• Applied Microscopy
• /
• v.41 no.3
• /
• pp.215-222
• /
• 2011

We discuss the experimental procedure for extracting reliable phase information from a defocus series of transmission electron microscopy (TEM) dark-field images using the transport of intensity equation (TIE). Taking InGaN/GaN multi-quantum well light-emitting diode as a model system, various factors affecting the final result of reconstructed phase such as TEM sample preparation, TEM imaging condition, image alignment, the correction of defocus values and the use of high frequency pass filter are evaluated. The obtained phase of wave function was converted to the geometric phase of the corresponding lattice planes, which was then used for the two-dimensional mapping of lattice strain following the dark-field inline holography (DIH) routine. The strain map obtained by DIH after optimized image processing is compared with that obtained by the geometric phase analysis of high resolution TEM (HRTEM) image, manifesting that DIH yields more accurate and reliable strain information than HRTEM-based GPA.

• Journal of the Microelectronics and Packaging Society
• /
• v.21 no.4
• /
• pp.63-68
• /
• 2014

For a nanoscale Cu/low-k wafer, inter-layer dielectric (ILD) and metal layers peelings, cracks, chipping, and delamination are the most common dicing defects by traditional diamond blade saw process. Sidewall void in sawing street is one of the key factors to bring about cracks and chipping. The aim of this research is to evaluate laser grooving & mechanical sawing parameters to eliminate sidewall void and avoid top-side chipping as well as peeling. An ultra-fast pico-second (ps) laser is applied to groove/singulate the 28-nanometer node wafer with Cu/low-k dielectric. A series of comprehensive parametric study on the recipes of input laser power, repetition rate, grooving speed, defocus amount and street index has been conducted to improve the quality of dicing process. The effects of the laser kerf geometry, grooving edge quality and defects are evaluated by using scanning electron microscopy (SEM) and focused ion beam (FIB). Experimental results have shown that the laser grooving technique is capable to improve the quality and yield issues on Cu/low-k wafer dicing process.

• Applied Microscopy
• /
• v.38 no.4
• /
• pp.363-374
• /
• 2008

In this paper we have examined the usefulness of IWFR (the iterative wave-function reconstruction) analysis for through-focal series of high-resolution images for a relative thick crystal. In the work we employed JEOL ARM 1300S, and observed the high-resolution images for a Si crystal at the two orientations of [01-1] and [11-2] having 30 nm and 35 nm thickness respectively. As a result of applying IWFR method on the images we found out that even for a thick crystal by the method we can retrieve the exit-surface wave function. However because of the strong dynamical scattering effect, the image pattern of the function reflects only qualitatively the atomic column structure of the crystal examined. Nevertheless it is no doubt that the pattern would give important clue for the crystal structure.