缺陷資訊,包括:根據所述目標相位資訊,在預先配置的缺陷標準庫中進行查找相應的預設缺陷資訊,得到待測元件表面的第一缺陷資訊,其中,所述缺陷標準庫包括多個預設相位資訊與相應預設缺陷資訊之間的對應關係。Further, the acquiring defect information of the component to be tested according to the target phase information includes: searching for corresponding preset defect information in a pre-configured defect standard library according to the target phase information to obtain the defect information to be tested The first defect information on the surface of the component, wherein the defect standard library includes a plurality of correspondences between preset phase information and corresponding preset defect information.
本發明實施例提供的缺陷檢測設備,通過第一探測裝置待測元件表面反射的第一回波光和第二回波光發生干涉後形成的訊號光,得到待測元件上各採樣位置對應的訊號光在不同偏振方向上的強度分布,以進一步根據該強度分布得到訊號光的相位分布,從而得到待測元件的缺陷分布資料。其中,第一探測裝置包括兩個以上偏振探測器,或者無偏振探測器和至少一個偏振探測器,通過第一探測裝置能夠有效地實現訊號光的偏振態分析,實現待測元件在縱向(垂直於被測表面方向)上的高精度檢測,且可靠性好,穩定性高,檢測速度快。In the defect detection equipment provided by the embodiment of the present invention, the signal light formed after the interference of the first echo light and the second echo light reflected on the surface of the component under test by the first detection device is used to obtain the signal light corresponding to each sampling position on the component under test The intensity distribution in different polarization directions can further obtain the phase distribution of the signal light according to the intensity distribution, thereby obtaining the defect distribution data of the component under test. Among them, the first detection device includes two or more polarization detectors, or a non-polarization detector and at least one polarization detector. Through the first detection device, the polarization state analysis of the signal light can be effectively realized, and the component under test can be realized in the longitudinal direction (vertical direction). High-precision detection in the direction of the measured surface, with good reliability, high stability and fast detection speed.
為使本發明的上述目的、特徵和優點能更明顯易懂,下文特舉較佳實施例,並配合所附圖式,作詳細說明如下。In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, preferred embodiments are described in detail below in conjunction with the accompanying drawings.
為使本發明實施例的目的、技術方案和優點更加清楚,下面將結合本發明實施例中的圖式,對本發明實施例中的技術方案進行清楚、完整地描述,顯然,所描述的實施例是本發明一部分實施例,而不是全部的實施例。通常在此處圖式中描述和示出的本發明實施例的組件可以以各種不同的配置來布置和設計。In order to make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments These are a part of the embodiments of the present invention, but not all of the embodiments. The components of the embodiments of the present invention generally described and illustrated in the drawings herein may be arranged and designed in various different configurations.
因此,以下對在圖式中提供的本發明的實施例的詳細描述並非旨在限制要求保護的本發明的範圍,而是僅僅表示本發明的選定實施例。基於本發明中的實施例,本領域普通技術人員在沒有作出創造性勞動前提下所獲得的所有其他實施例,都屬於本發明保護的範圍。Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.
應注意到:相似的標號和字母在下面的圖式中表示類似項,因此,一旦某一項在一個圖式中被定義,則在隨後的圖式中不需要對其進行進一步定義和解釋。It should be noted that similar numbers and letters indicate similar items in the following figures. Therefore, once a certain item is defined in a figure, there is no need to further define and explain it in the following figures.
在本發明的描述中,需要說明的是,術語“中心”、“上”、“下”、“左”、“右”等指示的方位或位置關係為基於圖式所示的方位或位置關係,或者是該發明產品使用時慣常擺放的方位或位置關係,僅是為了便於描述本發明和簡化描述,而不是指示或暗示所指的裝置或元件必須具有特定的方位、以特定的方位構造和操作,因此不能理解為對本發明的限制。此外,術語“第一”、“第二”等僅用於區分描述,而不能理解為指示或暗示相對重要性。In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the diagram. , Or the position or positional relationship that the product of the invention is usually placed in use, is only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation and be constructed in a specific orientation And operation, therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", etc. are only used for distinguishing description, and cannot be understood as indicating or implying relative importance.
在本發明的描述中,還需要說明的是,除非另有明確的規定和限定,術語“設置”、“連接”、“耦合”應做廣義理解。例如,連接可以是固定連接,也可以是可拆卸連接,或一體地連接;可以是機械連接,也可以是電連接;可以是直接相連,也可以通過中間媒介間接相連,可以是兩個元件內部的連通。兩個器件之間耦合,表示由其中一個器件出射的光入射到另一個器件。對於本領域的普通技術人員而言,可以具體情況理解上述術語在本發明中的具體含義。In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "setting", "connection" and "coupling" should be interpreted in a broad sense. For example, the connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be inside two components.的连接。 Connectivity. The coupling between two devices means that the light emitted by one device is incident on the other device. For those of ordinary skill in the art, the specific meanings of the above-mentioned terms in the present invention can be understood in specific situations.
如圖1所示,本發明第一實施例提供了一種缺陷檢測設備1,包括:光產生調製裝置和第一探測裝置40。需要說明的是,本缺陷檢測設備1適用的待測元件60可以為晶圓,也可以是其他元件如鍍膜光學元件等。As shown in FIG. 1, the first embodiment of the present invention provides a defect detection device 1, which includes: a light generating and modulating device and a first detecting device 40. It should be noted that the component to be tested 60 applicable to the defect detection device 1 may be a wafer or other components such as a coated optical component.
其中,光產生調製裝置,用於產生第一偏振光和第二偏振光,使第一偏振光經待測元件60的待測表面反射形成第一回波光,第二偏振光經待測元件60表面反射形成第二回波光,並使第一回波光和第二回波光發生干涉,形成訊號光。其中,第一偏振光和第二偏振光中心之間具有預設剪切量。且於本發明一實施例中,第一偏振光和第二偏振光的傳播方向也一致。Among them, the light generating and modulating device is used to generate the first polarized light and the second polarized light, so that the first polarized light is reflected by the test surface of the test element 60 to form the first echo light, and the second polarized light passes through the test element 60. The surface reflects the second echo light, and causes the first echo light and the second echo light to interfere to form signal light. Wherein, there is a preset shear amount between the centers of the first polarized light and the second polarized light. In an embodiment of the present invention, the propagation directions of the first polarized light and the second polarized light are also the same.
具體來講,光產生調製裝置可以包括:第一光產生裝置和偏振控制器30,第一光產生裝置與偏振控制器30耦合,偏振控制器30與第一探測裝置40耦合。其中,第一光產生裝置,用於產生上述的第一偏振光和第二偏振光,使第一偏振光經待測元件60表面反射形成第一回波光,第二偏振光經待測元件60表面反射形成第二回波光,並使第一回波光束和第二回波光束合束後入射到偏振控制器30。偏振控制器30,用於調製第一回波光束和第二回波光束的偏振方向,第一回波光束和第二回波光束發生干涉,形成訊號光。Specifically, the light generating and modulating device may include: a first light generating device and a polarization controller 30, the first light generating device is coupled with the polarization controller 30, and the polarization controller 30 is coupled with the first detecting device 40. Among them, the first light generating device is used to generate the above-mentioned first polarized light and second polarized light, so that the first polarized light is reflected by the surface of the component under test 60 to form the first echo light, and the second polarized light passes through the component under test 60. The surface reflects the second echo light, and the first echo light beam and the second echo light beam are combined to enter the polarization controller 30. The polarization controller 30 is used to modulate the polarization directions of the first echo beam and the second echo beam, and the first echo beam and the second echo beam interfere to form signal light.
具體來講,如圖1所示,第一光產生裝置包括探測光產生模組10和光束調整模組20,探測光產生模組10和光束調整模組20之間耦合。其中,探測光產生模組10用於產生第一探測光。光束調整模組20用於將第一探測光分成上述第一偏振光和第二偏振光,使得第一偏振光和第二偏振光垂直入射到待測元件60的待測表面,並將第一偏振光經待測元件60反射形成的第一回波光和第二偏振光經待測元件60反射形成的第二回波光合束,使得合束後的第一回波光和第二回波光入射到偏振控制器30。具體的,探測光產生模組10產生的第一探測光進入光束調整模組20,經光束裝置模組處理形成上述第一偏振光和第二偏振光,入射到待測元件60的待測表面。第一偏振光經待測元件60反射形成的第一回波光和第二偏振光經待測元件60反射形成的第二回波光,經光束調整模組20合束後進入偏振控制器30。Specifically, as shown in FIG. 1, the first light generating device includes a probe light generating module 10 and a beam adjusting module 20, and the probe light generating module 10 and the beam adjusting module 20 are coupled. Among them, the detection light generating module 10 is used to generate the first detection light. The beam adjustment module 20 is used to divide the first probe light into the first polarized light and the second polarized light, so that the first polarized light and the second polarized light are perpendicularly incident on the surface to be measured of the component under test 60, and the first The first echo light formed by the reflection of the polarized light by the component under test 60 and the second echo light formed by the reflection of the second polarized light by the component under test 60 are combined, so that the combined first echo light and second echo light are incident on Polarization controller 30. Specifically, the first probe light generated by the probe light generating module 10 enters the beam adjustment module 20, is processed by the beam device module to form the first polarized light and the second polarized light, and is incident on the surface to be measured of the component under test 60 . The first echo light formed by the reflection of the first polarized light by the device under test 60 and the second echo light formed by the reflection of the second polarized light by the device under test 60 are combined by the beam adjustment module 20 and then enter the polarization controller 30.
本實施例中,第一探測光可以為單色光如532nm波長,光斑形狀以及尺寸可以根據具體需要設置,與探測裝置的探測區域適配。例如,可以採用圓光斑或矩形光斑等。作為一種可選的實施方式,探測光產生模組10產生的第一探測光為線偏振光。當然,在本發明的其他實施例中,第一探測光也可以是圓偏振光或橢圓偏振光,具體可以根據需要設置。In this embodiment, the first detection light may be monochromatic light such as a wavelength of 532 nm, and the shape and size of the light spot may be set according to specific needs and adapted to the detection area of the detection device. For example, a round spot or a rectangular spot can be used. As an optional implementation, the first detection light generated by the detection light generation module 10 is linearly polarized light. Of course, in other embodiments of the present invention, the first detection light may also be circularly polarized light or elliptically polarized light, which can be specifically set as required.
作為一種可選的實施方式,探測光產生模組10可以包括:第一光源101、擴束整形裝置102和偏振片103。其中,第一光源101用於產生初始光束。擴束整形裝置102用於將初始光束擴束整形為預設尺寸以及預設形狀的第一光束,以調節所形成的第一偏振光和第二偏振光在待測元件60表面的光斑尺寸和形狀。偏振片103用於調整第一光束的偏振態,形成具有預設偏振態的第二光束,從而控制所形成的第一偏振光和第二偏振光的偏振態。具體的,第一光源101發出的初始光束入射到擴束整形裝置102,經擴束整形裝置102的擴束、整形處理後形成第一光束。第一光束入射到偏振片103,由偏振片103出射的第二光束即為第一探測光。As an optional implementation manner, the probe light generating module 10 may include: a first light source 101, a beam expanding and shaping device 102, and a polarizer 103. Among them, the first light source 101 is used to generate the initial light beam. The beam expanding and shaping device 102 is used to expand and shape the initial beam into a first beam of a preset size and a preset shape, so as to adjust the spot size and size of the formed first polarized light and second polarized light on the surface of the component under test 60 shape. The polarizer 103 is used to adjust the polarization state of the first light beam to form a second light beam with a preset polarization state, thereby controlling the polarization states of the first polarized light and the second polarized light formed. Specifically, the initial light beam emitted by the first light source 101 is incident on the beam expanding and shaping device 102, and the first light beam is formed after the beam expanding and shaping processing by the beam expanding and shaping device 102. The first light beam is incident on the polarizer 103, and the second light beam emitted from the polarizer 103 is the first probe light.
需要說明的是,本實施例提供的缺陷檢測設備1對第一光源101單色性要求不高。因此,本實施例中,第一光源101可以採用雷射器,或者,第一光源101也可以包括LED光源和窄帶濾波片,LED光源發出的光束通過窄帶濾波片濾波後形成初始光束。It should be noted that the defect detection device 1 provided in this embodiment does not require high monochromaticity of the first light source 101. Therefore, in this embodiment, the first light source 101 may be a laser, or the first light source 101 may also include an LED light source and a narrow-band filter, and the light beam emitted by the LED light source is filtered by the narrow-band filter to form an initial light beam.
擴束整形裝置102可以由一個或多個透鏡以及光闌組成,具體結構可以根據實際採用的第一光源101以及所需要的光斑形狀和尺寸設置。本實施例中,經過擴束整形裝置102之後的光斑形狀可以為線光斑或矩形光斑,以方便對待測元件60的線區域進行檢測。當然,在本發明的其他實施例中,經過擴束整形裝置102之後的光斑也可以為其他形狀,如圓光斑或方形光斑等。The beam expanding and shaping device 102 may be composed of one or more lenses and a diaphragm, and the specific structure may be set according to the actual first light source 101 and the required spot shape and size. In this embodiment, the shape of the light spot after passing through the beam expanding and shaping device 102 may be a linear light spot or a rectangular light spot, so as to facilitate the detection of the line area of the component 60 under test. Of course, in other embodiments of the present invention, the light spot after passing through the beam expanding and shaping device 102 may also have other shapes, such as a round light spot or a square light spot.
偏振片103具體可以根據第一偏振光和第二偏振光的偏振態需求設置。於本發明一實施例中,偏振片103可以將擴束整形裝置102出射的光束調整為偏振方向與偏振片103的光軸夾角為45度的線偏振光。當然,在本發明其他實施例中,偏振片103可以將擴束整形裝置102出射的光束調整為其他方向的線偏振光,例如,與偏振片103的光軸夾角為30度的線偏振光、與偏振片103的光軸夾角為60度的線偏振光等,具體可以根據需要設置。The polarizer 103 can be specifically set according to the polarization state requirements of the first polarized light and the second polarized light. In an embodiment of the present invention, the polarizer 103 can adjust the beam emitted by the beam expanding and shaping device 102 to linearly polarized light whose polarization direction and the optical axis of the polarizer 103 are 45 degrees. Of course, in other embodiments of the present invention, the polarizer 103 can adjust the beam emitted by the beam expanding and shaping device 102 to linearly polarized light in other directions, for example, linearly polarized light with an angle of 30 degrees with the optical axis of the polarizer 103, Linearly polarized light having an angle of 60 degrees with the optical axis of the polarizer 103 can be specifically set as required.
另外,在本發明的其他實施例中,當第一光源101產生的初始光束對應的第一偏振光和第二偏振光在待測元件60表面的光斑形狀和尺寸均可以滿足需求時,則不需要對第一光源101發出的初始光束進行擴束和整形。此時,探測光產生模組10也可以不包括上述的擴束整形裝置102,僅包括第一光源101和偏振片103即可。或者,當第一光源101產生的初始光束對應的第一偏振光和第二偏振光在待測元件60表面的光斑面積較大,可以滿足需求,如第一光源101包括LED光源和窄帶濾波片時,則不需要再對其發出的初始光束進行擴束,只需要將光斑形狀整形為需要的形狀即可,此時探測光產生模組10可以包括:光源、光束整形元件和偏振片103,其中,光束整形元件可以採用光闌,用於對第一光源101發出的初始光束的光斑形狀進行整形。In addition, in other embodiments of the present invention, when the spot shape and size of the first polarized light and the second polarized light corresponding to the initial light beam generated by the first light source 101 on the surface of the device under test 60 can meet the requirements, it is not The initial light beam emitted by the first light source 101 needs to be expanded and shaped. At this time, the probe light generating module 10 may not include the aforementioned beam expanding and shaping device 102, and only include the first light source 101 and the polarizer 103. Or, when the first polarized light and the second polarized light corresponding to the initial light beam generated by the first light source 101 have a larger spot area on the surface of the component under test 60, the requirement can be met. For example, the first light source 101 includes an LED light source and a narrow-band filter. At this time, there is no need to expand the initial light beam it emits, only the shape of the light spot needs to be shaped to the required shape. At this time, the detection light generating module 10 may include: a light source, a beam shaping element and a polarizer 103, Wherein, the beam shaping element may adopt an aperture to shape the spot shape of the initial light beam emitted by the first light source 101.
於本發明一實施例中,上述第一偏振光和第二偏振光可以均為線偏振光,且偏振方向相互垂直。此時,光束調整模組20具體可以包括雙折射晶體202和物鏡203,如圖1所示。In an embodiment of the present invention, the first polarized light and the second polarized light may both be linearly polarized light, and the polarization directions are perpendicular to each other. At this time, the beam adjustment module 20 may specifically include a birefringent crystal 202 and an objective lens 203, as shown in FIG. 1.
