Electron beam imaging

Figure 3 high resolution TEM images with Fourier transforms showing the real-time degradation of the BEA framework under a 200 kV accelerated electron beam images at a) time = 0s and after b) 10s, c) 20s and d) 40s. 

Figure 44. Schematic of electron beam image projection systems (a) image formed by electrons emitted from a photocathode, and (b) image formed by an absorbing mask pattern on an electron transparent substrate.

Figure 8. Electron micrographs of a trilevel aluminum lift off process employing a typical polysilane as the 02-RIE barrier. Key left, electron-beam imaged and right, optically imaged Mann step and repeat.

Figure 3 Photomicrographs of cathodic products of the system NaCl-KCl-C02, obtained at different electrolysis conditions (a) - gray coating (EK = - 0,6 V, PC02= 10 105 Pa T= 750 C) (b) - black coating and its electron -beam image (c) (EK = -1 V, Pco2= 5 105 Pa T= 850 C) (d), (i), (f) - fragments of black powders produced at PC02= 10 105 Pa T= 750 C and ik (mA/sm2) = 13.5 28 56 corresponding.

Figure 12. Electron beam imaging of poly(di-n-pentylsilane) (0.14 ym) coated over 2.0 xm of a hard-baked AZ-type photoresist exposed at 20 iClcm and wet developed. Pattern transfer was by O2-RIE.

In the PCM systems just described, both top and bottom resists are positive working. Residual exposure of a bottom positive resist during UV or electron beam imaging of a positive top resist is acceptable. However, when a negative resist is used as the top layer, the residual exposure may reduce the contrast of a bottom positive resist. The several PCM systems involving the use of a negative resist as a top layer listed in Table 3.8 (imaging layers 3-6) indicate that if there is a sufiScient sensitivity difference between the top and the bottom resists, the residual exposure can be tolerated. 

The use of organometallic polymers in the bilevel RIE-PCM scheme was first reported by Shaw et al. (185). They used polysiloxane (structure 3.16) as a negative-working electron beam imaging layer. The etch rate ratio... 

I. Mori, K. Sugihara, C. Itoh, M. Tabata, and T. Schinozaki, An electron beam image projection system with automatic wafer handling, Microelectron. Eng. 3, 69 (1985) T.W. O Keefe, J. Vine, and R.M. Handy, An electron imaging system for the fabrication of integrated circuits, Solid... 

The use of focused electron beams as a source for forming high resolution images is the most mature of the advanced technologies. Electron beams are used to prepare numerous custom devices and are used extensively in the preparation of optical masks. The following discussion will be limited to selected examples of the types of polymers used for electron beam imaging and the chemistries that govern their behavior. An extensive review attests to the enormous interest and effort put forth in this area. 

The history of EM (for an overview see table Bl.17,1) can be interpreted as the development of two concepts the electron beam either illuminates a large area of tire sample ( flood-beam illumination , as in the typical transmission electron microscope (TEM) imaging using a spread-out beam) or just one point, i.e. focused to the smallest spot possible, which is then scaimed across the sample (scaiming transmission electron microscopy (STEM) or scaiming electron microscopy (SEM)). In both situations the electron beam is considered as a matter wave interacting with the sample and microscopy simply studies the interaction of the scattered electrons. 

EM instmments can be distinguished by the way the infonnation, i.e. the interacting electrons, is detected. Figure Bl.17.2 shows the typical situations for TEM, STEM, and SEM. For TEM the transmitted electron beam of the brightfield illumination is imaged simply as in an light microscope, using the objective and... 

Except for the phase-contrast detector in STEM [9], STEM and SEM detectors do not track the position of the recorded electron. The spatial information of an image is fonned instead by assigning the measured electron current to the known position of the scaimed incident electron beam. This infomiation is then mapped into a 2D pixel array, which is depicted either on a TV screen or digitalized in a computer. 

Keller D and Chou C C 1992 Imaging steep, high structures by scanning force microscopy with electron beam deposited tips Surf. Sol. 268 333... 

In many ways the nanocrystal characterization problem is an ideal one for transmission electron microscopy (TEM). Here, an electron beam is used to image a thin sample in transmission mode [119]. The resolution is a sensitive fimction of the beam voltage and electron optics a low-resolution microscope operating at 100 kV might... 

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