SEM observation of a specimen cross section can provide important information for research and development as well as failure analysis. In most cases, surface observation alone cannot provide information concerning the cross sectional structure of granular materials, layered materials, fibrous materials, and powders. Preparing highly-polished cross sections of these materials is both a science and an art.Typically, a cross section is prepared using mechanical means like conventional mechanical polishing methods or a microtome. The sample is first embedded in a holder or device, and then polished to achieve a flat cross section. In some cases, a staining procedure is used to highlight a specific component of the sample. Such methods can be lengthy procedures that require a great deal of skill, and can introduce artifacts into soft materials, deform the material around voids, or compress layers of soft and hard materials in composite samples. Mechanical polishing can miss fine details such as the presence of hairline cracks, and present a challenge to water-soluble phases.In other cases, a Focused Ion Beam (FIB) System is used when precise positioning of the cross section is required, such as in the case 2. Gold wirebond cross section prepared using the CP. The inset shows magnified view of grain structure and voids.of stacks of thin films or micro area specimen preparation. However, the size of the resulting cross section is limited, and the heavy gallium ions in the beam can damage the sample surface.A new precision argon ion beam cross section polisher simplifies the preparation of samples and makes it possible to prepare truly representative cross sections of samples free of artifacts and distortion. Use of the broad argon ion beam eliminates the problems associated with conventional polishing and allows for larger specimens to be prepared with precision. (1,2) The JEOL Cross Section Polisher (CP) consists of a specimen chamber with a turbo pump vacuum system, an optical microscope for specimen positioning, and controls for the vacuum system and stationary ion beam (Fig. 1). The specimen stage in the chamber features a holder and masking plate.To produce a cross section using the CP, the specimen is placed in the holder, and the region of the sample to be cross sectioned is selected under the optical microscope. The masking plate is placed across the selected region. After evacuating the specimen chamber, • miOROJCOPY TODflY May 2006COMPO 5.0kV X7.0003. Toner particles cross section prepared using the CP.

Hexamethyldisilane (HMDS, Si 2 (CH 3 ) 6 ) and tetraethylsilane (TES, Si(C 2 H 5 ) 4 ) were used as safe organosilane sources for the chemical vapor deposition of SiC films on Si(111) substrates. The surface morphology and crystalline quality of SiC films were investigated. On increasing temperature in H 2 ambient after carbonization, voids appeared at the interface of SiC/Si causing the formation of hillocks on the grown SiC films. The formation of voids was prevented by supplying C 3 H 8 and HMDS or TES during the heating process to the growth temperature, leading to the growth of SiC films with a good surface morphology. In the case of TES, the excess carbon incorporated in the film due to the high C/Si ratio was removed by reducing TES flow rate. It was found that the control of the flow rate of organosilane sources during heating plays a vital role in the formation of a high-quality SiC film with a smooth surface.

We present our theoretical investigations into the formalism of the transient effects during photorefractive two-wave mixing. An analytical model has been developed based on Kukhtarev's band-transport equations and on the linearization approximation. The physical phenomena involved during transients have been predicted for both drift and diffusion mechanisms. Good agreement is found when our model is compared with previous works, especially with the experimental measurements performed with BSO crystals by Heaton and Solymar. †

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