Parameter dispersion characterization for arrays of HfC-coated emitters on poly-Si substrate

Abstract

Articles you may be interested inMetal coated silicon spike cold-electron emitters show improvement of performance with operation Appl. Phys. Lett. 96, 033501 (2010); 10.1063/1.3291672HfC field emitter array controlled by built-in poly-Si thin film transistor HfC-coated poly-Si field-emission arrays ͑FEAs͒ were produced, and the emission statistics were characterized using a model parameter extraction. The poly-Si, chosen as a substrate, allows the integration of FEAs with control circuits and the scaling up of the fabrication process to larger dimensions, as required by field-emission display applications. The Ar ion sputtering process was used for emitter sharpening, and structures with HfC coatings with different thicknesses were realized. The array field-emission model is built up using equations that describe the electron emission from individual emitters. A general analytical relationship for computing the electric field on the emitter apex was derived. Nonuniform distribution functions within the array for the tip radius and work function are considered. A modified Fowler-Nordheim diagram was used, the emission data current-voltage I-V being represented as ln͑I / V 3 ͒ as a function of 1 / V. A fast and accurate model parameter extraction is performed using a nonlinear extraction algorithm, considered over the entire voltage range for the measurements. The Ar ion sputtering process produces uniform emitters with smooth surfaces, increasing slightly the tip radius. The HfC coating lowers the work function and makes the emitter tips more blunt. An optimum thickness of the HfC layer is shown to exist. The number of active emitters responsible for most of the emission current is derived from the model and compared with direct counts.

Analysis of slope-intercept plots for arrays of electron field emitters

“…26,27 The distribution of most parameters is most likely a log-normal distribution (negative values for height and radius from a normal Gaussian distribution would not make sense). A log-normal distribution for the radius has also been observed by Ding et al, 28,29 as well as by Park et al for the field enhancement factor. 30…”