公开(公告)号：WO2012062501A1

公开(公告)日：2012-05-18

申请号：PCT/EP2011/066038

申请日：2011-09-15

Applicant: ASML NETHERLANDS B.V. ,  SMILDE, Hendrik ,  WARNAAR, Patrick

Inventor： SMILDE, Hendrik ,  WARNAAR, Patrick

IPC: G03F7/20

CPC classification number: G03F9/00 ,  G03F7/70483 ,  G03F7/70633

Abstract: Methods are disclosed for measuring target structures formed by a lithographic process on a substrate. A grating or other structure within the target is smaller than an illumination spot and field of view of a measurement optical system. The position of an image of the component structure varies between measurements, and a first type of correction is applied to reduce the influence on the measured intensities, caused by differences in the optical path to and from different positions. A plurality of structures may be imaged simultaneously within the field of view of the optical system, and each corrected for its respective position. The measurements may comprise first and second images of the same target under different modes of illumination and/or imaging, for example in a dark field metrology application. A second type of correction may be applied to reduce the influence of asymmetry between the first and second modes of illumination or imaging, for example to permit a more accurate overly measurement in a semiconductor device manufacturing process.

Abstract translation: 公开了用于测量由基板上的光刻工艺形成的目标结构的方法。 目标内的光栅或其他结构小于测量光学系统的照明点和视场。 组件结构的图像的位置在测量之间变化，并且应用第一类型的校正以减少由与来自不同位置的光路的差异引起的对测量的强度的影响。 可以在光学系统的视野内同时成像多个结构，并且每个结构被校正为其各自的位置。 测量可以包括在不同照明和/或成像模式下的相同目标的第一和第二图像，例如在暗场测量应用中。 可以应用第二类型的校正来减少第一和第二照明模式或成像之间的不对称性的影响，例如允许在半导体器件制造过程中更准确地过度测量。

公开(公告)号：WO2010025950A1

公开(公告)日：2010-03-11

申请号：PCT/EP2009/006473

申请日：2009-09-07

Applicant: ASML NETHERLANDS B.V. ,  SMILDE, Hendrik ,  COENE, Willem

Inventor： SMILDE, Hendrik ,  COENE, Willem

IPC: G03F7/20

CPC classification number: G03F7/70683 ,  G03F7/70625 ,  G03F7/70633 ,  Y10T428/24802

Abstract: A target for measuring an overlay error or a critical dimension of a substrate comprises a grating. In one example, lines of the grating are arranged at an angle of about 45° with respect to edges of the target. As a consequence, the diffraction order of the grating reflection has its sub-maxima not aligned along the line on which the other diffraction orders are positioned, and overlap of intensity with other diffraction orders is reduced

Abstract translation: 用于测量衬底的重叠误差或临界尺寸的目标包括光栅。 在一个示例中，光栅的线相对于目标的边缘以约45°的角度布置。 因此，光栅反射的衍射级具有其沿着其它衍射级所在的线不对准的亚极大值，并且强度与其它衍射级的重叠减少

公开(公告)号：WO2011023517A1

公开(公告)日：2011-03-03

申请号：PCT/EP2010/061379

申请日：2010-08-05

Applicant: ASML Netherlands B.V. ,  SMILDE, Hendrik ,  DEN BOEF, Arie ,  COENE, Willem ,  BLEEKER, Arno ,  KOOLEN, Armand ,  PELLEMANS, Henricus ,  PLUG, Reinder

Inventor： SMILDE, Hendrik ,  DEN BOEF, Arie ,  COENE, Willem ,  BLEEKER, Arno ,  KOOLEN, Armand ,  PELLEMANS, Henricus ,  PLUG, Reinder

IPC: G03F7/20

CPC classification number: G03F7/70633 ,  G03F7/70616

Abstract: A metrology apparatus is arranged to illuminate a plurality of targets with an off-axis illumination mode. Images of the targets are obtained using only one first order diffracted beam. Where the target is a composite grating, overlay measurements can be obtained from the intensities of the images of the different gratings. Overlay measurements can be corrected for errors caused by variations in the position of the gratings in an image field.

