公开(公告)号：US20200073254A1

公开(公告)日：2020-03-05

申请号：US16675674

申请日：2019-11-06

Applicant: ASML Netherlands B.V.

Inventor： Maurits VAN DER SCHAAR ,  Youping ZHANG ,  Hendrik Jan Hidde SMILDE ,  Anagnostis TSIATMAS ,  Adriaan Johan VAN LEEST ,  Alok VERMA ,  Thomas THEEUWES ,  Hugo Augustinus Joseph CRAMER ,  Paul Christiaan HINNEN

IPC: G03F7/20 ,  G01N21/47 ,  G01N21/95

Abstract: A substrate has first and second target structures formed thereon by a lithographic process. Each target structure has two-dimensional periodic structure formed in a single material layer on a substrate using first and second lithographic steps, wherein, in the first target structure, features defined in the second lithographic step are displaced relative to features defined in the first lithographic step by a first bias amount that is close to one half of a spatial period of the features formed in the first lithographic step, and, in the second target structure, features defined in the second lithographic step are displaced relative to features defined in the first lithographic step by a second bias amount close to one half of said spatial period and different to the first bias amount. An angle-resolved scatter spectrum of the first target structure and an angle-resolved scatter spectrum of the second target structure is obtained, and a measurement of a parameter of a lithographic process is derived from the measurements using asymmetry found in the scatter spectra of the first and second target structures.

公开(公告)号：US20190094712A1

公开(公告)日：2019-03-28

申请号：US16185062

申请日：2018-11-09

Applicant: ASML Netherlands B.V.

Inventor： Hendrik Jan Hidde SMILDE ,  Bastiaan Onne FAGGINGER AUER ,  Davit HARUTYUNYAN ,  Patrick WARNAAR

IPC: G03F7/20 ,  G03F9/00 ,  G01B9/04 ,  G01N21/88

CPC classification number: G03F7/70625 ,  G01B9/04 ,  G01B2210/56 ,  G01N2021/8822 ,  G03F7/70633 ,  G03F7/70641 ,  G03F9/7092

Abstract: In a dark-field metrology method using a small target, a characteristic of an image of the target, obtained using a single diffraction order, is determined by fitting a combination fit function to the measured image. The combination fit function includes terms selected to represent aspects of the physical sensor and the target. Some coefficients of the combination fit function are determined based on parameters of the measurement process and/or target. In an embodiment the combination fit function includes jinc functions representing the point spread function of a pupil stop in the imaging system.

公开(公告)号：US20160161864A1

公开(公告)日：2016-06-09

申请号：US14906896

申请日：2014-07-18

Applicant: ASML NETHERLANDS B.V.

Inventor： Scott Anderson MIDDLEBROOKS ,  Niels GEYPEN ,  Hendrik Jan Hidde SMILDE ,  Alexander STRAAIJER ,  Maurits VAN DER SCHAAR ,  Markus Gerardus Martinus Maria VAN KRAAIJ

IPC: G03F7/20

CPC classification number: G03F7/70633

Abstract: Disclosed is a method of measuring a parameter of a litho-graphic process, and associated inspection apparatus. The method comprises measuring at least two target structures on a substrate using a plurality of different illumination conditions, the target structures having deliberate overlay biases; to obtain for each target structure an asymmetry measurement representing an overall asymmetry that includes contributions due to (i) the deliberate overlay biases, (ii) an overlay error during forming of the target structure and (iii) any feature asymmetry. A regression analysis is performed on the asymmetry measurement data by fitting a linear regression model to a planar representation of asymmetry measurements for one target structure against asymmetry measurements for another target structure, the linear regression model not necessarily being fitted through an origin of the planar representation. The overlay error can then be determined from a gradient described by the linear regression model.

Abstract translation: 公开了一种测量光刻图形处理参数的方法和相关联的检查装置。 该方法包括使用多个不同的照明条件测量衬底上的至少两个目标结构，所述目标结构具有有意的覆盖偏移; 为每个目标结构获得表示总体不对称性的不对称测量，其包括由于（i）故意重叠偏差引起的贡献，（ii）在形成目标结构期间的覆盖误差，以及（iii）任何特征不对称性。 对不对称测量数据进行回归分析，通过将线性回归模型拟合到针对另一目标结构的不对称测量的一个目标结构的不对称测量的平面表示，线性回归模型不一定通过平面表示的原点拟合 。 然后可以从线性回归模型描述的梯度确定覆盖误差。

公开(公告)号：US20140139814A1

公开(公告)日：2014-05-22

申请号：US14149723

申请日：2014-01-07

Applicant: ASML Netherlands B.V.

Inventor： Hugo Augustinus Joseph CRAMER ,  Arie Jeffrey DEN BOEF ,  Henricus Johanne Lambertus MEGENS ,  Hendrik Jan Hidde SMILDE ,  Adrianus Johanne Hendrikus SCHELLEKENS ,  Michael KUBIS

IPC: G03F7/20 ,  G01N21/88

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 is 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，使用光刻工艺在基板上形成结构，该结构具有至少一个特征，该特征在印刷图案中具有不对称性 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。 第一图像使用非零阶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：US20200379359A1

公开(公告)日：2020-12-03

申请号：US16988766

申请日：2020-08-10

Applicant: ASML Netherlands B.V.