其中,雙折射晶體202用於基於雙折射效應,將第一探測光分為具有微小夾角且偏振方向相互垂直的兩束線偏振光。由於晶體材料各向異性,這兩束折射光線的夾角大小與光波的傳播方向以及偏振狀態有關。為了儘量減小兩束折射光線的夾角,使得第一偏振光和第二偏振光的橫向剪切量儘量小,從而提高檢測精度。作為一種實施方式,雙折射晶體202可以採用Nomarski稜鏡。當然,在本發明的其他實施例中,也可以採用其他適用的雙折射晶體202。需要說明的是,當探測光的振動方向與光軸夾角為45度角方向時,第一偏振光和第二偏振光的光強相等,有利於簡化後續的訊號處理。Among them, the birefringent crystal 202 is used to divide the first probe light into two linearly polarized lights with a small included angle and polarization directions perpendicular to each other based on the birefringence effect. Due to the anisotropy of the crystal material, the angle between the two refracted rays is related to the propagation direction and polarization state of the light wave. In order to reduce the angle between the two refracted rays as much as possible, the transverse shear of the first polarized light and the second polarized light is as small as possible, thereby improving the detection accuracy. As an implementation manner, the birefringent crystal 202 may use Nomarski 鏡. Of course, in other embodiments of the present invention, other suitable birefringent crystals 202 can also be used. It should be noted that when the angle between the vibration direction of the probe light and the optical axis is 45 degrees, the light intensity of the first polarized light and the second polarized light are equal, which is beneficial to simplify subsequent signal processing.
物鏡203可以由一個或多個透鏡組成,用於將由雙折射晶體202出射的兩束傳播方向具有微小夾角、且偏振方向相互垂直的線偏振光轉化為兩束具有預設剪切量的平行光,即為上述的第一偏振光和第二偏振光。The objective lens 203 can be composed of one or more lenses, and is used to convert the two linearly polarized light beams emitted by the birefringent crystal 202 whose propagation directions have a small included angle and the polarization directions are perpendicular to each other into two parallel light beams with a preset shearing amount. , Which is the above-mentioned first polarized light and second polarized light.
當然,為了合理布置光路,光束調整模組20除了包括雙折射晶體202和物鏡203以外,還可以包括第一分束器201,如圖1所示。本實施例中,第一分束器201可以採用半透半反鏡。Of course, in order to reasonably arrange the optical path, the beam adjustment module 20 may include a first beam splitter 201 in addition to the birefringent crystal 202 and the objective lens 203, as shown in FIG. 1. In this embodiment, the first beam splitter 201 may be a half mirror.
作為一種實施方式,第一分束器201、雙折射晶體202和物鏡203依次設置於探測光產生模組10與待測元件60之間的光傳播路徑上。此時,探測光產生模組10產生的第一探測光經第一分束器201入射到雙折射晶體202,被分成具有微小夾角且偏振方向相互垂直的兩束線偏振光,兩束線偏振光繼續通過物鏡203後,形成上述的第一偏振光和第二偏振光,入射到待測元件60表面。第一偏振光經待測元件60表面反射形成第一回波光,第二偏振光經待測元件60表面反射形成的第二回波光,第一回波光和第二回波光沿原路返回,經物鏡203進入雙折射晶體202,在雙折射晶體202中重新複合共線後,透過第一分束器201入射到偏振控制器30。可以理解的是,由待測元件60反射回的第一回波光和第二回波光重新複合共線後,各自的偏振方向保持不變。As an embodiment, the first beam splitter 201, the birefringent crystal 202, and the objective lens 203 are sequentially arranged on the light propagation path between the probe light generating module 10 and the component under test 60. At this time, the first detection light generated by the detection light generation module 10 enters the birefringent crystal 202 through the first beam splitter 201, and is divided into two linearly polarized light beams with a small included angle and polarization directions perpendicular to each other. After the light continues to pass through the objective lens 203, the above-mentioned first polarized light and second polarized light are formed, and are incident on the surface of the component under test 60. The first polarized light is reflected on the surface of the component under test 60 to form the first echo light, and the second polarized light is reflected on the surface of the component under test 60 to form the second echo light. The first and second echo lights return along the original path. The objective lens 203 enters the birefringent crystal 202, and after recombining collinear in the birefringent crystal 202, it enters the polarization controller 30 through the first beam splitter 201. It can be understood that after the first echo light and the second echo light reflected by the component under test 60 are recombined and collinear, the respective polarization directions remain unchanged.
本實施例中,偏振控制器30用於調節上述的第一回波光和第二回波光的偏振方向。所述第一回波光和第二回波光發生干涉,形成訊號光。具體的,偏振控制器30調節入射的複合光的偏振方向,能夠簡化後續通過第一光強分布資訊獲取第一回波光和第二回波光的計算複雜度,提高檢測效率和精度。本實施例中,偏振控制器30可以採用四分一波片、二分之一波片或者四分一波片和二分之一波片的組合等。In this embodiment, the polarization controller 30 is used to adjust the polarization directions of the first echo light and the second echo light described above. The first echo light and the second echo light interfere to form signal light. Specifically, the polarization controller 30 adjusts the polarization direction of the incident composite light, which can simplify the subsequent calculation complexity of obtaining the first echo light and the second echo light through the first light intensity distribution information, and improve the detection efficiency and accuracy. In this embodiment, the polarization controller 30 may adopt a quarter-wave plate, a half-wave plate, or a combination of a quarter-wave plate and a half-wave plate.
例如,當由待測元件60反射回的第一回波光和第二回波光為偏振方向相互垂直的線偏振光,且偏振控制器30採用四分之一波片時,當複合光的偏振方向和四分之一波片的光軸面成45度角時,複合光中所包含的第一回波光和第二回波光分別轉換為不同方向旋轉的圓偏振光,即左旋光和右旋光。For example, when the first echo light and the second echo light reflected by the component under test 60 are linearly polarized light whose polarization directions are perpendicular to each other, and the polarization controller 30 adopts a quarter wave plate, when the polarization direction of the composite light is When it is at a 45-degree angle to the optical axis of the quarter-wave plate, the first echo light and the second echo light contained in the composite light are respectively converted into circularly polarized light that rotates in different directions, that is, left-handed light and right-handed light. .
本實施例中,第一探測裝置40用於獲取通過光產生調製裝置形成的訊號光的第一光強分布資訊。具體的,第一探測裝置40包括兩個以上探測器。In this embodiment, the first detecting device 40 is used to obtain the first light intensity distribution information of the signal light formed by the light generating and modulating device. Specifically, the first detection device 40 includes more than two detectors.
如圖2所示,第一探測裝置40包括第一探測區。第一探測區是指第一探測裝置40的工作面即光敏面投射在待測元件60的待測表面的區域,即光敏面經第一探測裝置40與待測元件60之間的光學器件在待測表面所成的像所在區域。需要說明的是,圖2示出的投射關係示意圖僅為示意,第一探測裝置40與待測元件60之間還設置有其他光學器件,如物鏡203、光折射晶體、偏振控制器30等。第一探測區內的待測表面反射回的第一回波光和第二回波光所形成的訊號光能夠被第一探測裝置40的工作面接收。具體來講,由於第一探測裝置40包括兩個以上探測器,第一探測區也相應包括多個第一探測單元區,一個探測器對應於一個第一探測單元區。在檢測過程中的同一時刻,各個探測器分別探測不同第一探測單元區內的待測表面反射回的第一回波光和第二回波光所形成的訊號光。As shown in FIG. 2, the first detection device 40 includes a first detection area. The first detection zone refers to the area where the working surface of the first detection device 40, that is, the photosensitive surface, is projected on the surface to be measured of the component to be measured 60, that is, the photosensitive surface is located between the first detection device 40 and the component to be measured 60 through the optical device. The area where the image formed by the surface to be measured is located. It should be noted that the projection relationship diagram shown in FIG. 2 is only for illustration, and other optical devices such as objective lens 203, light refraction crystal, polarization controller 30, etc. are arranged between the first detection device 40 and the component under test 60. The signal light formed by the first echo light and the second echo light reflected from the surface to be measured in the first detection zone can be received by the working surface of the first detection device 40. Specifically, since the first detection device 40 includes more than two detectors, the first detection area also includes a plurality of first detection unit areas, and one detector corresponds to one first detection unit area. At the same moment in the detection process, each detector detects the signal light formed by the first echo light and the second echo light reflected back from the surface to be tested in the different first detection unit areas.
例如,如圖2所示,假設第一探測裝置40包括第一探測器41、第二探測器42、第三探測器43和第四探測器44,第一探測器41對應於第一探測單元區P1,第二探測器42對應於第一探測單元區P2,第三探測器43對應於第一探測單元區P3,第四探測器44對應於第一探測單元區P4。則在同一時刻,第一探測器41用於探測第一探測單元區P1內的待測表面600反射回的第一回波光和第二回波光所形成的訊號光,第二探測器42用於探測第二探測單元區P2內的待測表面600反射回的第一回波光和第二回波光所形成的訊號光,第三探測器43用於探測第三探測單元區P3內的待測表面600反射回的第一回波光和第二回波光所形成的訊號光,第四探測器44用於探測第四探測單元區P4內的待測表面600反射回的第一回波光和第二回波光所形成的訊號光。For example, as shown in FIG. 2, suppose that the first detection device 40 includes a first detector 41, a second detector 42, a third detector 43, and a fourth detector 44, and the first detector 41 corresponds to the first detection unit. In area P1, the second detector 42 corresponds to the first detection unit area P2, the third detector 43 corresponds to the first detection unit area P3, and the fourth detector 44 corresponds to the first detection unit area P4. At the same moment, the first detector 41 is used to detect the signal light formed by the first echo light and the second echo light reflected back from the surface to be measured 600 in the first detection unit area P1, and the second detector 42 is used Detect the signal light formed by the first echo light and the second echo light reflected back from the surface to be measured 600 in the second detection unit area P2, and the third detector 43 is used to detect the surface to be measured in the third detection unit area P3 The signal light formed by the first echo light and the second echo light reflected back by 600, the fourth detector 44 is used to detect the first echo light and the second echo light reflected back by the surface to be measured 600 in the fourth detection unit area P4 Signal light formed by wave light.
檢測時,需要控制第一探測區401在待測元件60的待測表面600掃描,使得待測表面600同一檢測區域反射回的第一回波光和第二回波光所形成的訊號光,隨著掃描時間的先後依次被每個探測器接收,也就是使得待測表面600同一檢測區域對應的訊號光在各探測器的工作面上掃描。例如,當需要檢測待測元件60的待測表面600某預設檢測區域的缺陷情況時,需要控制第一探測區401沿預設軌跡對該檢測區域進行掃描,使得每個探測器均能獲取到該檢測區域反射回的第一回波光和第二回波光所形成的訊號光。During detection, the first detection area 401 needs to be controlled to scan the surface 600 of the component under test 60, so that the signal light formed by the first echo light and the second echo light reflected back from the same detection area of the surface 600 is followed by The scanning time is sequentially received by each detector, that is, the signal light corresponding to the same detection area of the surface 600 to be tested is scanned on the working surface of each detector. For example, when it is necessary to detect defects in a predetermined detection area of the surface 600 to be tested, the first detection area 401 needs to be controlled to scan the detection area along the preset trajectory, so that each detector can obtain Signal light formed by the first echo light and the second echo light reflected back to the detection area.
具體來講,控制第一探測區401在待測元件60的待測表面掃描的方式可以為:在光路搭建好後,保持第一偏振光和第二偏振光的入射位置以及第一探測裝置40的位置不變,控制待測元件60沿預設軌跡運動,從而使得第一偏振光和第二偏振光在待測元件60的待測表面形成的探測光斑對待測表面進行掃描,也即使得第一探測裝置40對應的第一探測區401對待測表面進行掃描。當然,在本發明的其他實施方式中,也可以在光路搭建好、且放置好待測元件60後,保持待測元件60不動,同步控制第一偏振光和第二偏振光的入射位置以及第一探測區401相對於待測元件60的待測表面運動,使得第一探測區401對待測表面進行掃描。Specifically, the method of controlling the scanning of the first detection area 401 on the surface to be measured of the component under test 60 may be: after the optical path is built, the incident positions of the first polarized light and the second polarized light and the first detection device 40 are maintained. The position of the component under test 60 is not changed, and the component under test 60 is controlled to move along the preset trajectory, so that the detection spot formed by the first polarized light and the second polarized light on the surface under test of the component under test 60 scans the surface to be tested, that is, the first A first detection area 401 corresponding to a detection device 40 scans the surface to be measured. Of course, in other embodiments of the present invention, after the optical path is built and the component under test 60 is placed, the component under test 60 can be kept still, and the incident positions of the first polarized light and the second polarized light and the first polarized light can be controlled synchronously. A detection area 401 moves relative to the surface to be measured of the component under test 60, so that the first detection area 401 scans the surface to be measured.
可以理解的是,在掃描過程中,為了使得每個探測器均能接收到待測元件60表面的預設檢測區域對應的訊號光,上述多個第一探測單元區的排列方向與第一探測區401在待測元件60表面的掃描方向應不垂直。作為一種可選的實施方式,上述多個第一探測單元區的排列方向平行於第一探測區401對待測元件60表面的掃描方向,以便於各探測器在掃描過程中能更好地接收預設檢測區域對應的訊號光,從而提高檢測效率。It is understandable that in the scanning process, in order to enable each detector to receive the signal light corresponding to the preset detection area on the surface of the component to be tested 60, the arrangement direction of the plurality of first detection unit areas is the same as that of the first detection area. The scanning direction of the area 401 on the surface of the component under test 60 should not be perpendicular. As an optional implementation, the arrangement direction of the multiple first detection unit areas is parallel to the scanning direction of the first detection area 401 on the surface of the component 60 to be tested, so that each detector can better receive the pre-detection during the scanning process. Set the signal light corresponding to the detection area to improve the detection efficiency.
具體的,本實施例中,所述第一探測器41、第二探測器42、第三探測器43和第四探測器44的排列方向與多個第一探測單元區的排列方向相同,則所述第一探測器41、第二探測器42、第三探測器43和第四探測器44的排列方向平行於所述第一探測區401對待測元件60表面的掃描方向。Specifically, in this embodiment, the arrangement direction of the first detector 41, the second detector 42, the third detector 43, and the fourth detector 44 is the same as the arrangement direction of the multiple first detection unit regions, then The arrangement direction of the first detector 41, the second detector 42, the third detector 43 and the fourth detector 44 is parallel to the scanning direction of the surface of the component 60 under test in the first detection area 401.
為了進一步提高檢測效率,作為一種可選的實施方式,第一探測裝置40所對應的第一探測區為條形,且第一探測區包括的多個第一探測單元區也均為條形。第一探測區的延伸方向垂直於第一探測區對所述待測元件60表面的掃描方向。這樣就能夠增加一次掃描所能檢測到的元件區域,從而提高檢測效率。In order to further improve the detection efficiency, as an optional implementation manner, the first detection area corresponding to the first detection device 40 is strip-shaped, and the plurality of first detection unit areas included in the first detection area are also strip-shaped. The extension direction of the first detection area is perpendicular to the scanning direction of the first detection area to the surface of the component under test 60. In this way, it is possible to increase the component area that can be detected by one scan, thereby improving the detection efficiency.
當待測元件60的待測表面為圓形時,第一探測區沿著待測元件60表面的徑向延伸。此時,第一探測區在待測元件60的待測表面的掃描方向垂直於待測表面的直徑方向。When the surface to be tested of the component to be tested 60 is circular, the first detection area extends along the radial direction of the surface of the component to be tested 60. At this time, the scanning direction of the first detection area on the surface to be tested of the component to be tested 60 is perpendicular to the diameter direction of the surface to be tested.
檢測時,第一偏振光和第二偏振光在待測元件60的待測表面形成探測光斑,該探測光斑應覆蓋或部分覆蓋第一探測裝置40對應的第一探測區。作為一種可選的實施方式,在沿第一探測區對待測元件60表面的掃描方向上,探測光斑的尺寸大於或等於第一探測區的尺寸。例如,第一探測區為長條形時,探測光斑的形狀為長方形,當第一探測區對待測元件60表面的掃描方向與探測光斑的寬度方向一致時,探測光斑的寬度大於或等於第一探測區的寬度。During detection, the first polarized light and the second polarized light form a detection spot on the surface to be measured of the component under test 60, and the detection spot should cover or partially cover the first detection area corresponding to the first detection device 40. As an optional implementation, the size of the detection spot is greater than or equal to the size of the first detection zone in the scanning direction along the surface of the component to be tested 60 in the first detection zone. For example, when the first detection area is a long strip, the shape of the detection spot is a rectangle. When the scanning direction of the surface of the first detection area is consistent with the width direction of the detection spot, the width of the detection spot is greater than or equal to the first detection spot. The width of the detection area.
