We present a novel process for the fabrication of silicon tip emitters with self-aligned planar tungsten gate electrodes formed by low-temperature selective chemical vapor deposition. Emitters with tip radii of less than 20 nm and gate apertures with diameters of 0.5 mu m have been fabricated using this process. The planar nature of the process allows the integration of multiple additional planar tungsten electrodes to produce an entire micromachined electron gun on a single silicon substrate. The gate electrode is self-aligned. Misalignment of the lens electrodes, typically less than 0.25 mu m, can be corrected using integrated microelectromechanical actuators or multipole electrodes. Fabrication of multiple levels of complex suspended tungsten microstructures is demonstrated using a multiple level planar tungsten process. Test structures consisting of three levels of suspended tungsten honeycomb microstructures (1.5 mu m tungsten beam width, 5 mu m aperture diameter) and suspended microstages with integrated actuators are shown.