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Thin Film Electron Emission Source

IP.com Disclosure Number: IPCOM000074277D
Original Publication Date: 1971-Apr-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 42K

Publishing Venue

IBM

Related People

Cuomo, JJ: AUTHOR

Abstract

Since the work function of lanthanium hexaboride is low (2.56 ev.) it is an extremely important electron emission material, its use including application as both a hot emitter and a cold emitter.

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Thin Film Electron Emission Source

Since the work function of lanthanium hexaboride is low (2.56 ev.) it is an extremely important electron emission material, its use including application as both a hot emitter and a cold emitter.

Films of lanthanium hexaboride have been prepared by RF sputtering on sapphire, polycrystalline Al(2)O(3), MgO and mica. The films on sapphire have a preferred (100) orientation normal to the (0001) sapphire surface.

A hot electron emitter, as shown in Fig. A, was prepared by RF sputtering lanthanium hexaboride through a mask, so as to form a thin filament 1 on substrate 3. When current is passed through the filament leads, from potential source 5, the filament is easily heated to 1200 degrees C, with only 7 watts of power dissipated.

Fig. B shows an alternative hot electron emitter arrangement which may be prepared by RF sputtering. As shown a layer of lanthanium hexaboride 7 is first deposited upon substrate 9. Thereafter, a layer of insulation 11 is deposited upon the lanthanium hexaboride and a layer of metal 13 is deposited upon the layer of insulation. An orifice 15 is cut into metal layer 13 and insulation layer 11, whereby upon application of the potential source 17 across the metal layer and layer of lanthanium hexaboride electrons are emitted through the orifice.

Fig. C shows a cold electron emitter arrangement. As shown, a layer of lanthanium hexaboride 19 is deposited upon substrate 21. Thereafter a thin layer of insulation...