| Vacuum microelectronic devices involve field emission of electrons in a vacuum with solid-state integrated circuits fabrication technology. For the past three years, the outstanding features of these new devices have attracted scientist's attention world wide.;The first step of our work is the design of diode and triode arrays. Both arrays are designed by using a "Building Block" method to simplify the fabrication procedures and reduce the number of masks. The "Building Block" method was developed in our Integrated Microelectronics Laboratory at the University of Kentucky. The advantage of this method is that it yields a very simple assembly process; the disadvantage of this method is that it requires high alignment precision for placing the grid plate for the triode array.;The second step of this work is the fabrication of the vacuum microelectronic diode. We use an anisotropic etching technique in silicon processing and micromachining to construct the building blocks. All fabrication procedures are based on advanced integrated circuit processing techniques including silicon wafer oxidation, photoresist coating, photoresist exposure and developing, oxide window etching and, finally, a silicon micromachining technique to construct the miniature structure on the silicon wafer.;The last step of our experiment is the device modeling of our physical structure. By solving Laplace's Equation with simplified boundary conditions we obtain an expression for the electric field intensity at the surface of the silicon emitter tip. We use the Fowler-Nordheim Equation and the resulting electric field intensity calculated above to model the experimental I-V curve of our diode. We were unable to fabricate the proposed triode structure, but we created a triode model for calculating the triode's I-V characteristics.;Combining the results of this calculation with the dimensions of a Russian triode reported by V. I. Makhov, we found our calculated triode I-V curves to compare favorably with the experimental plots from the Russian's work. |