探測光斑的尺寸大於或等於第一探測區的尺寸能夠使第一探測裝置40所包括的各探測器同時獲取不同第一探測單元區反射的訊號光的光強,從而能夠提高檢測效率。The size of the detection spot is greater than or equal to the size of the first detection area, so that the detectors included in the first detection device 40 can simultaneously obtain the light intensity of the signal light reflected by different first detection unit areas, thereby improving the detection efficiency.
作為一種可選的方式,上述兩個以上探測器均為偏振探測器,每個偏振探測器用於探測訊號光特定偏振方向的強度,且不同偏振探測器的偏振探測方向不同。需要說明的是,偏振探測方向是指偏振探測器能夠探測到的光的偏振方向。因此,兩個以上偏振探測器可以用於獲取由偏振控制器30出射的訊號光在不同偏振方向上的強度。通過兩個以上的偏振探測器探測訊號光在不同偏振方向的強度分布,即可以進一步根據該強度分布得到訊號光的相位值,從而根據訊號光的相位值得到待測元件60表面的高度分布。可以理解的是,待測元件60上第一偏振光和第二偏振光的照射位置間的高度差將改變反射光相位值,因此,待測元件60表面的高度分布將影響訊號光的相位分布。As an optional manner, the above two or more detectors are polarization detectors, and each polarization detector is used to detect the intensity of a specific polarization direction of the signal light, and the polarization detection directions of different polarization detectors are different. It should be noted that the polarization detection direction refers to the polarization direction of light that can be detected by the polarization detector. Therefore, two or more polarization detectors can be used to obtain the intensity of the signal light emitted by the polarization controller 30 in different polarization directions. By detecting the intensity distribution of the signal light in different polarization directions by more than two polarization detectors, the phase value of the signal light can be further obtained according to the intensity distribution, and the height distribution of the surface of the component under test 60 can be obtained according to the phase value of the signal light. It is understandable that the height difference between the irradiation positions of the first polarized light and the second polarized light on the component under test 60 will change the phase value of the reflected light. Therefore, the height distribution of the surface of the component under test 60 will affect the phase distribution of the signal light. .
本實施例中,可以通過在光電探測器上方加入微刻陣列構成偏振探測器,微刻陣列用於使得訊號光特定偏振方向的分量通過,從而實現特定偏振方向的訊號光從微刻陣列起偏通過被探測器接收。不同偏振探測器中的微刻陣列的透振方向不同,從而使得不同偏振探測器能夠獲取訊號光不同偏振方向上的強度。In this embodiment, a polarization detector can be formed by adding a micro-engraved array above the photodetector. The micro-engraved array is used to pass components of the signal light in a specific polarization direction, so that the signal light in a specific polarization direction is polarized from the micro-engraved array. By being received by the detector. The vibration transmission directions of the micro-engraved arrays in different polarization detectors are different, so that different polarization detectors can obtain the intensity of the signal light in different polarization directions.
第一探測裝置40具體包括的偏振探測器數量以及各偏振探測器的偏振探測方向可以根據元件缺陷檢測需求確定。例如,第一探測裝置40可以包括兩個偏振探測器、三個偏振探測器或四個偏振探測器等。The number of polarization detectors specifically included in the first detection device 40 and the polarization detection direction of each polarization detector can be determined according to the component defect detection requirements. For example, the first detection device 40 may include two polarization detectors, three polarization detectors, or four polarization detectors.
需要說明的是,當第一探測裝置40包括兩個偏振探測器時,兩個偏振探測器的偏振探測方向相互垂直。此時,無法辨別缺陷類型是凸起還是凹陷(即無法辨別相位符號),採用三個或三個以上的偏振探測器則可以辨別缺陷類型。因此,於本發明一實施例中,第一探測裝置40可以包括三個以上偏振探測器。當第一探測裝置40包括三個及以上偏振探測器時,三個及以上偏振探測器至少包括第一偏振探測器、第二偏振探測器和第三偏振探測器。其中,第三偏振探測器和第一偏振探測器偏振探測方向之間的夾角等於360°/n,n表示偏振探測器的個數,且n為大於等於3的整數。作為一種可選的實施方式,第一偏振探測器與第三偏振探測器的偏振探測方向垂直,第三偏振探測器與第二偏振探測器的偏振探測方向之間的夾角為45°,這樣有利於簡化後續的相位解調。It should be noted that when the first detection device 40 includes two polarization detectors, the polarization detection directions of the two polarization detectors are perpendicular to each other. At this time, it is impossible to distinguish whether the defect type is convex or concave (that is, the phase sign cannot be distinguished), and the defect type can be distinguished by using three or more polarization detectors. Therefore, in an embodiment of the present invention, the first detection device 40 may include more than three polarization detectors. When the first detection device 40 includes three or more polarization detectors, the three or more polarization detectors include at least a first polarization detector, a second polarization detector, and a third polarization detector. Wherein, the angle between the polarization detection direction of the third polarization detector and the first polarization detector is equal to 360°/n, n represents the number of polarization detectors, and n is an integer greater than or equal to 3. As an optional implementation manner, the polarization detection directions of the first polarization detector and the third polarization detector are perpendicular, and the angle between the polarization detection directions of the third polarization detector and the second polarization detector is 45°, which is advantageous To simplify the subsequent phase demodulation.
例如,在本發明的一種應用場景中,第一探測裝置40包括四個偏振線探測器,偏振探測方向分別為0度、45度、90度和135度,如圖3所示。For example, in an application scenario of the present invention, the first detection device 40 includes four polarization line detectors, and the polarization detection directions are 0 degrees, 45 degrees, 90 degrees, and 135 degrees, as shown in FIG. 3.
為了進一步提高檢測效率,於本發明一實施例中,每個偏振探測器均採用偏振線探測器,即利用偏振線探測器陣列實現訊號光在不同偏振方向的強度測量。這樣有利於增加單次採樣的檢測面積,進一步提高檢測效率。相應的,本實施例中,在垂直於第一探測單元區排列方向上,所述探測光斑的尺寸大於等於所述第一探測區的尺寸,能夠增加探測效率。In order to further improve the detection efficiency, in an embodiment of the present invention, each polarization detector adopts a polarization detector, that is, an array of polarization detectors is used to measure the intensity of signal light in different polarization directions. This is beneficial to increase the detection area of a single sampling and further improve the detection efficiency. Correspondingly, in this embodiment, in the arrangement direction perpendicular to the first detection unit area, the size of the detection spot is greater than or equal to the size of the first detection area, which can increase the detection efficiency.
可以理解的是,每個偏振線探測器由多個偏振探測單元組成。例如,當一個偏振探測單元的工作面形狀為正方形即對應的第一探測單元區的形狀也為正方形時,一個偏振線探測器的工作面為由多個正方形區域線性排列組成的區域。當待測元件60的檢測區域為圓形時,如當待測元件60為晶圓時,偏振線探測器的工作面沿著晶圓的徑向延伸。當然,在本發明的其他實施例中,每個偏振探測器也可以由一個偏振探測單元組成。具體的,可以在單個的光電探測單元上方加上一個或多個微刻單元構成一個偏振探測單元,該微刻單元也用於使得訊號光特定偏振方向的分量通過,被對應的光電探測單元接收。需要說明的是,上述的微刻陣列可以由多個微刻單元組成。It can be understood that each polarization detector is composed of multiple polarization detection units. For example, when the shape of the working surface of a polarization detection unit is square, that is, the shape of the corresponding first detection unit area is also square, the working surface of a polarization detector is an area composed of a plurality of square areas linearly arranged. When the detection area of the component under test 60 is circular, such as when the component under test 60 is a wafer, the working surface of the polarization detector extends along the radial direction of the wafer. Of course, in other embodiments of the present invention, each polarization detector may also be composed of a polarization detection unit. Specifically, one or more micro-engraving units can be added above a single photodetection unit to form a polarization detection unit. The micro-engraving unit is also used to pass the component of the signal light in a specific polarization direction and be received by the corresponding photodetection unit. . It should be noted that the above-mentioned micro-engraving array may be composed of multiple micro-engraving units.
作為另一種可選的方式,上述第一探測裝置40包括無偏振探測器和至少一個偏振探測器。需要說明的是,無偏振探測器是指能夠獲取任意偏振方向的光束的強度資訊的探測器;偏振探測器是指僅能獲取特定偏振方向的光束的強度資訊的探測器。其中,偏振探測器的個數可以為一個,假設該偏振探測器的偏振探測方向為α,通過該偏振探測器獲取的一檢測區域對應的訊號光的光強資訊以及無偏振探測器所獲取的該檢測區域對應的訊號光在α偏振方向上的光強資訊,就能夠得到該檢測區域對應的訊號光在與α正交的β偏振方向上的光強資訊,從而根據該檢測區域對應的訊號光在α偏振方向上的光強資訊以及在β偏振方向上的光強資訊,就可以得到該檢測區域對應的訊號光的相位資訊,從而得到該檢測區域的缺陷情況。當然,偏振探測器的個數也可以為兩個及以上,此時,當兩個偏振探測器的偏振探測方向之間的夾角為銳角或鈍角時,能夠辨別缺陷類型是凸起還是凹陷。As another optional manner, the above-mentioned first detection device 40 includes a non-polarization detector and at least one polarization detector. It should be noted that a non-polarization detector refers to a detector that can obtain intensity information of light beams in any polarization direction; a polarization detector refers to a detector that can only obtain intensity information of light beams in a specific polarization direction. Among them, the number of polarization detectors can be one, assuming that the polarization detection direction of the polarization detector is α, the intensity information of the signal light corresponding to a detection area obtained by the polarization detector and the information obtained by the non-polarization detector The light intensity information of the signal light corresponding to the detection area in the α polarization direction can be used to obtain the light intensity information of the signal light corresponding to the detection area in the β polarization direction orthogonal to α, and then according to the signal corresponding to the detection area The light intensity information in the α polarization direction and the light intensity information in the β polarization direction can obtain the phase information of the signal light corresponding to the detection area, thereby obtaining the defect status of the detection area. Of course, the number of polarization detectors can also be two or more. In this case, when the angle between the polarization detection directions of the two polarization detectors is an acute or obtuse angle, it can be distinguished whether the defect type is convex or concave.
另外,當第一探測裝置40包括無偏振探測器和至少一個偏振探測器時,為了提高檢測效率,每個偏振探測器均為偏振線探測器,且無偏振探測器也為線探測器。In addition, when the first detection device 40 includes a non-polarization detector and at least one polarization detector, in order to improve the detection efficiency, each polarization detector is a polarization detector, and the non-polarization detector is also a line detector.
另外,可以理解的是,對待測元件60進行檢測時,需要將待測元件60放置於載物台50上。作為一種可選的實施方式,如圖1所示,本發明實施例提供的缺陷檢測設備1還包括載物台50,用於放置待測元件60。進一步地,為了實現對待測元件60的線掃描,作為一種掃描方式,載物台50可以不僅用於放置待測元件60,還可以用於帶動待測元件60運動。具體的,載物台50可以是電動平移台,可以是手動平移台。當然,為了更準確地控制掃描過程,優選採用電動平移台。於本發明一實施例中,若以載物台50的置物平面上任意一點為原點,建立三維直角坐標系,其中,Z軸方向垂直於置物平面,載物台50採用可以帶動待測元件60在X軸、Y軸以及Z軸方向移動,且能夠帶動待測元件60在XY平面上旋轉的電動平移台。當然,在本發明其他實施例中,載物台50也可以採用具有六個自由度的電動平移台。In addition, it can be understood that when the component under test 60 is tested, the component under test 60 needs to be placed on the stage 50. As an optional implementation manner, as shown in FIG. 1, the defect detection device 1 provided in the embodiment of the present invention further includes a stage 50 for placing the component 60 to be tested. Further, in order to achieve line scanning of the component under test 60, as a scanning method, the stage 50 can be used not only to place the component under test 60, but also to drive the component under test 60 to move. Specifically, the stage 50 may be an electric translation stage or a manual translation stage. Of course, in order to control the scanning process more accurately, an electric translation stage is preferably used. In an embodiment of the present invention, if any point on the placing plane of the stage 50 is used as the origin, a three-dimensional rectangular coordinate system is established, wherein the Z axis direction is perpendicular to the placing plane, and the stage 50 can drive the component under test. 60 moves in the X-axis, Y-axis and Z-axis directions, and can drive the component under test 60 to rotate on the XY plane. Of course, in other embodiments of the present invention, the stage 50 may also be an electric translation stage with six degrees of freedom.
需要說明的是,在本發明的其他實施例中,載物台50也可以是另外配置的與本缺陷檢測設備1適配的載物台50,即不包括於本缺陷檢測設備1內。It should be noted that in other embodiments of the present invention, the stage 50 may also be a stage 50 that is additionally configured and adapted to the defect detection device 1, that is, it is not included in the defect detection device 1.
為了便於理解本技術方案,下面對本實施例提供的缺陷檢測設備11的工作過程進行簡單說明。In order to facilitate the understanding of the technical solution, the working process of the defect detection device 11 provided in this embodiment will be briefly described below.
第一光產生裝置產生的傳播方向一致且具有預設剪切量的第一偏振光和第二偏振光入射到待測元件60的待測表面。由待測元件60反射後形成第一回波光和第二回波光返回第一光產生裝置,通過光產生裝置合束後,進入偏振控制器30,經偏振控制器30進行偏振態處理後發生干涉、生成訊號光,被第一探測裝置40接收。The first polarized light and the second polarized light with the same propagation direction and a preset shear amount generated by the first light generating device are incident on the surface to be measured of the component to be measured 60. After being reflected by the component under test 60, the first echo light and the second echo light return to the first light generating device, and after being combined by the light generating device, they enter the polarization controller 30, and interfere with each other after being processed by the polarization controller 30. , Generate signal light, which is received by the first detection device 40.
本實施例中,要使得第一探測裝置40的第一探測區對待測元件60進行掃描,即使得待測元件60上同一預設檢測區域對應的訊號光分別被第一探測裝置40所包括的每個探測器接收,可以通過移動待測元件60實現。當然,在本發明的其他實施例中,也可以通過其他方式實現。In this embodiment, the first detection area of the first detection device 40 is required to scan the component under test 60, that is, the signal light corresponding to the same preset detection area on the component under test 60 is included in the first detection device 40. The reception of each detector can be realized by moving the component under test 60. Of course, in other embodiments of the present invention, it can also be implemented in other ways.
具體的,當待測元件60沿預設軌跡運動時,第一偏振光和第二偏振光沿預設軌跡對待測元件60進行掃描,待測元件60上的同一預設檢測區域對應的訊號光,隨著掃描時間的先後依次被每個探測器接收。本實施例中,預設軌跡可以根據待測元件60的檢測區域形狀設置,例如當檢測區域為圓環形時,預設軌跡可以為圓形軌跡,當檢測區域為方形時,預設軌跡可以是直線軌跡。Specifically, when the component under test 60 moves along the preset trajectory, the first polarized light and the second polarized light scan the component under test 60 along the preset trajectory, and the signal light corresponding to the same preset detection area on the component under test 60 , And are received by each detector in turn with the scanning time. In this embodiment, the preset trajectory can be set according to the shape of the detection area of the component under test 60. For example, when the detection area is circular, the preset trajectory can be a circular trajectory, and when the detection area is a square, the preset trajectory can be It is a straight trajectory.
此時,為了使得同一時刻第一探測裝置40所包括的不同探測器能夠更有效地檢測到待測表面相鄰區域(不同位置)對應的訊號光在對應偏振方向的強度分布,第一探測裝置40所包括的各探測器的工作面的排布方向,可以與第一偏振光和第二偏振光在待測元件60上的掃描方向平行,也即各探測器對應的第一探測單元區的排布方向與第一偏振光和第二偏振光在待測元件60上的掃描方向平行。At this time, in order to enable the different detectors included in the first detection device 40 at the same time to more effectively detect the intensity distribution of the signal light corresponding to the adjacent regions (different positions) of the surface to be measured in the corresponding polarization direction, the first detection device The arrangement direction of the working surface of each detector included in 40 may be parallel to the scanning direction of the first polarized light and the second polarized light on the component under test 60, that is, the first detection unit area corresponding to each detector The arrangement direction is parallel to the scanning direction of the first polarized light and the second polarized light on the component under test 60.
