Perimeter trench formation and delineation etch delayering

    公开(公告)号:US11257683B2

    公开(公告)日:2022-02-22

    申请号:US16903922

    申请日:2020-06-17

    Applicant: FEI Company

    Abstract: Apparatus and methods are disclosed for sample preparation, suitable for online or offline use with multilayer samples. Ion beam technology is leveraged to provide rapid, accurate delayering with etch stops at a succession of target layers. In one aspect, a trench is milled around a region of interest (ROI), and a conductive coating is developed on an inner sidewall. Thereby, reliable conducting paths are formed between intermediate layers within the ROI and a base layer, and stray current paths extending outside the ROI are eliminated, providing better quality etch progress monitoring, during subsequent etching, from body or scattered currents. Ion beam assisted gas etching provides rapid delayering with etch stops at target polysilicon layers. Uniform etching at deep layers can be achieved. Variations and results are disclosed.

    PERIMETER TRENCH FORMATION AND DELINEATION ETCH DELAYERING

    公开(公告)号:US20220139722A1

    公开(公告)日:2022-05-05

    申请号:US17578903

    申请日:2022-01-19

    Applicant: FEI Company

    Abstract: Apparatus and methods are disclosed for sample preparation, suitable for online or offline use with multilayer samples. Ion beam technology is leveraged to provide rapid, accurate delayering with etch stops at a succession of target layers. In one aspect, a trench is milled around a region of interest (ROI), and a conductive coating is developed on an inner sidewall. Thereby, reliable conducting paths are formed between intermediate layers within the ROI and a base layer, and stray current paths extending outside the ROI are eliminated, providing better quality etch progress monitoring, during subsequent etching, from body or scattered currents. Ion beam assisted gas etching provides rapid delayering with etch stops at target polysilicon layers. Uniform etching at deep layers can be achieved. Variations and results are disclosed.

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