Beam Deceleration Technology

Beam deceleration technology (BDT) is intended for the highest resolution at low electron beam energies.
BDT includes a system for negative voltage biasing of the sample stage and an In-beam detector that works either as SE detector in the beam deceleration mode (BDM) or BSE detector in the standard mode.

BDT in the new immersion 2016 models equipped with the new Triglav™ UHR SEM column consists of the BDM and high-performance In-Beam detectors for simultaneous SE and BSE signal detection in this mode.

In the BDM, the energy of the electrons in the beam is decreased before they impact the surface of the specimen by means of a negative bias voltage which is applied to the sample stage.  Ultra-low landing energies down to 50 eV (or 0 eV in manual control) are achievable. BDM enhances the performance of the electron column by reducing optical aberrations, thus allowing small spot sizes and high-resolution imaging at low energies. 

Low electron energies are advantageous for reducing charging effects in non-conductive samples and beam-sensitive specimens such as transistor layers in cross-sectioned integrated circuits for failure analysis, low-k dielectric materials and photoresists. BDM is especially suited for imaging biological specimens in their uncoated state at ultra-low beam energies without damaging the samples. In this mode, ultimate resolution at low landing energies is achieved for maximum surface sensitivity and outstanding topographical and material contrast.
Beam Deceleration Technology
Tin balls on carbon imaged in the BDM at 1 keV using the SE (BDM) detector (top) providing topographic information with typical edge effect and, using BSE (BDM) detector (bottom) giving a compositional information.