進一步地,由於檢測是掃描檢測,為了得到更好的檢測結果,需要設置掃描速度以及第一探測裝置40的採樣頻率。第一探測裝置40的相鄰兩次採樣的時間間隔內,第一探測裝置40的第一探測區掃描的距離,即第一偏振光和第二偏振光在待測元件60上形成的探測光斑相對於待測元件60的移動距離為掃描步長,則相鄰第一探測單元區中心之間的距離應當與該掃描步長適配。具體來講,相鄰第一探測單元區中心之間的距離等於該掃描步長的整數倍。Further, since the detection is a scanning detection, in order to obtain a better detection result, the scanning speed and the sampling frequency of the first detection device 40 need to be set. The scanning distance of the first detection area of the first detection device 40 within the time interval between two adjacent samplings of the first detection device 40, that is, the detection spot formed by the first polarized light and the second polarized light on the component under test 60 The moving distance relative to the component under test 60 is the scanning step length, and the distance between the centers of adjacent first detection unit regions should be adapted to the scanning step length. Specifically, the distance between the centers of adjacent first detection unit regions is equal to an integer multiple of the scanning step length.
為了進一步提高檢測效率,作為一種實施方式,相鄰第一探測單元區中心之間的距離等於該掃描步長。這樣就可以使得第一探測裝置40所包括的每個探測器隨著掃描時間的先後依次檢測到待測表面同一檢測區域對應的訊號光的強度分布,從而得到該檢測區域對應的訊號光在不同偏振方向的強度分布。掃描完成後,就可以得到待測元件60上每個檢測區域對應的訊號光在不同偏振方向的強度分布結果。In order to further improve the detection efficiency, as an implementation manner, the distance between the centers of adjacent first detection unit regions is equal to the scanning step length. In this way, each detector included in the first detection device 40 can sequentially detect the intensity distribution of the signal light corresponding to the same detection area on the surface to be measured with the sequence of scanning time, thereby obtaining that the signal light corresponding to the detection area is different. The intensity distribution in the polarization direction. After the scanning is completed, the intensity distribution results of the signal light corresponding to each detection area on the component under test 60 in different polarization directions can be obtained.
可以理解的是,在通過第一探測裝置40獲取到待測元件60的預設檢測區域對應的訊號光的第一光強分布資訊後,還需要進一步地對第一探測裝置40的檢測結果進行處理,才能得到待測元件60的缺陷分布資料。對於本發明實施例提供的缺陷檢測設備1,可以包括一資料處理裝置,用於對第一探測裝置40輸出的資料進行處理,得到待測元件60的缺陷分布資料,或者,也可以通過另外配置的資料處理裝置如電腦對第一探測裝置40輸出的資料進行處理。It is understandable that after the first light intensity distribution information of the signal light corresponding to the preset detection area of the component under test 60 is obtained by the first detection device 40, the detection result of the first detection device 40 needs to be further performed. Only by processing can the defect distribution data of the component under test 60 be obtained. For the defect detection equipment 1 provided by the embodiment of the present invention, it may include a data processing device for processing the data output by the first detection device 40 to obtain the defect distribution data of the component under test 60, or alternatively, it may be configured separately The data processing device, such as a computer, processes the data output by the first detection device 40.
當然,為了實現線上檢測,作為一種可選的實施例,本缺陷檢測設備1還可以包括第一處理裝置。第一處理裝置與第一探測裝置40電連接,以線上接收第一探測裝置40輸出的第一光強分布資訊。控制裝置用於根據訊號光的第一光強分布資訊獲取待測元件60的缺陷資訊。Of course, in order to implement online detection, as an optional embodiment, the defect detection device 1 may further include a first processing device. The first processing device is electrically connected to the first detection device 40 to receive the first light intensity distribution information output by the first detection device 40 on line. The control device is used to obtain defect information of the component under test 60 according to the first light intensity distribution information of the signal light.
具體的,第一處理裝置可以為電腦,或者也可以為包括DSP、ARM或FPGA等具有資料處理功能的晶片的資料處理電路模組。掃描檢測將得到第一探測裝置40輸出的探測資料流程,第一處理裝置可以通過預設的相位解調演算法對第一探測裝置40輸出的探測資料流程進行處理,得到待測元件60的每個採樣位置對應的訊號光的相位值。可以理解的是,第一探測裝置40接收到的訊號光相位將反應兩束相干光的相位差,由於這個相位差與兩束相干光對應的採樣位置間的高度差成正比,因此,可以根據訊號光的相位值得到相應採樣位置處的微小起伏,即得到相應採樣位置處的缺陷資訊。Specifically, the first processing device may be a computer, or may also be a data processing circuit module including a chip with data processing functions such as DSP, ARM, or FPGA. Scanning detection will obtain the detection data flow output by the first detection device 40, and the first processing device can process the detection data flow output by the first detection device 40 through a preset phase demodulation algorithm to obtain each of the components under test 60 The phase value of the signal light corresponding to each sampling position. It is understandable that the phase of the signal light received by the first detection device 40 will reflect the phase difference of the two coherent lights. Since this phase difference is proportional to the height difference between the sampling positions corresponding to the two coherent lights, it can be based on The phase value of the signal light obtains the slight fluctuation at the corresponding sampling position, that is, the defect information at the corresponding sampling position is obtained.
由於入射到待測元件60的第一偏振光和第二偏振光的橫向剪切量Δa能夠小於一般光學系統解析度極限,對應的兩個橫向測量位置非常近,因此本缺陷檢測設備1可以在縱向上(垂直於被測表面的方向上)達到較高的檢測精度。Since the transverse shear amount Δa of the first polarized light and the second polarized light incident on the component under test 60 can be less than the resolution limit of a general optical system, and the corresponding two transverse measurement positions are very close, the defect detection device 1 can Longitudinal (in the direction perpendicular to the measured surface) to achieve high detection accuracy.
下面將同樣以晶圓為例說明如何對這些資料進行處理,得到晶圓表面缺陷分布。可以理解的是,第一探測裝置40輸出的探測資料流程中包含了晶圓上每個採樣位置對應的訊號光在不同偏振方向的強度分布。根據每個採樣位置對應的訊號光在不同偏振方向的強度分布,計算每個採樣位置對應的訊號光的相位值,從而得到晶圓表面所有採樣位置對應的訊號光的相位分布,進而根據該相位分布計算各採樣位置處的缺陷資訊,得到晶圓表面的缺陷分布資料。The following will also take the wafer as an example to illustrate how to process these data to obtain the surface defect distribution of the wafer. It can be understood that the detection data flow output by the first detection device 40 includes the intensity distribution of the signal light corresponding to each sampling position on the wafer in different polarization directions. According to the intensity distribution of the signal light corresponding to each sampling position in different polarization directions, the phase value of the signal light corresponding to each sampling position is calculated, so as to obtain the phase distribution of the signal light corresponding to all sampling positions on the wafer surface, and then according to the phase The distribution calculates the defect information at each sampling position, and obtains the defect distribution data on the wafer surface.
例如,當第一探測裝置40包括四個偏振線探測器,偏振探測方向分別為0度、45度、90度和135度時,取偏振線探測器接收到的訊號光強為
Figure 02_image001
,其中,i=1,2,3,4,分別對應在0度、45度、90度、135度偏振方向的光強,r為線探測器對應圖元點資訊,t是採樣時間。結合具體掃描軌跡可以將(r,t)轉換為晶圓上位置分布。假設目標訊號對應的訊號光相位用
Figure 02_image003
表示,則理論上訊號光相位滿足以下公式(1):
Figure 02_image005
(1)
For example, when the first detection device 40 includes four polarization line detectors, and the polarization detection directions are 0 degrees, 45 degrees, 90 degrees, and 135 degrees, the intensity of the signal received by the polarization line detector is taken as
Figure 02_image001
, Where i=1, 2, 3, 4, corresponding to the light intensity in the polarization direction of 0 degree, 45 degree, 90 degree, and 135 degree respectively, r is the pixel point information corresponding to the line detector, and t is the sampling time. Combining the specific scanning trajectory, (r, t) can be converted into position distribution on the wafer. Assuming that the signal light phase corresponding to the target signal is used
Figure 02_image003
Means that the optical phase of the signal theoretically satisfies the following formula (1):
Figure 02_image005
(1)
根據上述公式即可以得到第一探測裝置40所檢測到的訊號光的相位分布。According to the above formula, the phase distribution of the signal light detected by the first detection device 40 can be obtained.
然而,發明人在通過本檢測設備實際對晶圓進行檢測的過程中發現,儘管理論上不存在缺陷時晶圓表面非常平整,訊號光相位等於0,但是有許多因素將引起雜訊,如:光學系統相位誤差、探測器前起偏部分具有一定消偏比、光源頻寬的影響、掃描過程晶圓表面平面度改變等,這些因素將使得所得到的訊號光產生一個隨位置變化誤差,直接計算得到的相位零點不再位於相位零值,同時有不反應晶圓表面高度變化的慢變包絡。例如,圖4示出了一個根據實際檢測資料計算得到的相位隨時間變化示意圖,由於晶圓的檢測區域內有一個凸起缺陷,相位呈現出向上凸起和向下凹陷,分別對應缺陷的上升及下降沿,然而在平整位置,相位依舊存在波動。在平整位置存在的這些波動即為相位雜訊。However, the inventor discovered during the actual inspection of the wafer through the inspection equipment that although the wafer surface is theoretically flat when there are no defects, and the signal light phase is equal to 0, there are many factors that will cause noise, such as: The phase error of the optical system, the front polarization part of the detector has a certain depolarization ratio, the influence of the light source bandwidth, the flatness of the wafer surface during the scanning process, etc., these factors will cause the obtained signal light to produce a position-dependent error, directly The calculated phase zero point is no longer at the phase zero value, and has a slowly varying envelope that does not reflect the height change of the wafer surface. For example, Figure 4 shows a schematic diagram of the phase change over time calculated based on the actual inspection data. Since there is a convex defect in the inspection area of the wafer, the phase is convex upward and concave downward, corresponding to the rise of the defect. And the falling edge, but in the flat position, the phase still fluctuates. These fluctuations in the flat position are the phase noise.
因此,在實際檢測中,訊號光相位
Figure 02_image007
應滿足以下公式(2):
Figure 02_image009
(2)
Therefore, in actual detection, the signal light phase
Figure 02_image007
The following formula (2) should be satisfied:
Figure 02_image009
(2)
其中,
Figure 02_image011
表示相位雜訊。
among them,
Figure 02_image011
Indicates phase noise.
基於上述分析,在本發明一實施例中,需要對第一探測裝置40輸出的第一光強分布資訊進行雜訊預處理,以消除上述雜訊。此時,第一處理裝置包括:訊號解調模組、雜訊獲取模組和目標資訊獲取模組。其中,訊號解調模組,用於根據訊號光的第一光強分布資訊獲取訊號光的初始資訊;雜訊獲取模組,用於對訊號光的第一光強分布資訊進行低通濾波處理,獲取雜訊資訊;目標資訊獲取模組,用於根據初始資訊以及雜訊資訊獲取待測元件60的缺陷資訊。Based on the above analysis, in an embodiment of the present invention, it is necessary to perform noise preprocessing on the first light intensity distribution information output by the first detection device 40 to eliminate the above noise. At this time, the first processing device includes: a signal demodulation module, a noise acquisition module, and a target information acquisition module. Among them, the signal demodulation module is used to obtain the initial information of the signal light according to the first light intensity distribution information of the signal light; the noise acquisition module is used to perform low-pass filtering processing on the first light intensity distribution information of the signal light , Obtain noise information; the target information obtaining module is used to obtain defect information of the component under test 60 according to the initial information and the noise information.
其中,上述初始資訊包括訊號光的初始相位資訊。具體的,以第一探測裝置40包括四個偏振線探測器,且偏振探測方向分別為0度、45度、90度和135度的場景為例,可以根據上述公式(1)計算訊號光的初始相位資訊。Wherein, the above-mentioned initial information includes initial phase information of the signal light. Specifically, taking a scene where the first detection device 40 includes four polarization line detectors and the polarization detection directions are 0 degrees, 45 degrees, 90 degrees, and 135 degrees, as an example, the signal light can be calculated according to the above formula (1). Initial phase information.
上述雜訊資訊包括雜訊相位資訊。具體可以通過對訊號光的第一光強分布資訊進行低通濾波處理後,進行相位解調得到該雜訊相位資訊。The aforementioned noise information includes noise phase information. Specifically, the noise phase information can be obtained by performing low-pass filtering on the first light intensity distribution information of the signal light, and then performing phase demodulation.
具體來講,上述目標資訊獲取模組包括:目標相位獲取子模組和缺陷資訊獲取子模組。其中,目標相位獲取子模組,用於對所述初始相位資訊和所述雜訊相位資訊進行差值處理,獲取目標相位資訊。也就是說,如圖5所示,用所得到的初始相位資訊減去雜訊相位資訊即上述公式(2)中的
Figure 02_image011
,即可以得到目標相位資訊
Figure 02_image007
。對比圖4和圖6可以看出,通過上述預處理,能夠有效地去除雜訊對所得到的相位分布結果的影響,有利於提高檢測結果的準確性。進一步的,就可以根據該相位分布計算各採樣位置處的缺陷資訊,得到晶圓表面的缺陷分布資料。
Specifically, the aforementioned target information acquisition module includes: a target phase acquisition sub-module and a defect information acquisition sub-module. Wherein, the target phase obtaining sub-module is used to perform difference processing on the initial phase information and the noise phase information to obtain target phase information. That is to say, as shown in Figure 5, subtract the noise phase information from the obtained initial phase information, which is the formula in the above formula (2)
Figure 02_image011
, You can get the target phase information
Figure 02_image007
. Comparing FIG. 4 and FIG. 6, it can be seen that through the above preprocessing, the influence of noise on the obtained phase distribution result can be effectively removed, which is beneficial to improve the accuracy of the detection result. Further, the defect information at each sampling position can be calculated according to the phase distribution, and the defect distribution data on the surface of the wafer can be obtained.
缺陷資訊獲取子模組,用於根據所述目標相位資訊獲取所述待測元件60的缺陷資訊。作為一種可選方式,可以根據訊號光的目標相位資訊計算待測元件60表面相應位置處的高度差,從而得出待測元件60的缺陷資訊。作為另一種可選方式,目標資訊獲取模組還可以包括:缺陷標準庫,缺陷標準庫包括多個預設相位資訊和相應的預設缺陷資訊,用於確定相位資訊與缺陷資訊之間的對應關係。此時,上述缺陷資訊獲取子模組具體用於根據所述目標相位資訊在所述缺陷標準庫中進行查找,獲取相應的預設缺陷資訊,從而得到所述待測元件60的缺陷資訊。也就是說,將基於目標相位資訊,在缺陷標準庫中查找到的缺陷資訊作為待測元件60的缺陷資訊。The defect information obtaining sub-module is used to obtain defect information of the component under test 60 according to the target phase information. As an optional method, the height difference at the corresponding position on the surface of the component under test 60 can be calculated according to the target phase information of the signal light, so as to obtain the defect information of the component under test 60. As another optional method, the target information acquisition module may also include: a defect standard library, which includes a plurality of preset phase information and corresponding preset defect information, and is used to determine the correspondence between the phase information and the defect information relationship. At this time, the above-mentioned defect information acquisition sub-module is specifically configured to search in the defect standard library according to the target phase information, and obtain corresponding preset defect information, so as to obtain the defect information of the component under test 60. In other words, the defect information found in the defect standard library based on the target phase information is used as the defect information of the component under test 60.
例如,可以預先採用定標的方法得到待測元件60對應的訊號光相位與表面高度的對應關係。具體過程可以為:製作一系列高度標準片(如10奈米、20奈米、30奈米等),直接測量得到它們對應的相位分布,根據測量資料得到相位-高度對應關係曲線。在實際測量時根據得到的目標相位值查找相應的高度資訊。這樣有利於更加精確地提到待測表面的高度分布,並有利於結合簡化缺陷資訊的計算過程,提高檢測效率。For example, a calibration method can be used in advance to obtain the corresponding relationship between the signal light phase and the surface height of the component under test 60. The specific process can be: making a series of height standard films (such as 10nm, 20nm, 30nm, etc.), directly measuring their corresponding phase distribution, and obtaining the phase-height correspondence curve based on the measurement data. In the actual measurement, find the corresponding height information according to the obtained target phase value. This is beneficial to more accurately mention the height distribution of the surface to be tested, and is conducive to simplifying the calculation process of defect information and improving the inspection efficiency.
以上第一處理裝置中包括的各模組可以是由軟體代碼實現,此時,上述的各模組可存儲於第一處理裝置的記憶體內。或者,以上第一處理裝置中包括的各模組同樣可以由硬體電路例如積體電路晶片實現。The modules included in the above first processing device may be implemented by software code. In this case, the above modules may be stored in the memory of the first processing device. Alternatively, each module included in the above first processing device can also be implemented by a hardware circuit such as an integrated circuit chip.
