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Fabrication and Characterization of Singly-Addressable Arrays of Polysilicon Field-Emission Cathodes. N.N. Chubun, A.G. Chakhovskoi, C.E. Hunt and M.Hajra Electrical and Computer Engineering Department, University of California, Davis, CA. 95616, U.S.A. ABSTRACT Polysilicon is a promising candidate material for field-emission microelectronics devices. It can be competitive for large-size, cost-sensitive applications such as flat-panel displays and micro electro-mechanical systems. Singly-addressable arrays of field-emission cells were fabricated in a matrix configuration using a subtractive process on Polysilicon-On-Insulator substrates. Matrix rows were fabricated as insulated polycrystalline silicon strips with sharp emission tips; and matrix columns were deposited as gold thin film electrodes with round gate openings. Ion implantation has been used to provide the required conductivity of the poly-Si layer. To reduce radius of curvature of the polysilicon tips, a sharpening oxidation process was used. The final device had polysilicon emission tips with end radii smaller than 15 nm, surrounded by gate apertures of 0.4 µm in diameter. Field emission properties of the cathodes were measured at a pressure of about 10-8 Torr, to emulate vacuum conditions available in sealed vacuum microelectronics devices. It was found that an emission current of 1 nA appears at a gate voltage of 25 V and can be increased up to 1µA at 70 V. Over this range of current, no “semiconductor” deviation from the Fowler-Nordheim equation was observed. I-V characteristics measured in cells of a 10x10 matrix, with a cell spacing of 50 µm demonstrated good uniformity and reproducibility. INTRODUCTION Low-voltage field-emission cathodes are a promising type of electron source for vacuum microelectronics devices. During the last ten years, a broad collection of new emissive materials such as diamond and diamond-like carbon, compound semiconductors, noble metals, etc., have been used for field-emission cathode fabrication. Single crystal silicon, because of its advantages in VLSI technology still remains one of the most frequently used materials for many applications including flat-panel display, multi-beam lithography, microscopy, and data-storage devices [1,2]. However as the size of the single-crystal Si substrates increases, the factors related to manufacturing cost and technological complexity impose further limitation on fabrication of the cathodes for flat-panel displays and micro electro-mechanical systems. Polycrystalline silicon may be considered as a good alternative to single crystalline silicon because it can be costeffectively deposited over larger size dielectric substrates and still be compatible with traditional semiconductor manufacturing methods. Recently, it was found by E. Boswell and colleagues in diode emission tests, that the polycrystalline silicon field emitters fabricated using wet etching method, exhibit an emission behavior similar to single crystal silicon emitters [3]. It was observed that the oxidation sharpening had l