Abstract translation: 计量装置被布置成以离轴照明模式照射多个目标。 仅使用一个一阶衍射光束获得目标图像。 在目标是复合光栅的地方，可以从不同光栅的图像的强度获得覆盖测量。 可以对由图像场中的光栅位置的变化引起的误差来校正叠加测量。

公开(公告)号：WO2011012624A1

公开(公告)日：2011-02-03

申请号：PCT/EP2010/060894

申请日：2010-07-27

Applicant: ASML Netherlands B.V. ,  CRAMER, Hugo ,  DEN BOEF, Arie ,  MEGENS, Henricus ,  SMILDE, Hendrik ,  SCHELLEKENS, Adrianus ,  KUBIS, Michael

Inventor： CRAMER, Hugo ,  DEN BOEF, Arie ,  MEGENS, Henricus ,  SMILDE, Hendrik ,  SCHELLEKENS, Adrianus ,  KUBIS, Michael

IPC: G03F7/20

CPC classification number: G03F7/70641 ,  G01B11/02 ,  G01B11/22 ,  G01B11/24 ,  G01B11/30 ,  G01N21/47 ,  G01N21/88 ,  G03F7/70608 ,  G03F7/70625 ,  G03F7/70633 ,  G03F7/7065

Abstract: In a method of determining the focus of a lithographic apparatus used in a lithographic process on a substrate, the lithographic process is used to form a structure on the substrate, the structure having at least one feature which has an asymmetry in the printed profile which varies as a function of the focus of the lithographic apparatus on the substrate. A first image of the periodic structure is formed and detected while illuminating the structure with a first beam of radiation, the first image being formed using a first part of non-zero order diffracted radiation. A second image of the periodic structure is formed and detected while illuminating the structure with a second beam of radiation. The second image is formed using a second part of the non-zero order diffracted radiation which is symmetrically opposite to the first part in a diffraction spectrum. The ratio of the intensities of the measured first and second portions of the spectra is determined and used to determine the asymmetry in the profile of the periodic structure and/or to provide an indication of the focus on the substrate. In the same instrument, an intensity variation across the detected portion is determined as a measure of process-induced variation across the structure. A region of the structure with unwanted process variation can be identified and excluded from a measurement of the structure.

Abstract translation: 在确定在基板上的光刻工艺中使用的光刻设备的焦点的方法中，使用光刻工艺在衬底上形成结构，该结构具有至少一个特征，该特征在印刷轮廓中具有不对称性 作为光刻设备在基板上的焦点的函数。 在用第一辐射束照射结构的同时形成和检测周期性结构的第一图像，第一图像使用非零次衍射辐射的第一部分形成。 在用第二辐射束照射结构的同时形成和检测周期性结构的第二图像。 使用在衍射光谱中与第一部分对称相对的非零级衍射辐射的第二部分形成第二图像。 确定测量的第一和第二部分光谱的强度的比率并用于确定周期性结构的轮廓的不对称性和/或提供焦点在基底上的指示。 在相同的仪器中，被检测部分的强度变化被确定为整个结构的过程引起的变化的量度。 可以从结构的测量中识别并排除具有不期望的工艺变化的结构区域。

公开(公告)号：WO2014005828A1

公开(公告)日：2014-01-09

申请号：PCT/EP2013/062516

申请日：2013-06-17

Applicant: ASML NETHERLANDS B.V.

Inventor： VAN DER SCHAAR, Maurits ,  BHATTACHARYYA, Kaustuve ,  SMILDE, Hendrik

IPC: G03F7/20

CPC classification number: G01B11/27 ,  G01B11/30 ,  G03F7/20 ,  G03F7/70633 ,  H01L23/544 ,  H01L2924/0002 ,  H01L2924/00

Abstract: A lithographic process is used to form a plurality of target structures (92, 94) distributed at a plurality of locations across a substrate and having overlaid periodic structures with a number of different overlay bias values distributed across the target structures. At least some of the target structures comprise a number of overlaid periodic structures (e.g., gratings) that is fewer than said number of different overlay bias values. Asymmetry measurements are obtained for the target structures. The detected asymmetries are used to determine parameters of a lithographic process. Overlay model parameters including translation, magnification and rotation, can be calculated while correcting the effect of bottom grating asymmetry, and using a multi-parameter model of overlay error across the substrate.

Abstract translation: 使用光刻工艺来形成分布在跨越衬底的多个位置处的多个目标结构（92,94），并且具有跨过目标结构分布的多个不同覆盖偏压值的重叠周期结构。 目标结构中的至少一些包括少于所述数量的不同叠加偏置值的多个重叠的周期性结构（例如光栅）。 获得目标结构的不对称测量值。 检测到的不对称性用于确定光刻工艺的参数。 可以在校正底部光栅不对称的影响的同时使用包括平移，放大和旋转在内的叠加模型参数，并使用跨衬底的重叠误差的多参数模型。

公开(公告)号：WO2013178422A1

公开(公告)日：2013-12-05

申请号：PCT/EP2013/059061

申请日：2013-05-01

Applicant: ASML NETHERLANDS B.V.

