In 1965, Gordon Moore forecast that the microprocessor industry would continually scale to smaller feature sizes and the number of transistors would double every 18 months. Scaling below the 100nm node, combined with the implementation of copper and low dielectric constant insulators to increase the processor speed, has produced the situation in which SEM inspection no longer offers suitable resolution to image key artifacts and structures. The transmission electron microscope (TEM), once considered more of a development tool, is now in the forefront for process control and failure analysis, especially for measurements such as the thickness of semiconductor device non-planar barrier and seed layers

Confocal Holography is a combination of two well known concepts: confocal microscopy and light (laser) holography. Confocal microscopy places an aperture at a conjugate focus to the specimen focus. This filters any rays that are not on the focus plane, allowing a 3-dimensional image of the specimen to be built up over a set of planes.

Holography is the measurement of both the amplitude and phase characteristics of light. Typically most methods only measure the amplitude of the image. The phenomenon of interference allows the determination of the phase shift for a coherent source as well. The phase information is directly related to the index of refraction of a material, which in turn is a function of the temperature and composition.

Historically, SEM developed as a high vacuum technique requiring sample chamber vacuum of 10-5 Torr or better. Energetic electrons scatter from any molecules they encounter, so their creation and transport from source to sample, through the focusing lenses of the electron column, requires high vacuum. This imposes a number of limitations on the kinds of samples that can be examined. Samples must tolerate the vacuum environment and the vacuum system must tolerate the sample. Generally, samples have to be solid, clean, dry, and not contain volatile components. Furthermore, since the vacuum insulates the sample from everything except the stub that supports it, non-conductive samples require a conductive pathway between the scanned region and ground to prevent the accumulation of charge deposited by the beam electrons.

Electron-beam lithography offers very high resolution patterns without the need for masks. Systems based on electron microscopes offer entry into electron-beam lithography at reasonable cost. Such systems are becoming popular in research environments due to their versatility and reasonable cost.

While these systems work well they do have problems writing on insulating substrates. The insulating substrate causes charge to build up from the incident electron-beam. As the charge builds up on the surface of the insulator, the incident beam is distorted and moved in x and y. The result is a lack of positioning accuracy on the patterns as well as pattern distortion.

Image acquisition in a TEM requires the conversion of the electron image into a photon image and the acquisition of this photon image with an imaging device. There are two principal techniques to do so: a fiber-coupled camera and a lens-coupled camera. Both have advantages and disadvantages. Please be aware that we (Soft Imaging System Corp) produce both types of cameras. There are also two principle camera positions on a TEM, and the choice of position must be taken into account for any decision. The positions are: side-mount (camera mounted on 35mm port above the viewing chamber), and bottom-mount (also known as on-axis mount, camera mounted below the viewing chamber).

The stereo microscope is the most commonly used microscope. This applies to both the materials science and biological science fields. My past career as a materials engineer depended critically upon the three dimensional imaging of the stereo microscope for studying metal parts and fracture surfaces. Unfortunately our clients had no readily available way to view stereo pairs, so stereo pair recording was not done. Likewise, our electron microscopes were not equipped with costly eucentric stages, which make stereo pair recording easily done.

Automated analysis of Electron Backscatter Diffraction (EBSD) patterns for orientation imaging and phase identification in materials and earth sciences has become a widely accepted microstructural analysis tool. To briefly review, EBSD is a scanning electron microscope (SEM) based technique where the sample is tilted approximately 70 degrees and the electron beam is positioned in an analytical spot-mode within a selected grain. An EBSD pattern is formed due to the diffraction of the electron beam by select crystallographic planes within the material. The EBSD pattern is representative of both the phase and crystallographic orientation of the selected area. The pattern is imaged by a phosphor screen and recorded with a digital CCD camera and then analyzed.

Electron microscopy (EM) is an indispensable tool for the study of ultrastructures of biological specimens. Every electron microscopist would like to process biological specimens for either scanning electron microscopy (SEM) or transmission electron microscopy (TEM) in a way that the specimens viewed under the electron microscope resemble those seen in vivo or in vitro under the light microscope. This is, however, often easier said than done because biological tissue processing for EM requires careful attention of the investigator with regard to the numerous processing steps involved in specimen preparation, such as fixation, dehydration, infiltration, embedding, and sectioning.

