Areal array of tubular electron sources

Apparatus for producing a plurality of discrete electron beams, comprising in combination:

• (a) an electrically conductive back plate,
• (b) an electrically conductive face plate having a first array of holes therein,
• (c) a plurality of parallel tubes extending between said back plate and said face plate, a first end of each of said tubes closed and joined to said back plate and a second end of each of said tubes open and aligned with one of said holes in said face plate, said tubes contacting said face plate,
• (d) means for causing heating current to flow along the length of said tubes for heating said tubes to produce thermionic electron emission therefrom,
• (e) an extraction lens comprising a plate having a second array of holes therein registering with said first array, said extraction lens parallel to and spaced apart from said face plate opposite said back plate, and
• (f) means for electrostatically biasing said extraction lens relative to said tubes to produce a collimated beam of electrons from within each of said tubes.

Apparatus for producing a plurality of directed electron beams for simultaneous impact on a target comprising in combination:

• (a) a parallel array of tantalum tubes,
• (b) a first conductive plate joined to an end of each of said electrodes and closing said one end thereof,
• (c) a second conductive plate joined to the open end of each of said electrodes, said second plate having an array of holes therein aligned with and open to each of said electrodes,
• (d) an electrical current source connected between said first and said second plates for causing heating current to flow along the length of each of said tubes resistively to heat said tubes to produce thermionic emission of electrons therefrom,
• (e) means to establish a magnetic field parallel to said tubes to control the direction of travel of said electrons from said tubes,
• (f) a lens unit comprising a conductive plate spaced from and parallel with said second plate, said lens unit having an array of holes with one of said holes aligned with the axis of each of said tubes,
• (g) a direct current source connected to electrostatically bias said lens unit positive relative to said second plate to attract electrons from said electrodes and direct said electrons through said holes in said lens unit,
• (h) a direct current source electrostatically biasing said target positive relative to said tubes to accelerate said electrons toward said target, and
• (i) a third plate having an array of deflection holes therein aligned with the axes of said tubes, each of said beams passing through one of said deflection holes, each of said deflection holes having electrostatic deflection electrodes therein for directing the electron beam passing therethrough to a selected point on said target.

In electron beam lithography where a semiconductor target wafer is exposed by a directed electron beam in producing a monolithic semiconductor device, apparatus for simultaneously producing a plurality of directed electron beams comprising in combination:

• (a) a plurality of tubular, electron-emissive units aligned in a parallel array, each of said units closed at one end and open at the opposite end,
• (b) means for heating said units to produce thermionic emission of electrons,
• (c) means for extracting said electrons from the interior of said units through said open end thereof to generate a collimated electron beam from each of said units,
• (d) means for accelerating each of said electron beams toward said wafer,
• (e) means for focusing each of said electron beams, and
• (f) means for deflecting each of said electron beams to expose selected points on said wafer.

In a display system where an electron beam impacts a phosphor sceen to produce luminance, apparatus for simultaneously producing a plurality of directed electron beams to create an image on the screen comprising in combination:

• (a) a plurality of tubular, electron-emissive units aligned in a parallel array, each of said units closed at one end and open at the opposite end,
• (b) means for heating said units to produce thermionic emission of electrons,
• (c) means for extracting said electrons from the interior of said units through said open end thereof to generate a collimated electron beam from each of said units,
• (d) means for accelerating each of said electron beams toward said screen,
• (e) means for focusing each of said electron beams, and
• (f) deflection means for aiming each of said electron beams to desired points on the surface of said screen to produce said image.