Secondary Electron Energy Contrast of Localized Buried Charge in Metal-Insulator-Silicon Structures.

This paper presents a new method for creating and monitoring controlled localized negatively charged regions inside insulators with a scanning electron microscope (SEM). A localized buried charged region is created and observed close to the point where a high voltage primary beam (10 kV) strikes a metal-insulator-silicon specimen. The amount of buried charge within the insulator at any given moment can be dynamically monitored by detecting the appearance of a second peak in the secondary electron (SE) energy spectrum.

A high-brightness large-diameter graphene coated point cathode field emission electron source.

There have been several long-standing problems of cold field emission sources for electron microscopy and lithography that have prevented their widespread use, such as their inherent ultrahigh vacuum condition requirement (<10 torr), relatively poor current stability and rapid emission decay. This paper presents a cold field emission electron source which overcomes these problems based upon using a graphene-coated nickel point cathode. Preliminary experiments demonstrate that it provides stable emission for relatively large tip diameters (micron sizes), can operate in high vacuum conditions (>10 torr) and has an ultralow work function value of 1.

Voltage and Dopant Concentration Measurements of Semiconductors using a Band-Pass Toroidal Energy Analyzer Inside a Scanning Electron Microscope.

This paper presents experimental results obtained from a scanning electron microscope (SEM) second-order focusing toroidal electron energy analyzer attachment. The results demonstrate that the analyzer can be used to obtain high signal-to-noise voltage and dopant concentration measurements on semiconductors in the presence of different electric field conditions at the sample. The experimentally calculated relative error of measurement typically varies from 31 to 63, corresponding to secondary electron (SE) signal mean shifts of 9-18 mV.

Probing and analyzing buried interfaces of multifunctional oxides using a secondary electron energy analyzer.

A contactless method of probing and analyzing multifunctional oxide interfaces using an electron energy analyzer inside a scanning electron microscope is presented. High contrast experimental secondary electron analyzer signals are used to detect changes in the interface conductivity of a LaAlO3/SrTiO3 sample. Monte Carlo simulations of the primary beam/specimen interaction are carried out and correlated with the experimental results in order to help understand the role of the primary beam energy and adjust it to enhance contrast.