When a sixty thousand dollar microscope is used as a paint brush, neither science nor art are in trouble - but rather benefactors, witness to the fact that there can be "science in art" and "art in science."

Arguably, except for a very few kids, our high schools are churning out hamburger helper generations, the product of a defective educational philosophy that believes that self esteem is more important than inspiring a tough academic regimen that leads to the pursuit of a science-focused secondary and post secondary education. Horses drink water because they want to, not because they were led to it. Kids pursue science and the achievement of excellence not because it is available, but rather because somewhere along their early education experience someone inspired their interest and curiosity.

Presently, there is an increasing demand for multi-view TEM observation of semiconductor device failure locations where the feature size of interest is smaller than the specimen thickness, and where the thin section has other features that may have high Z materials that obscure the site of interest in the TEM. Therefore, different viewing angles are necessary — such as a cross-section view of a defect-containing planar thin specimen. A major obstacle for the preparation of three dimensional specimens of this nature is specimen preparation. Great care must be taken when preparing a thin specimen from an already thin existing TEM specimen.

Salary Surveys always create considerable interest. Although a less formal study was conducted several years ago via the Microscopy Society listserver, the authors are not aware of a complete study since the one conducted by the MSA nearly 20 years ago. The current study followed a format frequently used by Microscopy/Microscopy Education (MME), typically delivered at microscopy-related scientific meetings to gather trends on new and existing instrumentation. It was mailed the middle of 2004 to nearly 15,000 US readers of Microscopy Today. Returns were collected and processed by an independent contractor.

In an optical tweezers system, the output signal of a photodiode quadrant detector and the temperature in a sample cell are two key factors for the quantitative measurements of mechanical properties of living biological objects such as cells, organelles and macro-molecules. In order to enhance the output of a quadrant detector and effectively control the temperature in a sample cell, the dependence of the temperature in the sample cell and the output of the quadrant detector for different illumination conditions are studied. The results show that appropriate illumination conditions can ensure both nearly constant temperatures in the cell and the desired output signal, which provides for the possibility of highprecision and damage-free analysis of living biological objects.

ASTM International publishes many standards specifically about microscopes and using microscopy. The value of these standards falls into three distinct categories. First, they can be a quick tutorial on how to perform some operation. E 1508, "Standard Guide to Quantitative Analysis by EDS" is only eight pages long and falls into this category. Second, they can be used to standardize a test and reporting method. The methods described in E 1382, "Standard Test Methods for Determining Grain Size by Semiautomatic and Automatic Image Analysis" are examples of procedures that have been agreed upon for many years.

The increased emphasis on nano-structured materials is placing an ever increasing demand on sample preparation techniques to unveil such fine structure. Nano-structured fibers are even more difficult because of the ease with which these materials can smear even when prepared under liquid nitrogen (LN2) as shown (Figure 1). This is especially true for the islandin- the-sea structures where it is rather hard to reveal the island structures due to smearing. In the search for a possible solution, a sample preparation technique that has shown great results in other composite structures of different polymer blends was applied to these structures.

At the Microscopy and Microanalysis conference in Honolulu this last August a small meeting was convened to share information and knowledge about implementing LIMS (Laboratory Information Management Systems). The meeting took place at the end of the session on Core Facility Management, through the efforts of Debby Sherman, who is coordinator of the Core Facility Managers Focused Interest Group (http://microscopy.org/MSAUnits/Committees/ Facilities.html). In addition to the meeting, I spoke with several vendors (focusing on those vendors we use here at PathBioResource), as well as others who have made some progress in developing and/or installing LIMS.

The microwave oven is a valuable tool for light and electron microscopy microtechnique labs. Tissue processing times, traditionally taking up to two weeks, have been reduced to a few hours as a result of the implementation of microwave technology (Kok et al., 1988, Gibberson and Demaree, 2001). In addition, the quality of the tissue preparations has improved dramatically. Microwave ovens have also evolved since their first use in the laboratory. Early experiments were conducted using relatively crude commercial microwave ovens. Now, labs use microwave ovens with temperature probes, strict control over the magnetron (which generates the microwaves), variable power supplies, chamber cooling, and high microwave field uniformity.