作為一種可選的實施例,如圖7所示,本實施例提供的缺陷檢測設備2除了包括上述光產生調製裝置和第一探測裝置40以外,還包括:第二探測裝置72。第二探測裝置72,用於收集所述待測元件60表面的散射光,並獲取所述散射光的第二光強分布資訊。從而在上述基於第一探測裝置40的檢測通道即差分干涉法檢測通道的基礎上,增加了散射光檢測通道,從而實現明、暗場結合檢測。As an optional embodiment, as shown in FIG. 7, the defect detection device 2 provided in this embodiment includes a second detection device 72 in addition to the above-mentioned light generation and modulation device and the first detection device 40. The second detection device 72 is used to collect scattered light on the surface of the component under test 60 and obtain the second light intensity distribution information of the scattered light. Therefore, on the basis of the detection channel based on the first detection device 40, that is, the detection channel of the differential interferometry, the detection channel of scattered light is added, thereby realizing the combined detection of bright and dark fields.
光散射法缺陷檢測原理為:鐳射斜入射照射至待測元件60表面某點位置,當待測元件60表面不存在缺陷時,待測元件60表現出類似鏡面效果,入射光將以相同的角度從另一側反射出去;當待測元件60表面存在缺陷時,入射光將與缺陷發生散射作用,產生的散射光朝待測元件60表面上方各方向傳輸,散射光強度與缺陷尺寸成正比關係。因此,可以通過探測待測元件60表面上方的散射光,得到待測元件60表面的缺陷分布及缺陷尺寸資訊。The principle of defect detection by light scattering method is: the laser is irradiated obliquely to a certain point on the surface of the component under test 60. When there is no defect on the surface of the component under test 60, the component under test 60 exhibits a mirror-like effect, and the incident light will be at the same angle Reflected from the other side; when there is a defect on the surface of the component under test 60, the incident light will scatter with the defect, and the scattered light generated will be transmitted in all directions above the surface of the component under test 60. The intensity of the scattered light is proportional to the size of the defect. . Therefore, by detecting the scattered light above the surface of the device under test 60, the defect distribution and defect size information on the surface of the device under test 60 can be obtained.
本實施例提供的缺陷檢測設備2還包括第二光產生裝置71。第二光產生裝置71用於產生第二探測光,並使第二探測光經所述待測元件60表面散射,形成所述散射光。具體來講,第二光產生裝置71產生的第二探測光以預設角度斜入射到待測元件60表面的預設檢測區域,當該預設檢測區域存在缺陷時,入射的第二探測光在缺陷處發生散射,形成散射光。The defect detection equipment 2 provided in this embodiment further includes a second light generating device 71. The second light generating device 71 is used to generate the second probe light and cause the second probe light to be scattered by the surface of the component under test 60 to form the scattered light. Specifically, the second detection light generated by the second light generating device 71 obliquely enters the predetermined detection area on the surface of the component under test 60 at a predetermined angle. When the predetermined detection area has a defect, the incident second detection light Scattering occurs at the defect, forming scattered light.
本實施例中,所述缺陷檢測設備2還包括:反射杯(圖中未示出),用於收集待測表面的散射光。所述第二光產生裝置71產生的第二探測光在待測元件60上的光斑為點光斑。所述第二探測裝置72為光電二極體或光電倍增管。In this embodiment, the defect detection device 2 further includes a reflection cup (not shown in the figure) for collecting scattered light from the surface to be tested. The light spot of the second probe light generated by the second light generating device 71 on the component under test 60 is a spot light spot. The second detection device 72 is a photodiode or a photomultiplier tube.
由於散射光的出射方向是任意的,第二探測裝置72的位置可以根據需要設置。作為一種可選的方式,散射光探測通道可以與訊號光探測通道共光路。例如,如圖7所示,第二光產生裝置71發出的第二探測光從物鏡下方以預設入射角斜入射至待測元件60表面。其中,預設角度可以根據實際需要設置如預設入射角可以為72°。Since the emission direction of the scattered light is arbitrary, the position of the second detection device 72 can be set as required. As an optional way, the scattered light detection channel can share the optical path with the signal light detection channel. For example, as shown in FIG. 7, the second detection light emitted by the second light generating device 71 obliquely enters the surface of the component under test 60 at a predetermined incident angle from below the objective lens. Among them, the preset angle can be set according to actual needs, for example, the preset incident angle can be 72°.
需要說明的是,第二探測光在待測元件60上的光斑形狀和尺寸可以根據需要調整,例如,可以通過在第二光產生裝置71的出光路徑上設置擴束整形裝置74來調整。本實施例中,可以將第二探測光在待測元件60上的光斑調整為點光斑,以便於利用反光杯對散射光進行收集,且能夠減小相鄰區域散射光的幹擾。為了與訊號光相區別,第二光產生裝置71發出的第二探測光的波長可以與第一光產生裝置發出的第一探測光的波長不同。可以理解的是,第一探測光、第一偏振光、第二偏振光以及訊號光的波長是一致的。此外,為了減小雜散光對第一回波光和第二回波光的幹擾,因此,還需要在光接收通道上,增設第二分束器73將物鏡203接收到的光分為兩部分,分別用於兩通道訊號接收,如圖7所示。同時,在第一探測裝置40前增設第一濾光片75,以濾除該接收通道上的散射光。在第二探測裝置72前增設第二濾光片76,以濾除該接收通道上的幹擾光,散射光在該通道上透過第二濾光片76、經會聚透鏡77彙聚到第二探測裝置72。It should be noted that the shape and size of the spot of the second probe light on the component under test 60 can be adjusted as required. For example, the beam expansion shaping device 74 can be arranged on the light exit path of the second light generating device 71. In this embodiment, the light spot of the second probe light on the component under test 60 can be adjusted to a point light spot, so that the scattered light can be collected by the reflector, and the interference of the scattered light in the adjacent area can be reduced. In order to be distinguished from the signal light, the wavelength of the second detection light emitted by the second light generating device 71 may be different from the wavelength of the first detection light emitted by the first light generating device. It can be understood that the wavelengths of the first probe light, the first polarized light, the second polarized light, and the signal light are the same. In addition, in order to reduce the interference of stray light on the first echo light and the second echo light, it is also necessary to add a second beam splitter 73 on the light receiving channel to divide the light received by the objective lens 203 into two parts, respectively Used for two-channel signal reception, as shown in Figure 7. At the same time, a first filter 75 is added in front of the first detection device 40 to filter out the scattered light on the receiving channel. A second filter 76 is added in front of the second detection device 72 to filter out the interference light on the receiving channel. The scattered light passes through the second filter 76 on the channel and is condensed to the second detection device through the condenser lens 77 72.
需要說明的是,第二分束器73的位置可以根據需要設置,例如,可以設置在第一分束器201與偏振控制器30之間的光傳播路徑上,或者,也可以設置在物鏡203與雙折射晶體202之間的光傳播路徑上。It should be noted that the position of the second beam splitter 73 can be set as required. For example, it can be set on the light propagation path between the first beam splitter 201 and the polarization controller 30, or it can be set on the objective lens 203. And the birefringent crystal 202 on the light propagation path.
本實施例中,分別通過第一光產生裝置和第二光產生裝置71在待測元件60表面形成探測光斑,相應地,分別由第一探測裝置40對待測元件60表面反射形成的訊號光進行探測,由第二探測裝置72對待測元件60表面散射的散射光進行探測。也就是說,分別控制差分干涉法檢測通道以及散射光檢測通道對待測元件60進行檢測。In this embodiment, the first light generating device and the second light generating device 71 respectively form detection spots on the surface of the component under test 60. Correspondingly, the signal light formed by the reflection of the surface of the component under test 60 is performed by the first detection device 40 respectively. For detection, the second detection device 72 detects the scattered light scattered on the surface of the test element 60. In other words, the differential interferometry detection channel and the scattered light detection channel are respectively controlled to detect the component 60 under test.
具體來講,基於上述對第一探測區的定義,第二探測裝置72也包括第二探測區。第二探測裝置72用於獲取第二探測區內的待測元件60表面散射的散射光。Specifically, based on the above definition of the first detection zone, the second detection device 72 also includes the second detection zone. The second detection device 72 is used to obtain the scattered light scattered on the surface of the component under test 60 in the second detection area.
控制散射光檢測通道對待測元件60進行檢測的方式可以為:將待測元件60劃分為多個檢測區域,依次使得控制第二探測光在待測元件60表面上形成的光斑以及第二探測區覆蓋每個檢測區域,從而依次獲取到待測元件60表面每個檢測區域形成的散射光。The method of controlling the scattered light detection channel to detect the component under test 60 may be: dividing the component under test 60 into a plurality of detection areas, so as to control the spot formed by the second probe light on the surface of the component under test 60 and the second detection area in turn. Each detection area is covered, so that the scattered light formed by each detection area on the surface of the component under test 60 can be obtained in turn.
在使第二探測區沿待測表面直徑掃描的同時,所述第二探測區還沿所述待測表面直徑方向移動。While scanning the second detection area along the diameter of the surface to be measured, the second detection area also moves along the diameter direction of the surface to be measured.
另外,由於增設了散射光檢測通道,不同於上述第一處理裝置,本實施例還包括第二處理裝置。上述第一探測裝置40和第二探測裝置72均與第二處理裝置電連接。第二處理裝置,用於根據由第一探測裝置40獲取到的訊號光的第一光強分布資訊得到所述待測元件60的第一缺陷資訊,根據第二探測裝置72獲取到的散射光的第二光強分布資訊得到待測元件60的第二缺陷資訊,並基於所述第一缺陷資訊和所述第二缺陷資訊得到所述待測元件60的目標缺陷資訊。具體的,第二處理裝置也可以為電腦,或者也可以為包括DSP、ARM或FPGA等具有資料處理功能的晶片的資料處理電路模組。In addition, because the scattered light detection channel is added, unlike the first processing device described above, this embodiment also includes a second processing device. The above-mentioned first detection device 40 and second detection device 72 are both electrically connected to the second processing device. The second processing device is used to obtain the first defect information of the component under test 60 according to the first light intensity distribution information of the signal light obtained by the first detecting device 40, and to obtain the first defect information of the component under test 60 according to the scattered light obtained by the second detecting device 72 The second light intensity distribution information is obtained to obtain the second defect information of the device under test 60, and the target defect information of the device under test 60 is obtained based on the first defect information and the second defect information. Specifically, the second processing device may also be a computer, or may also be a data processing circuit module including a chip with data processing functions such as DSP, ARM, or FPGA.
其中,根據第一光強分布資訊得到待測元件60的第一缺陷資訊的過程可以參照上述第一處理裝置的處理過程,此處不再贅述。The process of obtaining the first defect information of the device under test 60 according to the first light intensity distribution information can refer to the process of the above-mentioned first processing device, which will not be repeated here.
第一缺陷資訊包括第一缺陷位置資訊及第一缺陷尺寸資訊,第二缺陷資訊包括第二缺陷位置資訊及第二缺陷尺寸資訊。基於第一缺陷資訊和所述第二缺陷資訊得到所述待測元件60的目標缺陷資訊的具體過程可以為:對第一缺陷資訊和第二缺陷資訊進行缺陷累加,並進行共有缺陷合併判斷,得到待測元件60的缺陷資訊。由於缺陷檢測時可能存在位置誤差,導致同一缺陷不同通道得到的位置稍有差別,因此在進行缺陷合併時需要進行缺陷判斷。具體缺陷判斷方法如下:首先遍歷單通道得到的所有缺陷,取出單通道(如光散射法通道)得到的任意一個缺陷作為當前缺陷;依次計算當前缺陷與另一個通道(如差分干涉法通道)得到的每個缺陷之間的距離;判斷該距離是否小於預設閾值,若該距離小於預設閾值,則認為該距離對應兩個缺陷為同一缺陷,進行合併處理即將這兩個缺陷合併為一個。將該單通道得到的下一缺陷作為當前缺陷,重複上述距離計算以及距離判斷過程,直至完成該單通道得到的所有缺陷的判斷。The first defect information includes first defect location information and first defect size information, and the second defect information includes second defect location information and second defect size information. The specific process of obtaining the target defect information of the component under test 60 based on the first defect information and the second defect information may be: performing defect accumulation on the first defect information and the second defect information, and performing a common defect merger judgment. Obtain defect information of the component 60 to be tested. Since there may be position errors during defect detection, the positions obtained by different channels of the same defect are slightly different, so defect judgment is required when performing defect merging. The specific defect judgment method is as follows: first traverse all the defects obtained in a single channel, take out any defect obtained in a single channel (such as light scattering method channel) as the current defect; sequentially calculate the current defect and another channel (such as a differential interferometry channel) to obtain The distance between each defect; judge whether the distance is less than the preset threshold, if the distance is less than the preset threshold, the distance corresponding to the two defects is considered to be the same defect, and the merge process is to merge the two defects into one. The next defect obtained by the single channel is regarded as the current defect, and the above distance calculation and distance judgment process are repeated until the judgment of all defects obtained by the single channel is completed.
其中,預設閾值的選取可以通過多次實驗測得。例如,可以選取不同閾值進行合併判斷,取合併結果與實際最相近時的值作為預設閾值。Among them, the selection of the preset threshold can be measured through multiple experiments. For example, different thresholds can be selected for merging judgment, and the value when the merging result is closest to the actual situation is taken as the preset threshold.
綜上所述,本發明實施例提供的缺陷檢測設備,基於第一探測裝置40實現訊號光的偏振態判斷,並可以通過線掃描的方式進行元件缺陷檢測,得到訊號光的相位分布,根據訊號光的相位分布,得到兩束相干光的光程差,從而得到待測元件60表面的微小起伏,實現了待測元件60在縱向(垂直於被測表面方向)上缺陷的高精度檢測,如對凹坑類缺陷的高精度檢測,且可靠性好,穩定性高,檢測速度快。此外,根據晶圓檢測中雜訊規律提出相位雜訊濾除辦法,提高了檢測結果的信噪比,即進一步提高了缺陷檢測精度。In summary, the defect detection equipment provided by the embodiment of the present invention realizes the polarization state judgment of the signal light based on the first detection device 40, and can perform component defect detection by means of line scanning to obtain the phase distribution of the signal light. The phase distribution of the light, the optical path difference of the two coherent lights is obtained, so as to obtain the small undulations on the surface of the component under test 60, which realizes the high-precision detection of the defects of the component under test 60 in the longitudinal direction (the direction perpendicular to the surface under test), such as High-precision detection of pit defects, with good reliability, high stability and fast detection speed. In addition, the phase noise filtering method is proposed according to the noise rule in wafer inspection, which improves the signal-to-noise ratio of the inspection result, that is, further improves the defect detection accuracy.
進一步,通過在差分干涉法檢測通道的基礎上,增設散射光檢測通道,實現明、暗場結合檢測,不僅能提高在縱向(垂直於被測表面方向)上的缺陷檢測精度,還能夠提高橫向解析度。Furthermore, by adding a scattered light detection channel on the basis of the differential interferometry detection channel, the combined detection of bright and dark fields can be realized, which can not only improve the detection accuracy of defects in the longitudinal direction (perpendicular to the surface to be tested), but also improve the transverse direction. Resolution.
另外,本發明實施例還提供了一種缺陷檢測方法,可以應用於上述第一實施例提供的缺陷檢測設備。當然,除了上述缺陷檢測設備以外,也可以應用於其他適用的缺陷檢測設備。如圖8所示,所述方法包括:In addition, the embodiment of the present invention also provides a defect detection method, which can be applied to the defect detection device provided in the above-mentioned first embodiment. Of course, in addition to the above-mentioned defect detection equipment, it can also be applied to other applicable defect detection equipment. As shown in Figure 8, the method includes:
步驟S801,通過光產生調製裝置產生第一偏振光和第二偏振光,並使所述第一偏振光經待測元件60的待測表面反射形成第一回波光,所述第二偏振光經所述待測表面反射形成第二回波光,其中,所述第一偏振光和第二偏振光中心之間具有預設剪切量;In step S801, the first polarized light and the second polarized light are generated by the light generating and modulating device, and the first polarized light is reflected by the surface to be measured of the component under test 60 to form first echo light, and the second polarized light is passed through The surface to be tested reflects to form a second echo light, wherein there is a preset shear amount between the centers of the first polarized light and the second polarized light;
步驟S802,通過所述光產生調製裝置使所述第一回波光和第二回波光發生干涉,形成訊號光;Step S802, causing the first echo light and the second echo light to interfere with each other through the light generating and modulating device to form signal light;
步驟S803,通過第一探測裝置40獲取所述訊號光沿多個不同偏振方向的光強資訊,或者獲取所述訊號光總的光強資訊以及至少沿一個偏振方向的光強資訊。Step S803: Obtain the light intensity information of the signal light along a plurality of different polarization directions through the first detection device 40, or obtain the total light intensity information of the signal light and the light intensity information along at least one polarization direction.
