Manufacture of Metal Microelectrodes with the Scanning Electron Microscope

This communication describes a new method of manufacturing tungsten microelectrodes with finer tip size and more reproducible exposed recording area than has been previously achieved. The tips are dc electroetched to diameters below 500 A and completely covered with polymethyl methacrylate. An electron beam from a scanning electron microscope is then used to expose a precise area on the tip for later removal by chemical methods. Recording results with these electrodes suggest very good isolation properties.