Inventor： JAK, Martin ,  KOOLEN, Armand ,  SMILDE, Hendrik

IPC: G03F7/20

CPC classification number: G03F7/70625 ,  G03F7/70483 ,  G03F7/70633 ,  G03F7/70683

Abstract: A metrology target formed by a lithographic process on a substrate includes a plurality of component gratings. Images of the target are formed using +1 and -1 orders of radiation diffracted by the component gratings. Regions of interest (ROIs) in the detected image are identified corresponding the component gratings. Intensity values within each ROI are processed and compared between images, to obtain a measurement of asymmetry and hence overlay error. Separation zones are formed between the component gratings and design so as to provide dark regions in the image. In an embodiment, the ROIs are selected with their boundaries falling within the image regions corresponding to the separation zones. By this measure, the asymmetry measurement is made more tolerant of variations in the position of the ROI. The dark regions also assist in recognition of the target in the images.

Abstract translation: 由基板上的光刻工艺形成的测量目标包括多个分量光栅。 使用由分量光栅衍射的+1和-1次辐射来形成目标的图像。 识别检测到的图像中的感兴趣区域（ROI）对应于分量光栅。 在每个ROI内的强度值被处理并在图像之间进行比较，以获得不对称性的测量并因此获得覆盖误差。 在分量光栅之间形成分离区并设计成在图像中提供暗区。 在一个实施例中，选择其边界落入对应于分离区域的图像区域内的ROI。 通过这种措施，使不对称测量更加容忍ROI的位置的变化。 黑暗的地区也有助于识别图像中的目标。

公开(公告)号：WO2012062858A1

公开(公告)日：2012-05-18

申请号：PCT/EP2011/069845

申请日：2011-11-10

Applicant: ASML NETHERLANDS B.V. ,  SMILDE, Hendrik ,  BLEEKER, Arno ,  COENE, Willem ,  KUBIS, Michael ,  WARNAAR, Patrick

Inventor： SMILDE, Hendrik ,  BLEEKER, Arno ,  COENE, Willem ,  KUBIS, Michael ,  WARNAAR, Patrick

IPC: G03F7/20 ,  G01N21/956

CPC classification number: G03F7/70633 ,  G03F7/70483 ,  G03F7/70625 ,  G03F7/70641 ,  G06N99/005

Abstract: Methods are disclosed for measuring target structures (32-35) formed by a lithographic process on a substrate (W). A grating structure within said target is smaller than an illumination spot (31) and field of view of a measurement optical system. The optical system has a first branch leading to a pupil plane imaging sensor (19) and a second branch leading to a substrate plane imaging sensor (23). A spatial light modulator (SLM) (24, 124, 224, 324) is arranged in an intermediate pupil plane of the second branch of the optical system. The SLM imparts a programmable pattern of attenuation that may be used to correct for asymmetries between the first and second modes of illumination or imaging. By use of specific target designs and machine-learning processes, the attenuation patterns may also be programmed to act as filter functions, enhancing sensitivity to specific parameters of interest, such as focus.

Abstract translation: 公开了用于测量由基板（W）上的光刻工艺形成的目标结构（32-35）的方法。 所述目标内的光栅结构小于测量光学系统的照明光点（31）和视场。 光学系统具有通向光瞳平面成像传感器（19）的第一分支和通向基板平面成像传感器（23）的第二分支。 空间光调制器（SLM）（24,124,224,324）被布置在光学系统的第二分支的中间光瞳平面中。 SLM赋予可编程的衰减模式，其可用于校正第一和第二照明模式或成像之间的不对称性。 通过使用特定的目标设计和机器学习过程，衰减模式也可以被编程为充当滤波器功能，增强对诸如焦点的特定参数的敏感性。

公开(公告)号：WO2013143814A1

公开(公告)日：2013-10-03

申请号：PCT/EP2013/054504

申请日：2013-03-06

Applicant: ASML NETHERLANDS B.V.

Inventor： SMILDE, Hendrik ,  ADAM, Omer

IPC: G03F7/20

CPC classification number: G01N21/956 ,  G03F7/70633 ,  G03F7/70683 ,  G03F9/7019 ,  Y10T428/24802

Abstract: A lithographic process is used to form a plurality of target structures (T) on a substrate (W). Each target structure comprises overlaid gratings each having a specific overlay bias. Asymmetry (A) of each grating, measured by scatterometry, includes contributions due to (i) the overlay bias, (ii) an overlay error (OV) in the lithographic process and (iii) bottom grating asymmetry within the overlaid gratings. Asymmetry measurements are obtained for three or more target structures having three or more different values of overlay bias (e.g., –d, 0, +d). Knowing the three different overlay bias values and a theoretical curve relationship between overlay error and asymmetry, overlay error (OV) can be calculated while correcting the effect of bottom grating asymmetry. Bias schemes with three and four different biases are disclosed as examples. Gratings with different directions and biases can be interleaved in a composite target structure.