需要說明的是,當第一探測裝置40包括兩個及以上偏振探測器,且不同偏振探測器的偏振探測方向不同時,則可以獲取到訊號光沿多個不同偏振方向的光強資訊。當第一探測裝置40包括無偏振探測器以及至少一個偏振探測器時,則可以獲取到訊號光總的光強資訊以及至少沿一個偏振方向的光強資訊。其中,總的光強資訊是指由無偏振探測器獲取到的訊號光的光強資訊。本實施例中,將訊號光沿多個不同偏振方向的光強資訊,或者是,訊號光總的光強資訊以及至少沿一個偏振方向的光強資訊作為訊號光的第一光強分布資訊。It should be noted that when the first detection device 40 includes two or more polarization detectors, and the polarization detection directions of different polarization detectors are different, the light intensity information of the signal light along multiple different polarization directions can be obtained. When the first detection device 40 includes a non-polarization detector and at least one polarization detector, the total light intensity information of the signal light and the light intensity information along at least one polarization direction can be obtained. Among them, the total light intensity information refers to the light intensity information of the signal light obtained by the non-polarization detector. In this embodiment, the light intensity information of the signal light along a plurality of different polarization directions, or the total light intensity information of the signal light and the light intensity information along at least one polarization direction are used as the first light intensity distribution information of the signal light.
具體的,由於第一探測裝置40包括第一探測區,且第一探測區包括多個第一探測單元區,要獲取待測元件60表面某一檢測區域對應的訊號光的第一光強分布資訊,需要使得第一探測裝置40所包括的每個探測器均接收到該檢測區域對應的訊號光,需要使得第一探測區在待測元件60上掃描,使得每個第一探測單元區隨著掃描時間的先後依次覆蓋該檢測區域。Specifically, since the first detection device 40 includes a first detection area, and the first detection area includes a plurality of first detection unit areas, the first light intensity distribution of the signal light corresponding to a certain detection area on the surface of the component 60 to be tested must be acquired. Information, each detector included in the first detection device 40 needs to receive the signal light corresponding to the detection area, and the first detection area needs to be scanned on the component under test 60 so that each first detection unit area follows Cover the detection area in sequence with the scan time.
作為一種可選方式,所述方法還包括:控制所述第一偏振光和第二偏振光在所述待測表面掃描,並重複上述步驟S802和步驟S803。也就是說,在第一偏振光和第二偏振光在待測表面形成的光斑對待測表面進行掃描的過程中,各掃描區域將先後反射第一回波光和第二回波光形成訊號光,同時,各掃描區域所對應的訊號光將隨著掃描時間的先後依次被第一探測裝置40接收,得到第一光強分布資訊。As an optional manner, the method further includes: controlling the first polarized light and the second polarized light to scan on the surface to be measured, and repeating the above steps S802 and S803. That is to say, in the process of scanning the surface to be measured by the spot formed by the first polarized light and the second polarized light on the surface to be measured, each scanning area will reflect the first echo light and the second echo light successively to form signal light, and at the same time , The signal light corresponding to each scanning area will be sequentially received by the first detection device 40 with the scanning time sequence to obtain the first light intensity distribution information.
具體來講,可以保持第一偏振光和第二偏振光的入射位置以及第一探測裝置40的位置不變,通過電動載物台50或其他執行機構控制待測元件60沿預設軌跡運動,從而使得第一偏振光和第二偏振光在待測元件60表面形成的探測光斑對待測元件60進行掃描,同時使得第一探測裝置40的第一探測區隨著探測光斑對待測元件60進行掃描。Specifically, the incident position of the first polarized light and the second polarized light and the position of the first detection device 40 can be kept unchanged, and the component under test 60 can be controlled to move along a preset trajectory through the electric stage 50 or other actuators. Thus, the detection spot formed by the first polarized light and the second polarized light on the surface of the component under test 60 scans the component under test 60, and at the same time, the first detection area of the first detection device 40 scans the component under test 60 with the detection spot. .
作為一種可選的實施方式,所述第一偏振光和第二偏振光在所述待測表面的掃描方向與所述多個第一探測單元區的排列方向相同。As an optional implementation manner, the scanning direction of the first polarized light and the second polarized light on the surface to be measured is the same as the arrangement direction of the plurality of first detection unit regions.
作為一種可選的實施方式,獲取所述第一光強資訊的步驟包括:通過所述第一探測裝置40對所述訊號光的光強進行採樣,相鄰兩次採樣的時間間隔內,所述第一探測區掃描的距離為掃描步長,相鄰所述第一探測單元區中心之間的距離等於所述掃描步長的整數倍。As an optional implementation manner, the step of acquiring the first light intensity information includes: sampling the light intensity of the signal light by the first detection device 40, and within the time interval of two adjacent samples, so The scanning distance of the first detection area is a scanning step length, and the distance between the centers of adjacent first detection unit areas is equal to an integer multiple of the scanning step length.
作為一種可選的實施方式,相鄰所述第一探測單元區中心之間的距離等於所述掃描步長。As an optional implementation manner, the distance between the centers of adjacent first detection unit regions is equal to the scan step length.
作為一種可選的實施方式,控制所述第一偏振光和第二偏振光在待測表面掃描的步驟包括:控制所述待測元件60的待測表面沿與預設掃描方向相反的方向移動。也就是說,上述預設軌跡與掃描方向相反。As an optional implementation, the step of controlling the scanning of the first polarized light and the second polarized light on the surface to be measured includes: controlling the surface to be measured of the component to be measured 60 to move in a direction opposite to the preset scanning direction . In other words, the above-mentioned preset trajectory is opposite to the scanning direction.
作為一種可選的實施方式,當光產生調製裝置包括第一光源101和擴束整形裝置102時,所述產生第一偏振光和第二偏振光的步驟可以包括:通過所述第一光源101產生第一探測光,以基於所述第一探測光形成第一偏振光和第二偏振光;通過所述擴束整形裝置102調整所述第一偏振光和第二偏振光在待測元件60的待測表面所形成的光斑形狀和尺寸,使在沿所述第一探測區對所述待測元件60表面的掃描方向上,所述探測光斑的尺寸大於或等於所述第一探測區的尺寸。As an optional implementation manner, when the light generating and modulating device includes the first light source 101 and the beam expanding and shaping device 102, the step of generating the first polarized light and the second polarized light may include: passing the first light source 101 The first probe light is generated to form the first polarized light and the second polarized light based on the first probe light; the beam expander 102 adjusts the first polarized light and the second polarized light in the device under test 60 The shape and size of the spot formed by the surface to be measured are such that in the scanning direction of the surface of the element to be measured 60 along the first detection area, the size of the detection spot is greater than or equal to that of the first detection area. size.
作為一種可選的實施方式,所述控制所述待測元件60的待測表面沿與所述掃描方向相反的方向移動的步驟包括: 控制所述待測元件60繞垂直於所述待測表面的轉軸旋轉; 所述控制所述第一偏振光和第二偏振光在所述待測元件60表面掃描的步驟還包括:當所述待測表面繞所述轉軸旋轉一周之後或者在所述待測表面繞所述轉軸旋轉的過程中,控制所述第一偏振光和第二偏振光在所述待測表面形成的光斑沿所述待測表面的直徑方向移動。As an optional implementation manner, the step of controlling the surface to be tested of the component to be tested 60 to move in a direction opposite to the scanning direction includes: Controlling the component under test 60 to rotate around a rotation axis perpendicular to the surface under test; The step of controlling the scanning of the first polarized light and the second polarized light on the surface of the component under test 60 further includes: when the surface to be tested rotates one circle around the axis of rotation, or after the surface to be tested rotates around the surface During the rotation of the shaft, the light spot formed by the first polarized light and the second polarized light on the surface to be measured is controlled to move along the diameter direction of the surface to be measured.
本實施例中,當所述待測表面繞所述轉軸旋轉一周之後,控制所述第一偏振光和第二偏振光在所述待測表面形成的光斑沿所述待測表面的直徑方向移動。這樣能夠使獲得的訊號光較穩定,從而能夠增加檢測精度。In this embodiment, after the surface to be measured rotates once around the axis of rotation, the light spot formed by the first polarized light and the second polarized light on the surface to be measured is controlled to move along the diameter direction of the surface to be measured . This can make the obtained signal light more stable, which can increase the detection accuracy.
在其他實施例中,在所述待測表面繞所述轉軸旋轉的過程中,控制所述第一偏振光和第二偏振光在所述待測表面形成的光斑沿所述待測表面的直徑方向移動,能夠增加檢測效率。In other embodiments, when the surface to be measured rotates around the axis of rotation, the diameter of the spot formed by the first polarized light and the second polarized light on the surface to be measured is controlled along the surface to be measured Directional movement can increase the detection efficiency.
實際檢測時,為了便於掃描控制,可以將待測元件60置於載物台50上,通超載物台50帶動待測元件60沿預設軌跡運動。例如,在一種具體應用場景中,以晶圓為例,對控制晶圓沿預設軌跡移動的過程進行說明。In actual detection, in order to facilitate scanning control, the component under test 60 can be placed on the stage 50, and the component under test 60 can be driven to move along a preset trajectory through the overload stage 50. For example, in a specific application scenario, a wafer is taken as an example to describe the process of controlling the wafer to move along a preset trajectory.
檢測前,將晶圓放置在載物台50上,並使得晶圓的圓心O與載物台50的旋轉中心重合,調整第一探測裝置40與晶圓的相對位置,使得第一探測區的延伸方向平行於圓晶半徑方向。調整Nomarski稜鏡方向,使其分光產生的兩束線偏振光的偏離方向垂直於第一探測區的延伸方向。例如,以晶圓圓心O為原點,建立如圖9所示的直角坐標系,第一探測區的延伸方向平行於圖9中的y軸方向,則由Nomarski稜鏡出射的兩束具有微小夾角的線偏振光的偏離方向則平行於圖9中的x軸方向,從而使得物鏡出射的第一偏振光和第二偏振光具有沿圖9中x軸方向的預設剪切量,則所述缺陷檢測設備能夠檢測待測元件60表面沿x軸的凸起或凹陷。在其他實施例中,所述第一偏振光和第二偏振光也可以是具有沿圖9中y軸方向的預設剪切量,或者第一偏振光和第二偏振光的預設剪切量方向與x軸具有銳角夾角。Before inspection, place the wafer on the stage 50, and make the center O of the wafer coincide with the center of rotation of the stage 50, adjust the relative position of the first detection device 40 and the wafer, so that the first detection area The direction of extension is parallel to the direction of the radius of the wafer. Adjust the direction of Nomarski's beam so that the deviation direction of the two beams of linearly polarized light generated by the splitting is perpendicular to the extension direction of the first detection area. For example, taking the wafer center O as the origin, a rectangular coordinate system as shown in Fig. 9 is established, and the extension direction of the first detection area is parallel to the y-axis direction in Fig. 9, and the two beams emitted by Nomarski 稜鏡 have tiny The deviation direction of the angled linearly polarized light is parallel to the x-axis direction in FIG. 9, so that the first polarized light and the second polarized light emitted by the objective lens have a preset shearing amount along the x-axis direction in FIG. 9, so The defect detection equipment is capable of detecting protrusions or depressions on the surface of the component to be tested 60 along the x-axis. In other embodiments, the first polarized light and the second polarized light may also have a preset shearing amount along the y-axis direction in FIG. 9, or a preset shearing of the first polarized light and the second polarized light. The measurement direction has an acute angle with the x-axis.
檢測時,可以通過控制載物台50帶動晶圓運動,從而進行晶圓表面不同位置的檢測,最終實現整個晶圓表面缺陷檢測。具體的,當掃描控制過程為:控制待測表面繞轉軸旋轉一周之後,再控制所述第一偏振光和第二偏振光在待測表面形成的光斑沿待測表面的直徑方向移動時,可以將晶圓劃分為多個環形區域,每個環形區域對應一條掃描軌跡601,多個掃描軌跡601呈同心圓分布,如圖9所示。需要說明的是,為了避免漏檢,相鄰兩個環形區域應相連接或至少有一至兩個圖元(相對於探測器)的重合區域。每個環形區域包括多個目的地區域602,目的地區域602的形狀及尺寸由第一探測裝置40對應的第一探測區的形狀和尺寸決定。首先將移動載物台50使物鏡出射的光斑覆蓋晶圓最外側環形區域中的任意一個目的地區域602,此時,該目的地區域602對應的訊號光被第一探測裝置40接收。然後,控制載物台50帶動晶圓旋轉一周,使光斑按照預設的掃描軌跡601依次經過晶圓最外側環形區域的其他目的地區域602,即對晶圓最外側環形區域進行掃描。完成掃描後,第一探測裝置40所包括的每個探測器均能獲取到晶圓最外側環形區域對應的訊號光檢測資料。During inspection, the wafer can be driven to move by controlling the stage 50, so that different positions on the wafer surface can be inspected, and finally the entire wafer surface defect inspection can be realized. Specifically, when the scanning control process is: after controlling the surface to be measured to rotate one circle around the axis of rotation, and then controlling the light spot formed by the first polarized light and the second polarized light on the surface to be measured to move along the diameter direction of the surface to be measured, The wafer is divided into a plurality of annular areas, and each annular area corresponds to a scan track 601, and the plurality of scan tracks 601 are distributed in concentric circles, as shown in FIG. 9. It should be noted that, in order to avoid missed detection, two adjacent annular areas should be connected or overlapped areas of at least one to two graphic elements (relative to the detector). Each annular area includes a plurality of destination areas 602, and the shape and size of the destination area 602 are determined by the shape and size of the first detection area corresponding to the first detection device 40. First, move the stage 50 so that the light spot emitted by the objective lens covers any destination area 602 in the outermost annular area of the wafer. At this time, the signal light corresponding to the destination area 602 is received by the first detection device 40. Then, the stage 50 is controlled to drive the wafer to rotate once, so that the light spot sequentially passes through other destination areas 602 of the outermost annular area of the wafer according to the preset scanning trajectory 601, that is, scans the outermost annular area of the wafer. After the scanning is completed, each detector included in the first detection device 40 can obtain the signal light detection data corresponding to the outermost annular area of the wafer.
例如,當第一探測裝置40包括四個偏振線探測器,分別為偏振線探測器A、偏振線探測器B、偏振線探測器C和偏振線探測器D時,每個目的地區域602可以分為四個相鄰子區域,一個子區域對應於一個偏振線探測器的第一探測單元區,即每個子區域反射形成的訊號光被對應的偏振線探測器接收。例如,假設目的地區域602包括第一子區域、第二子區域、第三子區域和第四子區域,在控制待測表面繞轉軸旋轉一周的過程中,若當前時刻,當前目的地區域602中第一子區域對應於偏振線探測器A的第一探測單元區,第二子區域對應於偏振線探測器B的第一探測單元區,第三子區域對應於偏振線探測器C的第一探測單元區,第四子區域對應於偏振線探測器D的第一探測單元區。那麼在下一掃描時刻,當前目的地區域602中第二子區域則對應於偏振線探測器A的第一探測單元區,第三子區域對應於偏振線探測器B的第一探測單元區,第四子區域對應於偏振線探測器C的第一探測單元區,下一目的地區域602中的第一子區域對應於偏振線探測器D的第一探測單元區,以此類推,直至完成當前環形區域的掃描。在這個過程中,偏振線探測器A、偏振線探測器B、偏振線探測器C和偏振線探測器D能夠隨著掃描時間的先後依次獲取到當前環形區域對應的訊號光。For example, when the first detection device 40 includes four polarization detectors, namely, polarization detector A, polarization detector B, polarization detector C, and polarization detector D, each destination area 602 may It is divided into four adjacent sub-regions, one sub-region corresponds to the first detection unit area of a polarization detector, that is, the signal light reflected by each sub-region is received by the corresponding polarization detector. For example, suppose that the destination area 602 includes the first sub-area, the second sub-area, the third sub-area, and the fourth sub-area. During the process of controlling the surface to be measured to rotate one circle around the axis of rotation, if the current destination area 602 is The first sub-area corresponds to the first detection unit area of the polarization detector A, the second sub-area corresponds to the first detection unit area of the polarization detector B, and the third sub-area corresponds to the first detection unit area of the polarization detector C. A detection unit area, and the fourth sub-area corresponds to the first detection unit area of the polarization detector D. Then at the next scanning moment, the second sub-area in the current destination area 602 corresponds to the first detection unit area of the polarization detector A, and the third sub-area corresponds to the first detection unit area of the polarization detector B. The four sub-areas correspond to the first detection unit area of the polarization detector C, the first sub-area in the next destination area 602 corresponds to the first detection unit area of the polarization detector D, and so on, until the current Scanning of annulus. In this process, the polarization detector A, the polarization detector B, the polarization detector C, and the polarization detector D can sequentially obtain the signal light corresponding to the current annular area with the sequence of scanning time.
