公开(公告)号：US20200025554A1

公开(公告)日：2020-01-23

申请号：US15362741

申请日：2016-11-28

Applicant: KLA-Tencor Corporation

Inventor： Antonio A. Gellineau ,  Alexander Kuznetsov ,  John J. Hench ,  Andrei V. Shchegrov ,  Stilian Ivanov Pandev

IPC: G01B11/02

Abstract: A system, method and computer program product are provided for selecting signals to be measured utilizing a metrology tool that optimizes the precision of the measurement. The technique includes the steps of simulating a set of signals for measuring one or more parameters of a metrology target. A normalized Jacobian matrix corresponding to the set of signals is generated, a subset of signals in the simulated set of signals is selected that optimizes a performance metric associated with measuring the one or more parameters of the metrology target based on the normalized Jacobian matrix, and a metrology tool is utilized to collect a measurement for each signal in the subset of signals for the metrology target. For a given number of signals collected by the metrology tool, this technique optimizes the precision of such measurements over conventional techniques that collect signals uniformly distributed over a range of process parameters.

公开(公告)号：US10354929B2

公开(公告)日：2019-07-16

申请号：US13887524

申请日：2013-05-06

Applicant: KLA-Tencor Corporation

Inventor： Stilian Ivanov Pandev

IPC: H01L21/66 ,  G01B11/24

Abstract: An optimized measurement recipe is determined by reducing the set of measurement technologies and ranges of machine parameters required to achieve a satisfactory measurement result. The reduction in the set of measurement technologies and ranges of machine parameters is based on available process variation information and spectral sensitivity information associated with an initial measurement model. The process variation information and spectral sensitivity information are used to determine a second measurement model having fewer floating parameters and less correlation among parameters. Subsequent measurement analysis is performed using the second, constrained model and a set of measurement data corresponding to a reduced set of measurement technologies and ranges of machine parameters. The results of the subsequent measurement analysis are compared with reference measurement results to determine if a difference between the estimated parameter values and the parameter values derived from the reference measurement is within a predetermined threshold.

公开(公告)号：US10295342B2

公开(公告)日：2019-05-21

申请号：US15236334

申请日：2016-08-12

Applicant: KLA-Tencor Corporation

Inventor： Stilian Ivanov Pandev ,  Dzmitry Sanko

IPC: G01B21/04

Abstract: A system, method and computer program product are provided for calibrating metrology tools. One or more design-of-experiments wafers is received for calibrating a metrology tool. A set of signals is collected by measuring the one or more wafers utilizing the metrology tool. A first transformation is determined to convert the set of signals to components, and a second transformation is determined to convert a set of reference signals to reference components. The set of reference signals is collected by measuring the one or more wafers utilizing a well-calibrated reference tool. A model is trained based on the reference components that maps the components to converted components, and the model, first transformation, and second transformation are stored in a memory associated with the metrology tool.

公开(公告)号：US10151986B2

公开(公告)日：2018-12-11

申请号：US14790793

申请日：2015-07-02

Applicant: KLA-Tencor Corporation

Inventor： Andrei V. Shchegrov ,  Thaddeus Gerard Dziura ,  Stilian Ivanov Pandev ,  Leonid Poslavsky

IPC: G03F7/20 ,  H01L21/66

Abstract: Methods and systems for estimating values of parameters of interest of actual device structures based on optical measurements of nearby metrology targets are presented herein. High throughput, inline metrology techniques are employed to measure metrology targets located near actual device structures. Measurement data collected from the metrology targets is provided to a trained signal response metrology (SRM) model. The trained SRM model estimates the value of one or more parameters of interest of the actual device structure based on the measurements of the metrology target. The SRM model is trained to establish a functional relationship between actual device parameters measured by a reference metrology system and corresponding optical measurements of at least one nearby metrology target. In a further aspect, the trained SRM is employed to determine corrections of process parameters to bring measured device parameter values within specification.

公开(公告)号：US10139352B2

公开(公告)日：2018-11-27

申请号：US14882370

申请日：2015-10-13

Applicant: KLA-Tencor Corporation

Inventor： Stilian Ivanov Pandev ,  Wei Lu ,  Andrei V. Shchegrov ,  Pablo Rovira ,  Jonathan M. Madsen

IPC: G01N21/93 ,  G01N21/956

Abstract: Methods and systems for measuring metrology targets smaller than the illumination spot size employed to perform the measurement are described herein. Collected measurement signals contaminated with information from structures surrounding the target area are reconstructed to eliminate the contamination. In some examples, measurement signals associated one or more small targets and one or more large targets located in close proximity to one another are used to train a signal reconstruction model. The model is subsequently used to reconstruct measurement signals from other small targets. In some other examples, multiple measurements of a small target at different locations within the target are de-convolved to estimate target area intensity. Reconstructed measurement signals are determined by a convolution of the illumination spot profile and the target area intensity. In a further aspect, the reconstructed signals are used to estimate values of parameters of interest associated with the measured structures.

公开(公告)号：US10107765B2

公开(公告)日：2018-10-23

申请号：US15671661

申请日：2017-08-08

Applicant: KLA-Tencor Corporation

Inventor： Noam Sapiens ,  Andrei V. Shchegrov ,  Stilian Ivanov Pandev

IPC: G01N21/93 ,  G01N21/95 ,  G01N21/956 ,  G01N21/47

Abstract: In one embodiment, apparatus and methods for determining a parameter of a target are disclosed. A target having an imaging structure and a scatterometry structure is provided. An image of the imaging structure is obtained with an imaging channel of a metrology tool. A scatterometry signal is also obtained from the scatterometry structure with a scatterometry channel of the metrology tool. At least one parameter, such as overlay error, of the target is determined based on both the image and the scatterometry signal.

