Beam failure analysis

Laser ionization mass spectrometry or laser microprobing (LIMS) is a microanalyt-ical technique used to rapidly characterize the elemental and, sometimes, molecular composition of materials. It is based on the ability of short high-power laser pulses (-10 ns) to produce ions from solids. The ions formed in these brief pulses are analyzed using a time-of-flight mass spectrometer. The quasi-simultaneous collection of all ion masses allows the survey analysis of unknown materials. The main applications of LIMS are in failure analysis, where chemical differences between a contaminated sample and a control need to be rapidly assessed. The ability to focus the laser beam to a diameter of approximately 1 mm permits the application of this technique to the characterization of small features, for example, in integrated circuits. The LIMS detection limits for many elements are close to 10 at/cm, which makes this technique considerably more sensitive than other survey microan-alytical techniques, such as Auger Electron Spectroscopy (AES) or Electron Probe Microanalysis (EPMA). Additionally, LIMS can be used to analyze insulating sam-... 

MelngaiUs, AppUcations of ion microbeams in lithography and direct processing, Handbook of VLSI Microlithography, 2nd ed., J.N. Helbert, Ed., William Andrew Inc., pp. 790 855 (2001). Other applications of focused ion beam in integrated circuit industry include device repair, failure analysis, and direct implantation of ions into substrates. 

The principle of Auger electron spectroscopy (AES) is illustrated schematically in Figure 7. Here, a primary beam of electrons incident on a solid results in the emission of secondary (or Auger) electrons from the top 5 nm of the sample. The energy of the Auger electrons is characteristic of elements contained in the outer surface. Both elemental identification and atomic concentrations can be obtained from AES. The AES technique is not widely used in post-failure analysis of adhesively bonded... 

In failure analysis the possibility to record all elements is advantageous, not least in combination with 3D imaging (i.e., a TOF-SIMS instrument with dual-beam capability is the instrument of choice). An example is the investigation of black spots in OLEDs where a fluorine-based polymer was sandwiched between a metallic cathode consisting of Ba and A1 and a poly(3,4-ethylenedioxythiophene)/ITO anode. From the recorded raw data, depth profiles can be reconstructed as well as two-dimensional (2D) images in any depth or a 3D representation of all interesting signals. It was found that aluminum was oxidized at the Al/polymer interface [220]. 

Each of these steps depends on the process before. The software suite starts with the material selection, in which also an individual material can be dehned. Fiber orientations and the number of plies can be selected in a following step. All material parameters must be chosen before the analysis can start. Six structural analysis modules can be differentiated with the CDS software suite. These solid mechanic modules are thick-walled cylinder, thin plate, thin plate impact-fastener modeling, thick plate, discontinuous tile modeling and compliant beam interlayer analysis. The CDS software suite allows changing the parameters of the manufacturing process or the laminate structure in real time. Four result sections for those parameter changes are provided by the software the effective properties, thermal-processing response, stress-strain results and the failure response. The CDS software suite is a complete analysis tool kit which is easy to use for the client. The software also allows export into an external simulation tool. 

It is common for liquid nitrogen frozen protein crystals to acquire a patina of ice on the surface of the cryoprotectant. Diffraction of X-rays from even small ice crystals can mask reflections from the protein crystal. In addition, the presence of excessive amounts of ice can obscure the true position of the nylon loop, thereby resulting in the failure to place the crystal in the X-ray beam. It is, therefore, essential to remove ice crystals prior to diffraction analysis. 

The fringes are created by the rotation of the sample along an axis which is parallel to the fundamental beam polarization. Since many of the samples have strong absorptions at 3co, care was taken to include accurate measurements of both the polymer refractive index and absorption coefficient at 3m in the analysis. Failure to... 

Ion beams provide useful information either as a diagnostic tool or as a precision etching method in. adhesive bonding research. The combination of SIMS with complementary methods such as ISS or AF.S provides a powerful tool for elemental end limited structural characterization of metals, alloys and adhesives. The results shown here indicate that surface chemistry (and interface chemistry) can be decidedly different from bulk chemistry. Often it is this chemistry which governs the quality and durability of an adhesive bond. These same surface techniques also allow an analysis of the locus of failure of bonded materials which fail in service or test. 

Ion beams provide useful information either as a diagnostic tool or as a precision etching method in adhesion research. The combination ISS/SIMS method used along with other techniques such as SEM provides a powerful tool for elemental analysis of surface composition. These results, as well as earlier work in this laboratory, indicate that the surface composition can be significantly different from the bulk due to contamination, selective chemical etching and segregation. These same techniques also provide an analysis of the mode of failure in adhesive joints. Many failures classified as "adhesive" on the basis of visual inspection are frequently mixed mode failures or failures at a new interface containing elements of both adhesives and adherend. 

Corrective action procedures were documented for this process and included items on verifying process conditions, such as weld beam energy and fiber gap position, estabhshing failure mode analysis procedures, determining disposition of work in process, and confirming procedures for restarting the process. 

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