控制待測表面繞轉軸旋轉一周,使得第一偏振光和第二偏振光在待測表面形成的光斑掃描完晶圓表面最外側環形區域後,控制載物台50帶動晶圓沿其直徑方向移動,即使得第一偏振光和第二偏振光在晶圓表面形成的光斑沿與晶圓移動方向相反的方向移動,使得該光斑覆蓋晶圓表面的下一個環形區域中的目的地區域。然後控制載物台50帶動晶圓繞轉軸旋轉一周,完成對該環形區域的掃描,以此類推,直至完成整個晶圓表面的檢測。Control the surface to be measured to rotate one circle around the axis of rotation, so that the light spot formed by the first polarized light and the second polarized light on the surface to be measured scans the outermost annular area of the wafer surface, and then controls the stage 50 to drive the wafer to move along its diameter , That is, the light spot formed by the first polarized light and the second polarized light on the surface of the wafer moves in a direction opposite to the moving direction of the wafer, so that the light spot covers the destination area in the next annular area of the wafer surface. Then the stage 50 is controlled to drive the wafer to rotate one circle around the rotating shaft to complete the scanning of the annular area, and so on, until the inspection of the entire wafer surface is completed.
綜合訊號測量速度及測量橫向解析度,本發明實施例採用線掃描測量,考慮到一般光源出射光均為圓光斑,整形為線光束需要進行額外的光束整形,而本檢測設備對光源強度要求較低,可以採用圓光斑照明加線探測器實現對元件表面線區域的檢測。當然,也可以採用與線探測器的探測區域適配的線光源進行檢測。Integrating signal measurement speed and measurement lateral resolution, the embodiment of the present invention adopts line scanning measurement. Considering that the general light source emits a circular spot, additional beam shaping is required to reshape it into a line beam. However, this detection device has relatively high requirements for the intensity of the light source. Low, circular spot illumination plus line detector can be used to detect the surface line area of the element. Of course, a line light source adapted to the detection area of the line detector can also be used for detection.
作為一種可選的實施方式,執行上述步驟S803之後,所述方法還包括:通過第一處理裝置根據所述訊號光的第一光強分布資訊,獲取所述待測元件60的缺陷資訊。As an optional implementation manner, after performing step S803, the method further includes: obtaining defect information of the component under test 60 according to the first light intensity distribution information of the signal light by the first processing device.
作為一種可選的實施方式,所述根據所述訊號光的第一光強分布資訊,獲取所述待測元件60的缺陷資訊包括:根據所述第一光強分布資訊獲取訊號光的初始資訊;對所述第一光強分布資訊進行低通濾波處理,獲取雜訊資訊;根據所述初始資訊以及雜訊資訊獲取所述待測元件60的缺陷資訊。As an optional implementation manner, the obtaining defect information of the device under test 60 according to the first light intensity distribution information of the signal light includes: obtaining initial information of the signal light according to the first light intensity distribution information ; Perform low-pass filtering on the first light intensity distribution information to obtain noise information; obtain defect information of the component under test 60 according to the initial information and noise information.
作為一種可選的實施方式,所述初始資訊包括訊號光的初始相位資訊,所述雜訊資訊包括雜訊相位資訊。所述根據所述初始資訊以及雜訊資訊獲取所述待測元件60的第一缺陷資訊包括:對所述初始相位資訊和所述雜訊相位資訊進行差值處理,獲取目標相位資訊;根據所述目標相位資訊獲取所述待測元件60的缺陷資訊。As an optional implementation manner, the initial information includes initial phase information of the signal light, and the noise information includes noise phase information. The obtaining the first defect information of the component under test 60 according to the initial information and noise information includes: performing difference processing on the initial phase information and the noise phase information to obtain target phase information; The target phase information acquires defect information of the component under test 60.
作為一種可選的實施方式,所述根據所述目標相位資訊獲取所述待測元件60的缺陷資訊,包括:根據所述目標相位資訊,在預先配置的缺陷標準庫中進行查找相應的預設缺陷資訊,得到待測元件60表面的第一缺陷資訊,其中,所述缺陷標準庫包括多個預設相位資訊與相應預設缺陷資訊之間的對應關係。As an optional implementation manner, the acquiring defect information of the component under test 60 according to the target phase information includes: searching a corresponding preset in a pre-configured defect standard library according to the target phase information Defect information to obtain first defect information on the surface of the component under test 60, wherein the defect standard library includes a plurality of correspondences between preset phase information and corresponding preset defect information.
本發明另一實施例中,缺陷檢測設備還可以為雙通道缺陷檢測設備,即如上述第一實施例中所述的,包括散射光檢測通道和差分干涉法檢測通道。具體來講,如圖7所示,缺陷檢測設備包括第二光產生裝置71、第二探測裝置72和第二處理裝置。In another embodiment of the present invention, the defect detection device may also be a dual-channel defect detection device, that is, as described in the above first embodiment, it includes a scattered light detection channel and a differential interferometry detection channel. Specifically, as shown in FIG. 7, the defect detection equipment includes a second light generating device 71, a second detecting device 72, and a second processing device.
此時,上述缺陷檢測方法包括:通過第一光產生裝置產生第一偏振光和第二偏振光對待測表面進行掃描,並通過第一探測裝置40獲取待測表面的第一光強分布資訊;在通過第一光產生裝置產生第一偏振光和第二偏振光對待測表面進行掃描之後或之前,通過第二光產生裝置71產生第二探測光對待測表面進行掃描,並通過第二探測裝置72獲取待測表面的散射光的第二光強分布資訊;通過第二處理裝置根據第一光強分布資訊得到所述待測元件60的第一缺陷資訊,根據第二光強分布資訊得到待測元件60的第二缺陷資訊,並基於所述第一缺陷資訊和所述第二缺陷資訊得到所述待測元件60的目標缺陷資訊。At this time, the above-mentioned defect detection method includes: generating the first polarized light and the second polarized light by the first light generating device to scan the surface to be tested, and obtaining the first light intensity distribution information of the surface to be tested by the first detecting device 40; After or before scanning the surface to be measured by generating the first polarized light and the second polarized light by the first light generating device, the second light generating device 71 generates the second probe light to scan the surface to be measured, and passes through the second detecting device 72 Obtain the second light intensity distribution information of the scattered light on the surface to be tested; obtain the first defect information of the component under test 60 according to the first light intensity distribution information through the second processing device, and obtain the to-be-tested component 60 according to the second light intensity distribution information. The second defect information of the test component 60 is obtained, and the target defect information of the test component 60 is obtained based on the first defect information and the second defect information.
所屬領域的技術人員可以清楚地瞭解到,為描述的方便和簡潔,上述描述的方法的具體實現過程,可以參考上述裝置實施例中的相應過程,在此不再贅述。Those skilled in the art can clearly understand that, for the convenience and conciseness of the description, the specific implementation process of the above-described method can refer to the corresponding process in the above-mentioned device embodiment, which will not be repeated here.
以上所述,僅為本發明的具體實施方式,但本發明的保護範圍並不局限於此,任何熟悉本技術領域的技術人員在本發明揭露的技術範圍內,可輕易想到變化或替換,都應涵蓋在本發明的保護範圍之內。因此,本發明的保護範圍應所述以申請專利範圍的保護範圍為準。The above are only specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention. It should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the patent application.
1、2:缺陷檢測設備 10:探測光產生模組 20:光束調整模組 30:偏振控制器 40:第一探測裝置 41:第一探測器 42:第二探測器 43:第三探測器 44:第四探測器 50:載物台 60:待測元件 71:第二光產生裝置 72:第二探測裝置 73:第二分束器 74、102:擴束整形裝置 75:第一濾光片 76:第二濾光片 77:會聚透鏡 101:第一光源 103:偏振片 201:第一分束器 202:雙折射晶體 203:物鏡 401、P1~4:第一探測區 600:待測表面 601:掃描軌跡 602:目的地區域 A~D:偏振線探測器 S801~S803:步驟1, 2: Defect detection equipment 10: Probe light generation module 20: Beam adjustment module 30: Polarization controller 40: The first detection device 41: The first detector 42: second detector 43: third detector 44: Fourth Detector 50: stage 60: component under test 71: second light generating device 72: Second detection device 73: Second beam splitter 74, 102: Beam expanding and shaping device 75: first filter 76: second filter 77: Converging lens 101: The first light source 103: Polarizer 201: First beam splitter 202: Birefringent crystal 203: Objective 401, P1~4: the first detection area 600: Surface to be measured 601: Scanning trajectory 602: destination area A~D: Polarization line detector S801~S803: steps
為了更清楚地說明本發明實施例的技術方案,下面將對實施例中所需要使用的圖式作簡單地介紹,應當理解,以下圖式僅示出了本發明的某些實施例,因此不應被看作是對範圍的限定,對於本領域普通技術人員來講,在不付出創造性勞動的前提下,還可以根據這些圖式獲得其他相關的圖式。In order to explain the technical solutions of the embodiments of the present invention more clearly, the following will briefly introduce the drawings that need to be used in the embodiments. It should be understood that the following drawings only show certain embodiments of the present invention, and therefore do not It should be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative work, other related schemas can be obtained based on these schemas.
圖1為本發明第一實施例提供的缺陷檢測設備的一種結構示意圖。Fig. 1 is a schematic structural diagram of a defect detection device provided by a first embodiment of the present invention.
圖2為本發明第一實施例提供的一種第一探測裝置的第一探測區示意圖。FIG. 2 is a schematic diagram of a first detection area of a first detection device provided by the first embodiment of the present invention.
圖3為本發明第一實施例提供的一種探測裝置的結構示意圖。FIG. 3 is a schematic structural diagram of a detection device provided by the first embodiment of the present invention.
圖4為本發明第一實施例提供的一種檢測結果(包含相位雜訊)的相位分布示意圖。4 is a schematic diagram of the phase distribution of a detection result (including phase noise) provided by the first embodiment of the present invention.
圖5為本發明第一實施例提供的一種訊號預處理過程示意圖。FIG. 5 is a schematic diagram of a signal preprocessing process provided by the first embodiment of the present invention.
圖6為本發明第一實施例提供的一種檢測結果(濾除相位雜訊)的相位分布示意圖。FIG. 6 is a schematic diagram of the phase distribution of a detection result (filtering out phase noise) according to the first embodiment of the present invention.
圖7為本發明第一實施例提供的缺陷檢測設備的另一種結構示意圖。FIG. 7 is a schematic diagram of another structure of the defect detection device provided by the first embodiment of the present invention.
圖8為本發明第二實施例提供的一種元件缺陷檢測方法的流程圖。FIG. 8 is a flowchart of a component defect detection method provided by the second embodiment of the present invention.
圖9為本發明第二實施例提供的一種應用場景下晶圓的掃描軌跡示意圖。FIG. 9 is a schematic diagram of a scanning trajectory of a wafer in an application scenario provided by the second embodiment of the present invention.
1:缺陷檢測設備 1: Defect detection equipment
10:探測光產生模組 10: Probe light generation module
20:光束調整模組 20: Beam adjustment module
30:偏振控制器 30: Polarization controller
40:第一探測裝置 40: The first detection device
50:載物台 50: stage
60:待測元件 60: component under test
101:第一光源 101: The first light source
102:擴束整形裝置 102: Expanding beam shaping device
103:偏振片 103: Polarizer
201:第一分束器 201: First beam splitter
202:雙折射晶體 202: Birefringent crystal
203:物鏡 203: Objective

Claims (33)

  1. 一種檢測設備,包括: 光產生調製裝置,用於產生第一偏振光和第二偏振光,使所述第一偏振光經待測元件的待測表面反射形成第一回波光,所述第二偏振光經待測表面反射形成第二回波光,並使所述第一回波光和所述第二回波光發生干涉,形成訊號光,其中,所述第一偏振光和所述第二偏振光中心之間具有預設剪切量;以及 第一探測裝置,用於獲取所述訊號光的第一光強分布資訊,所述第一探測裝置包括兩個以上探測器,所述兩個以上探測器均為偏振探測器,且不同所述偏振探測器的偏振探測方向不同,或者,所述兩個以上探測器包括無偏振探測器和至少一個偏振探測器。A testing equipment, including: The light generating and modulating device is used to generate the first polarized light and the second polarized light, so that the first polarized light is reflected by the surface to be measured of the component to be measured to form a first echo light, and the second polarized light passes through the surface to be measured The reflection forms the second echo light, and causes the first echo light and the second echo light to interfere to form signal light, wherein there is a predetermined center between the first polarized light and the second polarized light. Shear amount; and The first detection device is used to obtain the first light intensity distribution information of the signal light. The first detection device includes two or more detectors, and the two or more detectors are all polarization detectors, and are different from each other. The polarization detection directions of the polarization detectors are different, or the two or more detectors include a non-polarization detector and at least one polarization detector.
  2. 如請求項1所述之檢測設備,其中,所述第一探測裝置包括第一探測區,所述第一探測區用於對所述待測表面進行掃描;所述第一探測區包括多個第一探測單元區,所述多個第一探測單元區的排列方向與所述第一探測區在所述待測表面的掃描方向不垂直,各個所述探測器用於分別探測不同所述第一探測單元區對應的所述待測表面反射回的訊號光。The detection device according to claim 1, wherein the first detection device includes a first detection area, and the first detection area is used to scan the surface to be measured; and the first detection area includes a plurality of The first detection unit area, the arrangement direction of the plurality of first detection unit areas is not perpendicular to the scanning direction of the first detection area on the surface to be measured, and each of the detectors is used to detect different first The signal light reflected back from the surface to be measured corresponding to the detection unit area.
  3. 如請求項2所述之檢測設備,其中,所述多個第一探測單元區的排列方向平行於所述第一探測區對所述待測表面的掃描方向。The detection device according to claim 2, wherein the arrangement direction of the plurality of first detection unit areas is parallel to the scanning direction of the first detection area to the surface to be measured.
  4. 如請求項2所述之檢測設備,其中,所述第一探測區為條形,所述第一探測區的延伸方向垂直於所述第一探測區對所述待測表面的掃描方向。The detection device according to claim 2, wherein the first detection area is strip-shaped, and the extension direction of the first detection area is perpendicular to the scanning direction of the first detection area to the surface to be measured.
  5. 如請求項4所述之檢測設備,其中,當所述待測元件的待測表面為圓形時,所述第一探測區沿著所述待測表面的徑向延伸;所述第一探測區對所述待測元件的待測表面的掃描方向垂直於所述待測表面的直徑方向。The detection device according to claim 4, wherein, when the surface to be measured of the component to be measured is circular, the first detection area extends along the radial direction of the surface to be measured; the first detection The scanning direction of the area to the surface to be tested of the component to be tested is perpendicular to the diameter direction of the surface to be tested.
  6. 如請求項2所述之檢測設備,其中,所述第一偏振光和所述第二偏振光用於在所述待測表面形成探測光斑;在沿所述第一探測區對所述待測表面的掃描方向上,所述探測光斑的尺寸大於或等於所述第一探測區的尺寸。The detection device according to claim 2, wherein the first polarized light and the second polarized light are used to form a detection spot on the surface to be measured; In the scanning direction of the surface, the size of the detection spot is greater than or equal to the size of the first detection area.
  7. 如請求項1所述之檢測設備,其中,每個所述偏振探測器均為偏振線探測器,所述無偏振探測器為線探測器。The detection device according to claim 1, wherein each of the polarization detectors is a polarization line detector, and the non-polarization detector is a line detector.
  8. 如請求項1所述之檢測設備,其中,所述偏振探測器的個數為兩個時,兩個所述偏振探測器的偏振探測方向相互垂直。The detection device according to claim 1, wherein when the number of the polarization detectors is two, the polarization detection directions of the two polarization detectors are perpendicular to each other.
  9. 如請求項1所述之檢測設備,其中,當所述第一探測裝置包括三個及以上偏振探測器時,所述三個及以上偏振探測器包括第一偏振探測器、第二偏振探測器和第三偏振探測器,其中,所述第三偏振探測器和所述第一偏振探測器的偏振探測方向之間的夾角等於360°/n,n 為大於等於3的整數,n為偏振探測器的個數。The detection device according to claim 1, wherein, when the first detection device includes three or more polarization detectors, the three or more polarization detectors include a first polarization detector and a second polarization detector And a third polarization detector, wherein the angle between the polarization detection directions of the third polarization detector and the first polarization detector is equal to 360°/n, n is an integer greater than or equal to 3, and n is the polarization detection The number of devices.