公开(公告)号：US20180252514A1

公开(公告)日：2018-09-06

申请号：US15861938

申请日：2018-01-04

Applicant: KLA-Tencor Corporation

Inventor： Stilian Ivanov Pandev ,  Andrei V. Shchegrov ,  Wei Lu

IPC: G01B11/14 ,  G06F7/48 ,  G06T7/60 ,  G03F7/20

Abstract: Methods and systems for robust overlay error measurement based on a trained measurement model are described herein. The measurement model is trained from raw scatterometry data collected from Design of Experiments (DOE) wafers by a scatterometry based overlay metrology system. Each measurement site includes one or more metrology targets fabricated with programmed overlay variations and known process variations. Each measurement site is measured with known metrology system variations. In this manner, the measurement model is trained to separate actual overlay from process variations and metrology system variations which affect the overlay measurement. As a result, an estimate of actual overlay by the trained measurement model is robust to process variations and metrology system variations. The measurement model is trained based on scatterometry data collected from the same metrology system used to perform measurements. Thus, the measurement model is not sensitive to systematic errors, aysmmetries, etc.

公开(公告)号：US10030965B2

公开(公告)日：2018-07-24

申请号：US15148116

申请日：2016-05-06

Applicant: KLA-Tencor Corporation

Inventor： Stilian Ivanov Pandev ,  Sanjay Kapasi ,  Mark D. Smith ,  Ady Levy

IPC: G01B11/00 ,  H01L21/66

Abstract: Methods and systems for monitoring parameters characterizing a set of hot spot structures fabricated at different locations on a semiconductor wafer are presented herein. The hot spot structures are device structures that exhibit sensitivity to process variations and give rise to limitations on permissible process variations that must be enforced to prevent device failures and low yield. A trained hot spot measurement model is employed to receive measurement data generated by one or more metrology systems at one or more metrology targets and directly determine values of one or more hot spot parameters. The hot spot measurement model is trained to establish a functional relationship between one or more characteristics of a hot spot structure under consideration and corresponding measurement data associated with measurements of at least one metrology target on the same wafer. A fabrication process parameter is adjusted based on the value of a measured hot spot parameter.

公开(公告)号：US09784690B2

公开(公告)日：2017-10-10

申请号：US14708058

申请日：2015-05-08

Applicant: KLA-Tencor Corporation

Inventor： Noam Sapiens ,  Andrei V. Shchegrov ,  Stilian Ivanov Pandev

IPC: G01N21/93 ,  G01N21/95 ,  G01N21/956 ,  G01N21/47

CPC classification number: G01N21/93 ,  G01B2210/56 ,  G01N21/4788 ,  G01N21/9501 ,  G01N21/95607 ,  G01N2201/06113 ,  G01N2201/062 ,  G01N2201/10 ,  G01N2201/1296

Abstract: In one embodiment, apparatus and methods for determining a parameter of a target are disclosed. A target having an imaging structure and a scatterometry structure is provided. An image of the imaging structure is obtained with an imaging channel of a metrology tool. A scatterometry signal is also obtained from the scatterometry structure with a scatterometry channel of the metrology tool. At least one parameter, such as overlay error, of the target is determined based on both the image and the scatterometry signal.

公开(公告)号：US09518916B1

公开(公告)日：2016-12-13

申请号：US14511810

申请日：2014-10-10

Applicant: KLA-Tencor Corporation

Inventor： Stilian Ivanov Pandev ,  Alexander Kuznetsov ,  Gregory R. Brady ,  Andrei V. Shchegrov ,  Noam Sapiens ,  John J. Hench

IPC: G01N21/25 ,  G01N21/84

CPC classification number: G06T7/0004 ,  G01B2210/56 ,  G01N21/211 ,  G01N21/255 ,  G01N21/84 ,  G01N21/8422 ,  G01N2201/06113 ,  G03F7/70625 ,  G03F7/70633 ,  G06T7/60 ,  G06T2207/10004 ,  G06T2207/30148

Abstract: Disclosed are apparatus and methods for determining a structure or process parameter value of a target of interest on a semiconductor wafer. A plurality of collection patterns are defined for a spatial light beam controller positioned at a pupil image plane of a metrology tool. For each collection pattern, a signal is collected from a sensor of the metrology tool, and each collected signal represents a combination of a plurality of signals that the spatial light beam controller samples, using each collection pattern, from a pupil image of the target of interest. The collection patterns are selected so that the pupil image is reconstructable based on the collection patterns and their corresponding collection signals. The collected signal for each of the collection patterns is analyzed to determine a structure or process parameter value for the target of interest.

Abstract translation: 公开了用于确定半导体晶片上的感兴趣的目标的结构或过程参数值的装置和方法。 为位于计量工具的光瞳像平面处的空间光束控制器定义了多个收集图案。 对于每个收集图案，从计量工具的传感器收集信号，并且每个收集的信号表示多个信号的组合，空间光束控制器使用每个收集模式从目标的瞳孔图像 利益。 选择收集图案，使得基于收集图案及其对应的收集信号可以重建瞳孔图像。 分析每个收集模式的收集信号，以确定感兴趣的目标的结构或过程参数值。