The EM-Tec ST1 STEM imaging holder facilitates STEM imaging of TEM samples in an SEM or FESEM. The EM-Tec ST1 STEM imaging holder uses the Everhart-Thornley SE detector in the SEM chamber. The TEM grid is placed in the STEM imaging holder and de holder is positioned under the electron beam (typically in de centre of the SEM stage). The TEM sample is scanned with the electron beam and the STEM image is formed by converting the transmitted electrons, which hit the platinum conversion plate, into secondary electrons. The secondary electrons (holding the STEM image information) are collected by the SE detector in the sample chamber. It is advised to use high accelerating voltages (25-30kV) and thin samples to increase the transmitted electron signal. The STEM imaging detector is provided with a black conductive plastic electron absorption sleeve which is placed between the polepiece and the EM-Tec ST1 STEM imaging holder. The sleeve absorps the secondary and backscattered electrons emitting from the sample surface.
Constructed from vacuum grade aluminium, brass TEM grid holder, platinum electron conversion plate and conductive plastic sleeve. Platinum is used for the conversation due to its high secondary electron signal, stability and corrosion resistance. The STEM imaging holder provides a genuine signal from the converted transmitted electrons, resulting in high contrast STEM imaging
The EM-Tec ST1 STEM imaging holder is a cost effective method to add STEM capabilities to your SEM for a fraction of the cost of a dedicated STEM holder and detector for your SEM. The STEM imaging holder image quality rivals that of a dedicated STEM detector system. The limiting factors are sample thickness and accelerating voltage of the SEM.