  10. 如請求項9所述之檢測設備,其中,所述第一偏振探測器與所述第三偏振探測器的偏振探測方向垂直,所述第三偏振探測器與所述第二偏振探測器的偏振探測方向之間的夾角為45°。The detection device according to claim 9, wherein the polarization detection direction of the first polarization detector is perpendicular to the polarization detection direction of the third polarization detector, and the polarization detection direction of the third polarization detector is perpendicular to that of the second polarization detector. The angle between the detection directions is 45°.
  11. 如請求項1所述之檢測設備,其中,當所述第一探測裝置包括無偏振探測器和至少一個偏振探測器時,所述偏振探測器的個數為兩個及以上,其中兩個偏振探測器的偏振探測方向之間的夾角為銳角或鈍角。The detection device according to claim 1, wherein, when the first detection device includes a non-polarization detector and at least one polarization detector, the number of the polarization detectors is two or more, of which two polarization detectors The angle between the polarization detection directions of the detector is an acute or obtuse angle.
  12. 如請求項1所述之檢測設備,其中,所述光產生調製裝置包括: 第一光產生裝置,用於產生第一偏振光和第二偏振光,所述第一偏振光和所述第二偏振光中心之間具有預設剪切量,所述第一偏振光經待測表面反射形成第一回波光,所述第二偏振光經待測表面反射形成第二回波光,並使所述第一回波光和所述第二回波光合束;及 偏振控制器,用於調製所述第一回波光和所述第二回波光的偏振方向,以使得所述第一回波光和所述第二回波光發生干涉,形成訊號光。The detection device according to claim 1, wherein the light generating and modulating device includes: The first light generating device is used to generate the first polarized light and the second polarized light. There is a preset shear amount between the center of the first polarized light and the second polarized light. The measurement surface reflects to form a first echo light, the second polarized light is reflected by the surface to be measured to form a second echo light, and the first echo light and the second echo light are combined; and The polarization controller is used to modulate the polarization directions of the first echo light and the second echo light, so that the first echo light and the second echo light interfere to form signal light.
  13. 如請求項12所述之檢測設備,其中,所述第一光產生裝置包括探測光產生模組和光束調整模組,所述探測光產生模組和所述光束調整模組耦合; 所述探測光產生模組用於產生第一探測光; 所述光束調整模組用於將所述第一探測光分成所述第一偏振光和所述第二偏振光,並使所述第一回波光和所述第二回波光合束。The detection device according to claim 12, wherein the first light generating device includes a probe light generating module and a beam adjusting module, and the probe light generating module is coupled with the beam adjusting module; The detection light generating module is used to generate the first detection light; The beam adjustment module is used to divide the first probe light into the first polarized light and the second polarized light, and combine the first echo light and the second echo light.
  14. 如請求項13所述之檢測設備,其中,所述探測光產生模組包括第一光源和擴束整形裝置,所述第一光源用於產生第一探測光,所述擴束整形裝置用於控制所述待測表面的光斑形狀和尺寸。The detection device according to claim 13, wherein the probe light generating module includes a first light source and a beam expanding and shaping device, the first light source is used for generating the first probe light, and the beam expanding and shaping device is used for Control the spot shape and size of the surface to be measured.
  15. 如請求項13所述之檢測設備,其中,所述第一探測光為線偏振光、圓偏振光或橢圓偏振光。The detection device according to claim 13, wherein the first detection light is linearly polarized light, circularly polarized light, or elliptically polarized light.
  16. 如請求項1所述之檢測設備,其中,所述檢測設備還包括第一處理裝置; 所述第一處理裝置用於根據所述訊號光的第一光強分布資訊獲取所述待測元件的缺陷資訊。The detection device according to claim 1, wherein the detection device further includes a first processing device; The first processing device is used for obtaining defect information of the component under test according to the first light intensity distribution information of the signal light.
  17. 如請求項16所述之檢測設備,其中,所述第一處理裝置包括: 訊號解調模組,用於根據所述訊號光的第一光強分布資訊獲取訊號光的初始資訊; 雜訊獲取模組,用於對所述訊號光的第一光強分布資訊進行低通濾波處理,獲取雜訊資訊;及 目標資訊獲取模組,用於根據所述初始資訊以及所述雜訊資訊獲取所述待測元件的缺陷資訊。The detection device according to claim 16, wherein the first processing device includes: The signal demodulation module is used to obtain the initial information of the signal light according to the first light intensity distribution information of the signal light; A noise acquisition module for performing low-pass filtering processing on the first light intensity distribution information of the signal light to acquire noise information; and The target information acquisition module is used for acquiring defect information of the component under test according to the initial information and the noise information.
  18. 如請求項17所述之檢測設備,其中,所述初始資訊包括訊號光的初始相位資訊,所述雜訊資訊包括雜訊相位資訊; 所述目標資訊獲取模組包括: 目標相位獲取子模組,用於對所述初始相位資訊和所述雜訊相位資訊進行差值處理,獲取目標相位資訊;及 缺陷資訊獲取子模組,用於根據所述目標相位資訊獲取所述待測元件的缺陷資訊。The detection device according to claim 17, wherein the initial information includes initial phase information of the signal light, and the noise information includes noise phase information; The target information acquisition module includes: The target phase obtaining sub-module is used to perform difference processing on the initial phase information and the noise phase information to obtain target phase information; and The defect information acquisition sub-module is used to acquire defect information of the component under test according to the target phase information.
  19. 如請求項18所述之檢測設備,其中,所述目標資訊獲取模組還包括:缺陷標準庫,所述缺陷標準庫包括預設相位資訊和預設缺陷資訊,用於確定所述預設相位資訊與所述預設缺陷資訊之間的對應關係;所述缺陷資訊獲取子模組具體用於根據所述目標相位資訊在所述缺陷標準庫中進行查找,獲取相應的預設缺陷資訊,得到所述待測元件的缺陷資訊。The inspection device according to claim 18, wherein the target information acquisition module further includes: a defect standard library, the defect standard library including preset phase information and preset defect information, for determining the preset phase The corresponding relationship between the information and the preset defect information; the defect information acquisition sub-module is specifically used to search in the defect standard library according to the target phase information, obtain corresponding preset defect information, and obtain Defect information of the component under test.
  20. 如請求項1所述之檢測設備,其中,所述檢測設備還包括: 第二探測裝置,用於收集所述待測表面的散射光,並獲取所述散射光的第二光強分布資訊;及 第二處理裝置,用於根據所述第一光強分布資訊獲取所述待測元件的第一缺陷資訊,根據所述第二光強分布資訊獲取所述待測元件的第二缺陷資訊,並基於所述第一缺陷資訊和所述第二缺陷資訊得到所述待測元件的目標缺陷資訊。The detection device according to claim 1, wherein the detection device further includes: The second detection device is used to collect scattered light from the surface to be measured and obtain second light intensity distribution information of the scattered light; and The second processing device is configured to obtain first defect information of the component under test according to the first light intensity distribution information, and obtain second defect information of the component under test according to the second light intensity distribution information, and Obtain target defect information of the component under test based on the first defect information and the second defect information.
  21. 如請求項20所述之檢測設備,其還包括: 第二光產生裝置,用於產生第二探測光,並使所述第二探測光經所述待測表面散射,形成所述散射光。The detection device according to claim 20, which further includes: The second light generating device is used to generate second probe light, and cause the second probe light to be scattered by the surface to be measured to form the scattered light.
  22. 一種檢測方法,其係應用於如請求項1至21中任一項所述之檢測裝置,所述方法包括以下步驟: 通過光產生調製裝置產生第一偏振光和第二偏振光,並使所述第一偏振光經待測元件的待測表面反射形成第一回波光,所述第二偏振光經所述待測表面反射形成第二回波光,其中,所述第一偏振光和所述第二偏振光中心之間具有預設剪切量; 通過所述光產生調製裝置使所述第一回波光和所述第二回波光發生干涉,形成訊號光; 通過第一探測裝置獲取所述訊號光沿多個不同偏振方向的光強資訊,或者獲取所述訊號光總的光強資訊以及至少沿一個偏振方向的光強資訊。A detection method, which is applied to the detection device according to any one of Claims 1 to 21, the method includes the following steps: The first polarized light and the second polarized light are generated by the light generating and modulating device, and the first polarized light is reflected by the surface to be tested of the component to be tested to form the first echo light, and the second polarized light is passed through the tested surface. The surface reflects to form a second echo light, wherein there is a predetermined amount of shear between the centers of the first polarized light and the second polarized light; The first echo light and the second echo light are interfered by the light generating and modulating device to form signal light; Obtain the light intensity information of the signal light along a plurality of different polarization directions by the first detection device, or obtain the total light intensity information of the signal light and the light intensity information along at least one polarization direction.
  23. 如請求項22所述之檢測方法,其中,當所述第一探測裝置包括第一探測區,所述第一探測區包括多個第一探測單元區時; 所述方法還包括以下步驟: 控制所述第一偏振光和所述第二偏振光在所述待測表面掃描,並重複形成訊號光和獲取光強資訊的步驟。The detection method according to claim 22, wherein, when the first detection device includes a first detection area, and the first detection area includes a plurality of first detection unit areas; The method also includes the following steps: The first polarized light and the second polarized light are controlled to scan on the surface to be measured, and the steps of forming signal light and obtaining light intensity information are repeated.
  24. 如請求項23所述之檢測方法,其中,所述第一偏振光和所述第二偏振光在所述待測表面的掃描方向與所述多個第一探測單元區的排列方向相同。The detection method according to claim 23, wherein the scanning direction of the first polarized light and the second polarized light on the surface to be measured is the same as the arrangement direction of the plurality of first detection unit regions.
  25. 如請求項24所述之檢測方法,其中,獲取所述光強資訊的步驟包括:通過所述第一探測裝置對所述訊號光的光強資訊進行採樣,相鄰兩次採樣的時間間隔內,所述第一探測區掃描的距離為掃描步長,相鄰所述第一探測單元區中心之間的距離等於所述掃描步長的整數倍。The detection method according to claim 24, wherein the step of obtaining the light intensity information includes: sampling the light intensity information of the signal light by the first detection device, and within a time interval of two adjacent samples The scanning distance of the first detection area is a scanning step length, and the distance between the centers of adjacent first detection unit areas is equal to an integer multiple of the scanning step length.
  26. 如請求項25所述之檢測方法,其中,相鄰所述第一探測單元區中心之間的距離等於所述掃描步長。The detection method according to claim 25, wherein the distance between the centers of adjacent first detection unit regions is equal to the scan step length.
  27. 如請求項23所述之檢測方法,其中,所述控制所述第一偏振光和所述第二偏振光在所述待測表面掃描的步驟包括:控制所述待測元件的待測表面沿與所述掃描方向相反的方向移動。The detection method according to claim 23, wherein the step of controlling the scanning of the first polarized light and the second polarized light on the surface to be measured includes: controlling the edge of the surface to be measured of the element to be measured Move in a direction opposite to the scanning direction.
  28. 如請求項27所述之檢測方法,其中,所述控制所述待測元件的待測表面沿與所述掃描方向相反的方向移動的步驟包括:控制所述待測元件繞垂直於所述待測表面的轉軸旋轉; 所述控制所述第一偏振光和所述第二偏振光在所述待測表面掃描的步驟還包括:當所述待測表面繞所述轉軸旋轉一周之後或者在所述待測表面繞所述轉軸旋轉的過程中,控制所述第一偏振光和所述第二偏振光在所述待測表面形成的光斑沿所述待測表面的直徑方向移動。The detection method according to claim 27, wherein the step of controlling the surface to be tested of the component to be tested to move in a direction opposite to the scanning direction comprises: controlling the component to be tested to move around perpendicular to the scanning direction. Rotation of the shaft of the measuring surface; The step of controlling the scanning of the first polarized light and the second polarized light on the surface to be measured further includes: after the surface to be measured rotates once around the axis of rotation, or after the surface to be measured rotates around the surface to be measured During the rotation of the shaft, the light spot formed by the first polarized light and the second polarized light on the surface to be measured is controlled to move along the diameter direction of the surface to be measured.
  29. 如請求項23所述之檢測方法,其中,當所述光產生調製裝置包括第一光源和擴束整形裝置時, 所述產生第一偏振光和第二偏振光的步驟包括: 通過所述第一光源產生第一探測光,以基於所述第一探測光形成第一偏振光和第二偏振光; 通過所述擴束整形裝置調整所述第一偏振光和所述第二偏振光在待測元件的待測表面所形成的光斑形狀和尺寸,使在沿所述第一探測區對所述待測表面的掃描方向上,所述探測光斑的尺寸大於或等於所述第一探測區的尺寸。The detection method according to claim 23, wherein, when the light generating and modulating device includes a first light source and a beam expanding and shaping device, The step of generating the first polarized light and the second polarized light includes: Generating first probe light by the first light source to form first polarized light and second polarized light based on the first probe light; The shape and size of the spot formed by the first polarized light and the second polarized light on the surface to be measured of the component to be measured are adjusted by the beam expander and shaping device, so that the spot shape and size formed by the first polarized light and the second polarized light are aligned along the first detection area. In the scanning direction of the measuring surface, the size of the detection spot is greater than or equal to the size of the first detection area.
  30. 如請求項22所述之檢測方法,其中,將所述第一探測裝置獲取到的所述訊號光沿多個不同偏振方向的光強資訊,或者所述訊號光總的光強資訊以及至少沿一個偏振方向的光強資訊作為所述訊號光的第一光強分布資訊,獲取到所述第一光強分布資訊之後,所述檢測方法還包括: 根據所述訊號光的第一光強分布資訊,獲取所述待測元件的缺陷資訊。The detection method according to claim 22, wherein the light intensity information along a plurality of different polarization directions of the signal light acquired by the first detection device, or the total light intensity information of the signal light and at least along The light intensity information of one polarization direction is used as the first light intensity distribution information of the signal light. After the first light intensity distribution information is obtained, the detection method further includes: Obtaining defect information of the component under test according to the first light intensity distribution information of the signal light.
  31. 如請求項30所述之檢測方法,其中,所述根據所述訊號光的第一光強分布資訊,獲取所述待測元件的缺陷資訊包括以下步驟: 根據所述第一光強分布資訊獲取訊號光的初始資訊; 對所述第一光強分布資訊進行低通濾波處理,獲取雜訊資訊;及 根據所述初始資訊以及所述雜訊資訊獲取所述待測元件的缺陷資訊。The inspection method according to claim 30, wherein the acquiring defect information of the component under test according to the first light intensity distribution information of the signal light includes the following steps: Acquiring the initial information of the signal light according to the first light intensity distribution information; Performing low-pass filtering processing on the first light intensity distribution information to obtain noise information; and Obtain defect information of the component under test according to the initial information and the noise information.
  32. 如請求項31所述之檢測方法,其中,所述初始資訊包括訊號光的初始相位資訊,所述雜訊資訊包括雜訊相位資訊; 所述根據所述初始資訊以及所述雜訊資訊獲取所述待測元件的缺陷資訊包括: 對所述初始相位資訊和所述雜訊相位資訊進行差值處理,獲取目標相位資訊;及 根據所述目標相位資訊獲取所述待測元件的缺陷資訊。The detection method according to claim 31, wherein the initial information includes initial phase information of the signal light, and the noise information includes noise phase information; The obtaining defect information of the component under test according to the initial information and the noise information includes: Performing difference processing on the initial phase information and the noise phase information to obtain target phase information; and Obtain defect information of the component under test according to the target phase information.
  33. 如請求項32所述之檢測方法,其中,所述根據所述目標相位資訊獲取所述待測元件的缺陷資訊的步驟包括: 根據所述目標相位資訊,在預先配置的缺陷標準庫中進行查找相應的預設缺陷資訊,得到所述待測表面的缺陷資訊,其中,所述缺陷標準庫包括多個預設相位資訊與相應預設缺陷資訊之間的對應關係。The inspection method according to claim 32, wherein the step of obtaining defect information of the component under test according to the target phase information includes: According to the target phase information, the corresponding preset defect information is searched in the pre-configured defect standard library to obtain the defect information of the surface to be tested, wherein the defect standard library includes a plurality of preset phase information and corresponding Correspondence between default defect information.
TW108124552A 2019-07-11 2019-07-11 Detection apparatus and detection method thereof for effectively realizing the polarization state analysis of the signal light and realize a high-precision detection of the component under test in the longitudinal direction TW202102841A (en)

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