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Microstructures fabricated by use of focused ion beam (FIB) direct scanning is useful for microsystems. However, a new phenomenon was found recently by our experimental results. After the FIB bombardment in the defined area, the microstructures were formed under the competence between the ion sputtering induced surface roughening and surface diffusion induced surface smoothing. The process was called self-organized formation. The generated microstructures were characterized by atomic force microscope (AFM). The measured results show that the dimensions of the microstructures were changed with time. In other word, the measured results were different between the samples just processed and that one finished over one week, and the former with smaller dimensions than the latter. The reason maybe due to the thermal effect induced by the FIB bombardment. We called it a natural annealing. The fabricated microstructures were not in stable state due to the internal stress caused by ion sputtering and thermal diffusion. At initial state, it is in dynamic balance. After the natural annealing with several days, the dynamic balance is changed by the thermal diffusion which caused the dimensions of the microstructures varied continuously. In addition, the surface oxidation is also another factor.

A nanopore array with diameter of ~30 nm was fabricated by use of focused ion beam (FIB) scanning and thin film coating on Si(100). A thin film of SiO₂ with thickness of 200 nm (used as a sacrificial layer) was coated by physical evaporation deposition (PVD) first. Next, the thin films of poly-silicon with thickness of 50 nm were coated on double side of the substrate. A window with an area of 2 × 2 mm² was opened by reactive ion etching from bottom side and reached to the thin film of SiO₂. After that, a fine controlled FIB milling with bitmap function (milling according to a designed pattern in a defined area) was used to scan the area. Signal is obtained by a sensor inside the vacuum chamber collecting secondary electrons emitted from the sputtered material when the beam reach the layer of SiO₂. Stopping the milling process at this moment, the nanopore array was derived after removing the sacrificial layer by wet chemical etching. The nanopore arrays were characterized using transmission electron microscopy (TEM) after the FIB drilling.

A technique was investigated for the fabrication of triode-type carbon nanotube (CNT) field emitter arrays, where an integrated extraction gate was built between the nanotube cathode and the anode. The gate improves the control capability of emission currents. To fabricate the metal-gated CNT field emitter arrays, well ordered cells were generated by focused ion beam (FIB) milling of platinum (Pt) coated silicon (Si) substrate and then modified by chemical etching. Two types of catalyst elements iron (Fe) and nickel (Ni), were used for growing the CNTs inside the cells. The methods for depositing catalysts into the cells include spin coating sol–gel Fe, FIB induced decomposition of ferrocene and sputter coating pure Ni. CNT growth was carried out by a chemical vapor deposition (CVD) process. The results suggest that the CNTs grew from inside the cells where the catalysts were located. In comparison, the CNTs synthesized from the sol–gel Fe catalyst were straighter than those from ferrocene Fe and pure Ni. The density and orientation of the CNTs in each cell are directly related to the type and quantity of the catalysts and are also affected by the size of the cells.

Titanium nitride (TiN) thin films have low electrical resistivity, good chemical and metallurgical stability, and exceptional mechanical properties. As such, we are interested in exploring TiN for use as mold material for micro-and nano replication. Focused ion beam (FIB) technique was successfully used to fabricate sub-micron sized pattern on a TiN/Si(100) wafer. This mask-free fabrication technique takes advantage of the kinetic precision of FIB; the energy of ions used was 40 KeV. The width and depth of each trench in the TiN mold are 390 nm and 280 nm respectively.

Nowadays, nanogap-nanopore devices have attracted widely concerns for its potential application in the third generation DNA sequencing. However, an effective universal method to fabricate nanogap-nanopore device is still needed to overcome the low efficiency problem in fabrication technology. In this paper, wafer-lever Au nanogap-nanopore was fabricated by NEMS technology successfully. Suspended sandwich structure (SiN-Au nanowire-SiO₂, 100nm/20nm/200nm thick) was demonstrated, which can isolate Au nanowire and salt solution effectively. Moreover, this thin nano structure made Au nanogap-nanopore milling much easier with the help of focused ion beam (FIB) in a controllable way. Since the whole manufacture process was achieved in wafer-lever, this method made Au nanogap-nanopore in DNA sequencing more convenient.