Processing of Endpoint Information from HAR Vias PBS&T Processing of Endpoint Information from HAR Vias Valery Ray vray@partbeamsystech.com EFUG 2006, Wuppertal, Germany

Outline Mechanism of HAR Endpoint Detection Distribution of Endpoint Information Example of Spatial Filtering Summary 5/9/2019 EFUG 2006, Wuppertal, Germany 2

HAR Endpoint Mechanism: Negative Wall Charge ILD Metal Line Negative charge on sidewalls Based on assumption of negative wall charging induced by FIB within HAR via. Proposed by T. Lindquist ISTFA 2004 5/9/2019 EFUG 2006, Wuppertal, Germany 3

HAR Endpoint Mechanism: Metal Redeposition Based on assumption of re-deposition of metal from conductor on walls of HAR via Proposed by V. Ray ISTFA 2005 Sidewall redeposit ILD ILD Metal Line 5/9/2019 EFUG 2006, Wuppertal, Germany 4

Observation of Endpoint Details Endpoint image of via with 10:1 aspect ratio FOV 1µm IBeam 5 pA Spatial distribution of information is evident Spatial Filtering Window Excluded Area Integration Window 5/9/2019 EFUG 2006, Wuppertal, Germany 5

Integration and Filtering Spatially Filtered Endpoint S/N Improvement by Factor ~2 Integrated Endpoint 5/9/2019 EFUG 2006, Wuppertal, Germany 6

Summary HAR Endpoint Information is available primarily on periphery of the via. Spatial filtering excludes ~ 80% of dwell points in center of the via from integration. Use of spatial filtering improves S/N of endpoint detection graph by factor ~ 2. Technique is equally applicable to sample current and secondary electron endpoint detection. 5/9/2019 EFUG 2006, Wuppertal, Germany 7

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