FIB Etching Research Articles

Fabrication of a sidewall reflective optical switch by using FIB etching

Fabrication of a sidewall reflective optical switch by using FIB etching

Solid-State Nanopores Used for the Detection of DNA Molecules

Solid-state nanopore is crucial in dection of DNA molescules. DNA is made up of two antiparallel strands of polynucleotides. They are joined together by hydrogen bonds between complementary base pairs. The DNA structures are essential for the ability of genetic carrier to control gene expression, promote DNA recombination, and enhance mutagenesis. There are many ways to do DNA testing. Among these methods, nanopore have relatively small size which allows single-molecule detection. It is also less expensive. There are two kinds of nanopores, which are solid-state nanopore and biological nanopore. Solid state nanopore has better capacity to be incorporated into systems and arrays. The channel length and diameter of it can be controlled easily. In addition, its surface properties are also tunable. Therefore, this essay discussed concerning with the different types of nanopore technology: FEB, FIB and wet etching. The mechanism of nanopore was also explained. The existence of nanopores is conducive to a series of research on genes, pharmaceuticals, biology and so on.

3-D Analysis of a Copper Flip-Chip Interconnection Using FIB-SEM Slice and View

Abstract A detailed analysis based on FIB etching and SEM image capture was conducted on a flip-chip solder joint deep inside a tablet PC. 3D views reconstructed from SEM images show what appears to be a copper pillar with a solder cap connected to a copper trace on the substrate. The investigators believe the joint was formed by thermal compression bonding with a preapplied underfill. The analysis also revealed the presence of voids and intermetallic compounds along with signs of filler entrapment.

Nanometer scale patterning of GaN using nanoimprint lithography and Inductively Coupled Plasma etching

In this paper results on GaN patterning using nanoimprint technology are presented. Direct method of stamp fabrication based on FIB etching was used. Stamp with critical dimensions of 50nm was achieved. Two kinds of polymer materials were used for master stamp replication. Influence of etching parameters using chlorine based plasma on GaN etch rate and surface roughness was discussed. Triple mask consisting of TU2 resist, Cr and SiO2 used for NIL-generated pattern transfer into GaN allowed successful patterning.

Wavelength Trimming of Micro-Machined VCSELs

We demonstrate the wavelength trimming of MEMS VCSELs by etching a cantilever-shaped top mirror using FIB etching. The proposed technique can be used for the post-process precise wavelength allocation of athermal MEMS VCSELs. The modeling and experimental results on 850nm MEMS VCSELs are presented. The results show a possibility of realizing both red-shift and blue-shift wavelength changes by choosing the etching area of the cantilever.

Imaging of soft and hard materials using a Boersch phase plate in a transmission electron microscope

Using two levels of electron beam lithography, vapor phase deposition techniques, and FIB etching, we have fabricated an electrostatic Boersch phase plate for contrast enhancement of weak phase objects in a transmission electron microscope. The phase plate has suitable dimensions for the imaging of small biological samples without compromising the high-resolution capabilities of the microscope. A micro-structured electrode allows for phase tuning of the unscattered electron beam, which enables the recording of contrast enhanced in-focus images and in-line holograms. We have demonstrated experimentally that our phase plate improves the contrast of carbon nanotubes while maintaining high-resolution imaging performance, which is demonstrated for the case of an AlGaAs heterostructure. The development opens a new way to study interfaces between soft and hard materials.

Fabrication of Micro-Fluid-Channel Structures by Focused Ion Beam Techniques

AbstractOne of the new applications of focused Ga ion beam (Ga FIB) techniques to fabricate micro fluid channels on plate glass was demonstrated. After discussing features of the FIB etched patterns, narrow channel or Y-shaped channels were fabricated by FIB etching on a patterned plate glass which was prepared by photo-lithography and wet etching processes. Micro fluid devices were then constructed using polydimethylsiloxane (PDMS) sheet and silicone rubber tubes and the water (or ink) flow in the devices was observed under a microscope using a syringe pump. Although no discussion based on fluid mechanics has done at present, the present results indicate a possibility of applying FIB techniques to fabricate micro fluid devices which can be used in bio- and/or chemical-related fields.

Patterning and characterization of 2D photonic crystals fabricated by focused ion beametching of multilayer membranes

We report the modelling and characterization of 2D photonic crystals that we havesuccessfully implemented using a well adapted technical process: focused ion beam etchingof multilayer membranes. Devices have been dimensioned to operate as polarizing beamsplitters at telecommunication wavelengths. Modelling the experimental observations hasallowed us to characterize FIB etching performances and to propose further technologicalimprovements.

The fabrication of GaN‐based optical cavity mirrors by focused ion beam milling

The study of focused Ga ion beam milling for making GaN-based cavity mirrors is presented. The FIB etching rate of GaN was found to be in the rang of 0.6 μm3/nC – 0.43 μm3/nC. Three kinds of mirrors including polishing mirror, tilt mirror and nitride/air distributed Bragg reflection (DBR) mirror were fabricated. In particular, by using the transfer matrix method, the dependences of reflectivity and tolerance on the DBR Bragg order combination, number of DBR pair and nitride fill factor were calculated. To take trade-off between high reflectivity and enough tolerance, the combination of 3rd Bragg order of air gap and 5th Bragg order of semiconductor wall and three pairs were chosen. A deeply etched nitide/air DBR with vertical sidewall was obtained by focused Ga ion beam milling. Negative effects of the FIB on the etched GaN-based mirrors were also noticed. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Fabrication of field emitter array using focused ion and electron beam induced reaction

A 30 keV dual beam system with focused ion and electron beams has been used to develop a fast fabrication process of field emitter arrays (FEAs). The gate opening was fabricated by reactive focused ion beam etching. Pt cathode tips were deposited through gate opening using electron beam induced chemical reaction. Pt tips fabricated in the over-etched Si FEA showed field emission. A prototype of a nanometer-sized FEA was fabricated using a dual beam technique with FIB etching and electron beam induced deposition.

Cross-Sectional Tem Sample Preparation Method Using Fib Etching for Thin-Film Transistor

AbstractA rapid and precise sample preparation method using focused ion beam (FIB) etching was developed for cross-sectional transmission electron microscopy (X-TEM) analysis of a thin-film transistor (TFT) fabricated on a glass substrate. Gallium (Ga) ions accelerated at 30 kV and at various incident beam angles were applied during FIB etching to create a uniform thin wall. We successfully prepared X-TEM specimens of long and fragile aluminum (Al) whiskers formed on thin Al films in TFT metallization, where a strong charge is built up during FIB etching. The effect of ion-beam-assisted tungsten deposition prior to FIB etching is discussed. A whisker having a length not exceeding approximately 10 #x00B5;m can be successfully etched to a thickness of 200 nm while keeping its original shape. The performance of this technique is demonstrated in applications to etching at other fragile locations related to TFTs.

Electron beam testing of VLSI circuits assisted by focused ion beam etching

Electron beam testing assisted by focused ion beam etching was examined. Before electron beam testing (EB testing), a small window was made in the passivation film by focused ion beam etching (FIB etching). EB testing was performed through this window. This method was useful because charge buildup on the passivation film is avoided during EB testing. The threshold voltage shift caused by FIB etching was permitted until the residual film thickness on the gate electrode became 0.5μm. This technique was applied to measure the internal voltage waveform of the 256K bit dynamic RAM and confirmed that it was effective for functional testing and failure analysis of VLSI circuits.