Silicon-based integrated emitters

Miniaturized LC/MS formats based on micromachined chip-based electrospray emitters and ionization sources on silicon (Schultz et al., 2000 Licklider et al., 2000 Ramsey and Ramsey 1997 Xue et al., 1997) and plastic (Vrouwe et al., 2000 Yuan and Shiea, 2001, Tang et al., 2001) microchips is a proactive approach for scale-down platforms. Various micromachining processes are used to fabricate these devices. These microanalytical technologies would create integrated sample preparation and LC/MS applications. The potential benefits of such a system include reduced consumption of sample/reagents, low cost, and disposability. 

Hybrid integration of light emitters and detectors with SOI-based micro-opto-electro-mechanical (MOEMS) systems, Proc. SPIE 4293, Silicon-Based and Hybrid Optoelectronics III, D.J. Robbins, J.A. Trezza, G.E. Jabbour, Eds., pp. 32-45 (2001). 

To achieve the lowest possible delay a bipolar switching transistor developed by IBM minimizes parasitic resistances and capacitances. It consists of self-aligned emitter and base contacts, a thin intrinsic base with an optimized collector doping profile, and deep-trench isolation (36). Devices must be isolated from each other to prevent unwanted interactions in integrated circuits. While p—n junctions can be used for isolation, IBM s approach etches deep trenches in the silicon wafer which are filled with Si02 to provide electrical insulation. 

Fig. 3.3. Acoustic micrographs taken in superfluid helium at 0.2 K. (a) Bipolar transistor on a silicon integrated circuit. The aluminium lines making connections to the base and the emitter are 2 fan wide and 0.5 fan thick. Three images were taken at different heights, and superimposed with colour coding. The lens had a numerical aperture N.A. = 0.625 and a depth of focus less than 150 nm, / = 4.2 GHz. (b) Myxobac-terium, with different planes similarly colour-coded and superimposed, / = 8 GHz...

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