FEA with suspended focusing electrode
Publication Date: 2001-Sep-18
The IP.com Prior Art Database
The basic idea is to improve the focus of the electron beams emitted from tips in a gated FEA by mounting a suspended "focusing" electrode on the FEA chip using MCNC's flip chip technology. The gated FEA chip could be fabricated using standard FEA processing schemes with one additional feature. Solder bump pads would be deposited around the perimeter of the array on the chip (see Fig. 2a). A second die (ceramic or some other rigid material) would be patterned, etched (formation of through holes), patterned again, metallized (on both sides), and solder bumped to "mate" with the FEA chip (see Fig. 2a). The solder bumps would be electrically isolated from the field metal of the focusing electrode. Then, the focusing electrode would be "flipped" on to the FEA chip using techniques developed previously at MCNC. Figure 2b illustrates a side view of the resulting structure. The distance of the focusing electrode from the gate electrode is dependent upon the size of the solder bumps used to bond the two chips together. In theory, a substantial gap between the focusing and gate electrodes should lead to improved focusing of the field emitted electron beams.