公开(公告)号：US20210375651A1

公开(公告)日：2021-12-02

申请号：US17246060

申请日：2021-04-30

Applicant: KLA Corporation

Inventor： Song Wu ,  Tianrong Zhan ,  Lie-Quan Lee

IPC: H01L21/67 ,  G01N21/95 ,  G05B19/418

Abstract: Methods and systems for calibrating metrology tool offset values to match measurement results across a fleet of metrology tools are presented herein. The calibration of offset values is based on measurements of inline, production wafers and does not require the use of specially fabricated and characterized quality control (QC) wafers. In this manner, the entire process flow to calibrate metrology tool offset values is automated and fully integrated within a high volume semiconductor fabrication process flow. In a further aspect, the implementation of a new offset value is regulated by one or more predetermined control limit values. In another further aspect, the measured values of a parameter of interest are adjusted to compensate for the effects of measurement time on the wafer under measurement.

公开(公告)号：US20240102941A1

公开(公告)日：2024-03-28

申请号：US18244749

申请日：2023-09-11

Applicant: KLA Corporation

Inventor： Brian C. Lin ,  David Wu ,  Song Wu ,  Tianrong Zhan ,  Emily Chiu ,  Andrew Lagodzinski

IPC: G01N21/95 ,  G01N21/31 ,  G01N21/47

CPC classification number: G01N21/9505 ,  G01N21/31 ,  G01N21/4738 ,  G01N2201/127

Abstract: Methods and systems for calibrating simulated measurement signals generated by a parametric measurement model are described herein. Regression on real measurement signals is performed using a parametric model. The residual fitting error between the real measurement signals and simulated measurement signals generated by the parametric model characterizes the error of the parametric model at each set of estimated values of the one or more floating parameters. Simulated measurement signals are generated by the parametric model at specified values of the floating parameters. A residual fitting error associated with the simulated measurement signals generated at the specified values of the floating parameters is derived from the residual fitting errors calculated by the regression on the real measurement signals. The simulated measurement signals are calibrated by adding the residual fitting error to the uncalibrated, simulated measurement signals. The calibrated, simulated measurement signals improve the accuracy of measurements and measurement recipe development.

公开(公告)号：US20230063102A1

公开(公告)日：2023-03-02

申请号：US17506201

申请日：2021-10-20

Applicant: KLA Corporation

Inventor： Brian C. Lin ,  Jiqiang Li ,  Song Wu ,  Tianrong Zhan ,  Andrew Lagodzinski

IPC: G01N21/95

Abstract: Methods and systems for selecting measurement locations on a wafer for subsequent detailed measurements employed to characterize the entire wafer are described herein. High throughput measurements are performed at a relatively large number of measurement sites on a wafer. The measurement signals are transformed to a new mathematical basis and reduced to a significantly smaller dimension in the new basis. A set of representative measurement sites is selected based on analyzing variation of the high throughput measurement signals. In some embodiments, the spectra are subdivided into a set of different groups. The spectra are grouped together to minimize variance within each group. Furthermore, a die location is selected that is representative of the variance exhibited by the die in each group. A spectrum of a measurement site and corresponding wafer location is selected to correspond most closely to the center point of each cluster.

公开(公告)号：US12085515B2

公开(公告)日：2024-09-10

申请号：US17506201

申请日：2021-10-20

Applicant: KLA Corporation

Inventor： Brian C. Lin ,  Jiqiang Li ,  Song Wu ,  Tianrong Zhan ,  Andrew Lagodzinski

IPC: G01N21/95

CPC classification number: G01N21/9501

Abstract: Methods and systems for selecting measurement locations on a wafer for subsequent detailed measurements employed to characterize the entire wafer are described herein. High throughput measurements are performed at a relatively large number of measurement sites on a wafer. The measurement signals are transformed to a new mathematical basis and reduced to a significantly smaller dimension in the new basis. A set of representative measurement sites is selected based on analyzing variation of the high throughput measurement signals. In some embodiments, the spectra are subdivided into a set of different groups. The spectra are grouped together to minimize variance within each group. Furthermore, a die location is selected that is representative of the variance exhibited by the die in each group. A spectrum of a measurement site and corresponding wafer location is selected to correspond most closely to the center point of each cluster.