3D strain measurement in electronic devices using through-focal annular dark-field imaging.

Spherical aberration correction in high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) allows us to form an electron probe with reduced depth of field. Using through-focal HAADF imaging, we experimentally demonstrated 3D strain measurement in a strained-channel transistor. The strain field distribution in the channel region was obtained by scanning an electron beam over a plan-view specimen.

Characterization of the charging effect in a ZrO2 sintered body by Ga ion beam irradiation.

The charging effect in a ZrO2 sintered body was investigated by using scanning ion microscope (SIM) images. In this study, we report interesting features caused by the charging effect in the ZrO2 sintered body during the Ga ion beam irradiation: a bright contrast with a distorted net shape appears around the positively charged specimen. From this feature in the SIM image, it is clarified that the Ga ion beam is strongly deflected and the wide area of the internal parts of the focused ion beam machine is irradiated by the Ga ion beam, depending on the extent to which the specimen is charged.

Electron holography study for two-dimensional dopant profile measurement with specimens prepared by backside ion milling.

The visualization of two-dimensional dopant profiles and the quantitative analysis of the built-in potential across the p-n junction, DeltaV(p-n), by electron holography were carried out with specimens prepared from the backside ion milling method combined with the focused ion beam technique. It was possible to obtain dopant profiling of the large field of view with low surface damage and gradually changed thickness. From the quantitative analysis using the phase information of electron holography and the thickness information of electron energy-loss spectroscopy, DeltaV(p-n) was estimated to be about 0.

Measurement of electric potential distributions around FEG-emitters by electron holography.

An evaluation technique for field emission guns (FEG-emitters) was established by using electron holography. For performing electron holography under an applied voltage, a specimen holder with the capabilities of three-directional motion as well as voltage application was developed. An unused Schottky emitter and a used emitter that had failed after operating for about 10,000 h were selected for this study.

Direct observation of field emission in a single TaSi2 nanowire.

The electric potential change in a single TaSi2 nanowire during field emission was visualized by means of electron holography. During the field emission, the interference fringes of the electron hologram were blurred locally between the TaSi2 nanowire and anode. This phenomenon was interpreted as being due to a change in the electric potential of approximately 1 V in the TaSi2 nanowire after each ballistic emission.

Electron holography on dynamic motion of secondary electrons around sciatic nerve tissues.

By means of electron holographic visualization of detailed electric potential distribution around sciatic nerve tissues coated with C and OsO(4), we show that the steady state of these specimens subjected to intense charging with electron irradiation is accompanied with a dynamic motion of collective secondary electrons; the secondary electrons emitted from the coated specimens revolve around the positively charged specimens forming stationary orbits. Further, this study clarified the possibility of the direct visualization of a part of the orbits of the collective secondary electrons without disturbing their motions.

Analytical electron microscopy study of nanometre-scale oxide formed in contact-hole-bottom Si surfaces.

Nanometre-scale interfacial oxides formed in contact-hole-bottom Si surfaces were investigated by analytical electron microscopy coupled with a field-emission transmission electron microscope. The results showed that the chemical state of the residual oxide formed during reactive-ion etching was mostly changed from the suboxide of Si2+ or Si3+ to the oxide of Si4+ by the following light-etch treatment. Consequently, the process of removing the residual oxide by light-etch treatment was improved and it contributed to the accomplishment of lower contact resistance.