학술논문

Continuous-Time Modeling and Analysis of Particle Beam Metrology
Document Type
Periodical
Source
IEEE Journal on Selected Areas in Information Theory IEEE J. Sel. Areas Inf. Theory Selected Areas in Information Theory, IEEE Journal on. 4:61-74 2023
Subject
Communication, Networking and Broadcast Technologies
Noise measurement
Particle beams
Electron microscopy
Poisson equations
Particle beam optics
Metrology
Binary hypothesis testing
electron microscopy
Fisher information
helium ion microscopy
Kullback–Leibler divergence
Neyman Type A distribution
Poisson processes
truncated Poisson distribution
zero-inflated Poisson distribution
Language
ISSN
2641-8770
Abstract
Particle beam microscopy (PBM) performs nanoscale imaging by pixelwise capture of scalar values representing noisy measurements of the response from secondary electrons (SEs) integrated over a dwell time. Extended to metrology, goals include estimating SE yield at each pixel and detecting differences in SE yield across pixels; obstacles include shot noise in the particle source as well as lack of knowledge of and variability in the instrument response to single SEs. A recently introduced time-resolved measurement paradigm promises mitigation of source shot noise, but its analysis and development have been largely limited to estimation problems under an idealization in which SE bursts are directly and perfectly counted. Here, analyses are extended to error exponents in feature detection problems and to degraded measurements that are representative of actual instrument behavior for estimation problems. For estimation from idealized SE counts, insights on existing estimators and a superior estimator are also provided. For estimation in a realistic PBM imaging scenario, extensions to the idealized model are introduced, methods for model parameter extraction are discussed, and large improvements from time-resolved data are presented.