Electron beam assisted platinum film deposition has been found to be an effective method to protect the sample surface for both FIB and TEM analysis. In this paper, the phenomena of electron beam assisted deposition of platinum will be reviewed The results suggest that a 45 nm thick residual Pt film can effectively protects (100) silicon from damage induced by ion beam assisted Pt deposition. A carbon based organic layer under the electron beam assisted Pt has been observed. The mechanism and results on exposed oxide thickness measurements will be discussed. It is suggested that a carbon glue cap be used as a protective layer or polysilicon be deposited in line before submitting the wafer for TEM sample preparation and observation.

This paper studies the effects of an electron beam and an ion beam in sample preparation at the borderless bit-line contact (CB) between a transistor and a bit line in a deep trench capacitor DRAM [1] using the Transmission Electron Microscope (TEM) and the Electron Energy Loss Spectroscope (EELS). An abnormal region in the Si substrate was observed using cross-sectional TEM (XTEM) analysis at both the opened and un-opened CB contacts when normal sample preparation procedures were applied. CBED (Convergent Beam Electron Diffraction) in the TEM verifies this region is a structure of amorphous Si. The EELS spectrum shows the relative thickness (t/λ) of the TEM sample at this amorphous region is similar to that of the single crystal Si substrate. Experimental results demonstrated that this region was the result of radiation damage caused by either the ion-beam scan or the ion-beam Pt metal deposition required for sample preparation in the Focused Ion Beam (FIB) system. This radiation damage was not caused by inline wafer processing. However, the radiation damage zone for an un-opened contact is smaller than that for an opened contact. The size of the radiation damage zone increases relative to the time of the ion beam exposure. Using electron-beam scan and electron-beam Pt metal deposition can prevent this radiation damage from occurring.

Surface micromachined micromirror technologies are being employed for various commercial and government applications. One application of micromirror technologies in the commercial sector can be found in Digital Light Projection (DLP™) systems used for theater and home entertainment centers. DLP™ systems developed by Texas Instruments uses DMD™ technology (Digital Mirror Device), an array of micromirrors, to project light onto a screen [1]. This technology is also used by Infocus™ projection systems and widescreen tabletop televisions [2]. Here, the micromirrors act as individual pixels, reflecting light onto the screen with high ¡§digital¡¨ resolution. The most recent application of surface micromachined micromirror technology is optical switching [3], which uses micromirrors to switch optical signals from fiber to fiber for lightwave telecommunications [4]. Companies such as Lucent have fabricated entire optical micromirror switching systems based on their Microstar™ technology [5]. For government applications, surface micromachined micromirror arrays have been developed for potential use in a spectrometer system planned for NASA's Next Generation Space Telescope (NGST) [6]. Various processing technologies are used to fabricate surface micromachined micromirrors. The micromirror arrays developed by TI and Lucent [1,4] uses metal for their structural and reflective components. Micromirrors fabricated at Sandia National Laboratories use the SUMMiT™ (Sandia's Ultra-planar MEMS Multi-level Technology) process with metal deposited on the surface of mechanical polysilicon components to reflect light. Optical micromirror arrays designed and fabricated at Sandia for potential use in the NGST have undergone reliability testing and failure analysis. This paper will discuss the failure modes found in these micromirrors after reliability testing. Suggestions and corrective actions for improvements in device performance will also be discussed.