Transmission Electron Microscopy (TEM) is an analytical technique that
relays on forward scattering of an electron beam to form images,
diffraction patterns, and spectra of electron energy loss (EELS) and
X-Ray energy (EDS).
TEM can achieve resolution on the order of <0.22nm, hence allowing imaging of atomic column arrangements. It also provides means to detect and identify presence of atomic species in small volumes of specimens, as low as 1nm in diameter. As such, its applications range from measurements of thickness of thin films, to characterization of inclusions, defects, and precipitates through composition analysis with GIF-EELS and X-EDS. EELS is especially suitable for detecting low-Z elements and transition metals. Moreover, TEM can visualize crystalline defects through strain-contrast formation allowing characterization of microstructure of materials from nano- through micro-scale.
In order to achieve the highest quality image, the sample must be thinned down to less than 100nm. Consequently, TEM requires an intensive and exacting process of sample preparation. Multiple techniques are used in our laboratory for TEM sample preparation.
Traditional mechanical polishing methods combined with ion milling are suitable for bulk and blanket-wafer samples. For the highest degree of accuracy in specific area preparation of nano-devices, such as novel transistors, Focused Ion Beam (FIB) milling is employed. It allows the sample to be viewed by secondary electron imaging (SEM) while thinning excess material to electron transparency using Ga+ beams.
TEM can achieve resolution on the order of <0.22nm, hence allowing imaging of atomic column arrangements. It also provides means to detect and identify presence of atomic species in small volumes of specimens, as low as 1nm in diameter. As such, its applications range from measurements of thickness of thin films, to characterization of inclusions, defects, and precipitates through composition analysis with GIF-EELS and X-EDS. EELS is especially suitable for detecting low-Z elements and transition metals. Moreover, TEM can visualize crystalline defects through strain-contrast formation allowing characterization of microstructure of materials from nano- through micro-scale.
In order to achieve the highest quality image, the sample must be thinned down to less than 100nm. Consequently, TEM requires an intensive and exacting process of sample preparation. Multiple techniques are used in our laboratory for TEM sample preparation.
Traditional mechanical polishing methods combined with ion milling are suitable for bulk and blanket-wafer samples. For the highest degree of accuracy in specific area preparation of nano-devices, such as novel transistors, Focused Ion Beam (FIB) milling is employed. It allows the sample to be viewed by secondary electron imaging (SEM) while thinning excess material to electron transparency using Ga+ beams.