Publication details
Strategies for Collection of Secondary Electrons in the SEM
| Authors | |
|---|---|
| Year of publication | 2007 |
| Type | Article in Periodical |
| MU Faculty or unit | |
| Citation | |
| Web | http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=1329500&fulltextType=PI&fileId=S1431927607080397 |
| Field | Electronics amd optoelectronics, electrotechnics |
| Keywords | collection efficiency, secondary electrons, ET detector, magnetic field |
| Description | The standard way of secondary electron (SE) detection in the scanning electron microscope (SEM) is to use the Everhart-Thornley (ET) detector. Only weak electrostatic field attracts low energy SEs. Let us call this system the standard detector. Although the ET detector has been around for more than fifty years, it remains the most frequently used type of detector in SEMs. Modern SEMs have improved their image resolution by so called immersion systems, allowing a strong magnetic field of the objective lens to penetrate into the specimen region. In that case, two ET detectors are usually used: one is located above the objective lens, and the other below it (upper and lower detector). The resulting contrast of the SE images depends on SE energy and on the angular sensitivity of detectors, which is a result of specific distributions of electrostatic and magnetic fields in the specimen region. |