Inventor： Hendrik Jan Hidde SMILDE ,  Bastiaan Onne FAGGINGER AUER ,  Davit HARUTYUNYAN ,  Patrick WARNAAR

IPC: G03F7/20 ,  G01B9/04 ,  G03F9/00

Abstract: In a dark-field metrology method using a small target, a characteristic of an image of the target, obtained using a single diffraction order, is determined by fitting a combination fit function to the measured image. The combination fit function includes terms selected to represent aspects of the physical sensor and the target. Some coefficients of the combination fit function are determined based on parameters of the measurement process and/or target. In an embodiment the combination fit function includes jinc functions representing the point spread function of a pupil stop in the imaging system.

公开(公告)号：US20190049860A1

公开(公告)日：2019-02-14

申请号：US16159884

申请日：2018-10-15

Applicant: ASML Netherlands B.V.

Inventor： Scott Anderson MIDDLEBROOKS ,  Niels GEYPEN ,  Hendrik Jan Hidde SMILDE ,  Alexander STRAAIJER ,  Maurits VAN DER SCHAAR ,  Markus Gerardus Martinus Maria VAN KRAAIJ

IPC: G03F7/20

CPC classification number: G03F7/70633

Abstract: Disclosed is a method of measuring a parameter of a lithographic process, and associated inspection apparatus. The method comprises measuring at least two target structures on a substrate using a plurality of different illumination conditions, the target structures having deliberate overlay biases; to obtain for each target structure an asymmetry measurement representing an overall asymmetry that includes contributions due to (i) the deliberate overlay biases, (ii) an overlay error during forming of the target structure and (iii) any feature asymmetry. A regression analysis is performed on the asymmetry measurement data by fitting a linear regression model to a planar representation of asymmetry measurements for one target structure against asymmetry measurements for another target structure, the linear regression model not necessarily being fitted through an origin of the planar representation. The overlay error can then be determined from a gradient described by the linear regression model.

公开(公告)号：US20160334715A1

公开(公告)日：2016-11-17

申请号：US15115229

申请日：2014-12-30

Applicant: ASML NETHERLANDS B.V.

Inventor： Hendrik Jan Hidde SMILDE ,  Bastiann Onne FAGGINGER AUER ,  Davit HARUTYUNYAN

IPC: G03F7/20

CPC classification number: G03F7/70625 ,  G01B9/04 ,  G01B2210/56 ,  G01N2021/8822 ,  G03F7/70633 ,  G03F7/70641 ,  G03F9/7092

Abstract: In a dark-field metrology method using a small target, a characteristic of an image of the target, obtained using a single diffraction order, is determined by fitting a combination fit function to the measured image. The combination fit function includes terms selected to represent aspects of the physical sensor and the target. Some coefficients of the combination fit function are determined based on parameters of the measurement process and/or target. In an embodiment the combination fit function includes jinc functions representing the point spread function of a pupil stop in the imaging system.

Abstract translation: 在使用小目标的暗场测量方法中，通过将组合拟合函数拟合到测量图像来确定使用单个衍射级获得的目标图像的特性。 组合拟合功能包括用于表示物理传感器和目标的方面的术语。 基于测量过程和/或目标的参数来确定组合拟合函数的一些系数。 在一个实施例中，组合拟合功能包括表示成像系统中瞳孔停止点的点扩展函数的jinc函数。

公开(公告)号：US20160033877A1

公开(公告)日：2016-02-04

申请号：US14824696

申请日：2015-08-12

Applicant: ASML Netherlands B.V.

Inventor： Hendrik Jan Hidde SMILDE ,  Arno Jan Bleeker ,  Willem Marie Julia Marcel Coene ,  Patrick Warnaar ,  Michael Kubis

IPC: G03F7/20 ,  G06N99/00

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

Abstract: Methods are disclosed for measuring target structures formed by a lithographic process on a substrate. A grating structure within the target is smaller than an illumination spot and field of view of a measurement optical system. The optical system has a first branch leading to a pupil plane imaging sensor and a second branch leading to a substrate plane imaging sensor. A spatial light modulator 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上的光刻工艺形成的目标结构的方法。 目标内的光栅结构小于测量光学系统的照明点和视场。 光学系统具有通向光瞳平面成像传感器的第一分支和通向基板平面成像传感器的第二分支。 空间光调制器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：US20150346116A1

公开(公告)日：2015-12-03

申请号：US14825751

申请日：2015-08-13

Applicant: ASML Netherlands B.V.

Inventor： Hendrik Jan Hidde SMILDE ,  Omer Abubaker Omer ADAM

IPC: G01N21/956 ,  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）光刻工艺中的覆盖误差（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。