Abstract translation: 使用光刻工艺在衬底（W）上形成多个靶结构（T）。 每个目标结构包括各自具有特定覆盖偏压的重叠光栅。 通过散射测量，每个光栅的不对称（A）包括由于（i）叠加偏压，（ii）平版印刷工艺中的覆盖误差（OV）和（iii）覆盖光栅内的底部光栅不对称引起的贡献。 对于具有三个或更多个不同重叠偏置值（例如，d，0，+ d）的三个或更多个目标结构，获得不对称测量。 知道三种不同的叠加偏差值和叠加误差与不对称性之间的理论曲线关系，可以计算出叠加误差（OV），同时校正底​​部光栅不对称的影响。 作为示例公开了具有三种和四种不同偏差的偏置方案。 具有不同方向和偏差的光栅可以在复合目标结构中交错。

公开(公告)号：WO2012126684A1

公开(公告)日：2012-09-27

申请号：PCT/EP2012/052862

申请日：2012-02-20

Applicant: ASML NETHERLANDS B.V. ,  VAN DER SCHAAR, Maurits ,  WARNAAR, Patrick ,  BHATTACHARYYA, Kaustuve ,  SMILDE, Hendrik ,  KUBIS, Michael

Inventor： VAN DER SCHAAR, Maurits ,  WARNAAR, Patrick ,  BHATTACHARYYA, Kaustuve ,  SMILDE, Hendrik ,  KUBIS, Michael

IPC: G03F7/20

CPC classification number: G03F9/7042 ,  G03F7/70616 ,  G03F7/70633 ,  G03F7/70683 ,  H01L23/544 ,  H01L23/58 ,  H01L2924/0002 ,  H01L2924/00

Abstract: A pattern from a patterning device is applied to a substrate by a lithographic apparatus. The applied pattern includes product features and metrology targets. The metrology targets include large targets and small targets which are for measuring overlay. Some of the smaller targets are distributed at locations between the larger targets, while other small targets are placed at the same locations as a large target. By comparing values measured using a small target and large target at the same location, parameter values measured using all the small targets can be corrected for better accuracy. The large targets can be located primarily within scribe lanes while the small targets are distributed within product areas.

Abstract translation: 来自图案形成装置的图案通过光刻装置施加到基板。 应用模式包括产品特征和计量目标。 计量目标包括测量重叠的大目标和小目标。 一些较小的目标分布在较大目标之间的位置，而其他小目标则放置在与大目标相同的位置。 通过比较在相同位置使用小目标和大目标测量的值，可以校正使用所有小目标测量的参数值以获得更高的精度。 大型目标主要位于划线之内，而小目标则分布在产品区域内。

公开(公告)号：WO2012022584A1

公开(公告)日：2012-02-23

申请号：PCT/EP2011/062739

申请日：2011-07-25

Applicant: ASML NETHERLANDS B.V. ,  SMILDE, Hendrik ,  VAN DER SCHAAR, Maurits ,  BHATTACHARYYA, Kaustuve

Inventor： SMILDE, Hendrik ,  VAN DER SCHAAR, Maurits ,  BHATTACHARYYA, Kaustuve

IPC: G03F7/20

CPC classification number: G03F7/70683 ,  G03F1/44 ,  G03F7/70633

Abstract: A pattern from a patterning device is applied to a substrate. The applied pattern includes device functional areas and metrology target areas. Each metrology target area comprises a plurality of individual grating portions, which are used for diffraction based overlay measurements or other diffraction based measurements. The gratings are of the small target type, which is small than an illumination spot used in the metrology. Each grating has an aspect ratio substantially greater than 1, meaning that a length in a direction perpendicular to the grating lines which is substantially greater than a width of the grating. Total target area can be reduced without loss of performance in the diffraction based metrology. A composite target can comprise a plurality of individual grating portions of different overlay biases. Using integer aspect ratios such as 2:1 or 4:1, grating portions of different directions can be packed efficiently into rectangular composite target areas.

Abstract translation: 将来自图案形成装置的图案应用于基板。 应用模式包括设备功能区域和计量目标区域。 每个测量目标区域包括多个单独的光栅部分，其用于基于衍射的覆盖测量或其他基于衍射的测量。 光栅是小目标类型，小于计量中使用的照明点。 每个光栅具有基本上大于1的长宽比，这意味着垂直于光栅线的方向上的长度大致大于光栅的宽度。 可以减少总目标面积，而不会在基于衍射的计量学中失去性能。 复合目标可以包括不同覆盖偏移的多个单独光栅部分。 使用诸如2：1或4：1的整数长宽比，可以将不同方向的光栅部分有效地包装到矩形复合目标区域中。