Methods and systems for acquiring electron backscatter diffraction patterns

A method for imaging a sample, comprising:

• repetitively scanning a region of interest (ROI) of the sample by directing a charged particle beam towards multiple impact points of the ROI and detecting particles scattered from the multiple impact points;
• during the repetitive scan, calculating a signal quality of each impact point of the multiple impact points, and updating a signal quality of the ROI based on the signal quality of each impact point after each single scan of the ROI, wherein the signal quality of a particular impact point indicates an accuracy for extracting structural information based on the detected particles scattered from the impact point;
• terminating the repetitive scan responsive to the signal quality of the ROI higher than a threshold signal quality;
• forming an electron backscattered diffraction (EBSD) pattern for each impact point of the multiple impact points based on all of the detected particles scattered from the impact point during the repetitive scan;
• and
• forming a structural image of the ROI based on the EBSD pattern.

A system for imaging a sample, comprising:

• a charged particle source for generating a charged particle beam towards a sample;
• a detector for detecting scattered particles from the sample;
• and
• a controller with computer readable instructions stored in a non-transitory medium, configured to:
• perform a first scan by directing a charged particle beam towards multiple impact points within a ROI, and detecting particles scattered from each impact point of the multiple impact points;
• calculate a signal quality of each impact point of the multiple impact points based on the detected particles scattered from the impact point, wherein the signal quality of the impact point indicates an accuracy for extracting structural information;
• calculate a signal quality of the ROI based on the signal quality of each impact point, wherein the signal quality of the ROI is lower than a threshold signal quality;
• perform a second scan by directing the charged particle beam towards one or more of the multiple impact points within the ROI after calculating the signal quality of the ROI, and detecting particles scattered from the one or more of the multiple impact points within the ROI;
• form an electron backscattered diffraction (EBSD) pattern for each impact point of the multiple impact points based on the detected particles scattered from the impact point during the first scan and the second scan;
• and
• form a structural image of the ROI based on the EBSD pattern.