Fabricating a Bistable Niobium Oxide Switch
Original Publication Date: 1972-Sep-01
Included in the Prior Art Database: 2005-Feb-25
Publishing Venue
IBM
Related People
Berkenblit, M: AUTHOR [+3]
Abstract
A method is provided for simplifying the fabrication of a bistable niobium oxide switch. The device comprises a neutral substrate on which is deposited a layer of niobium, over which is lain a niobium oxide film, and over that is placed an electrode of bismuth. A positive voltage, above a predetermined threshold, will switch the niobium oxide to its low-impedance state and a threshold negative voltage will switch the niobium oxide to its high-impedance state.
Fabricating a Bistable Niobium Oxide Switch
A method is provided for simplifying the fabrication of a bistable niobium oxide switch. The device comprises a neutral substrate on which is deposited a layer of niobium, over which is lain a niobium oxide film, and over that is placed an electrode of bismuth. A positive voltage, above a predetermined threshold, will switch the niobium oxide to its low-impedance state and a threshold negative voltage will switch the niobium oxide to its high-impedance state.
One method (See Fig. 1A) starts with a substrate 2 of glass, silicon, or the like, over which is deposited a thin layer of niobium 4. The latter is anodized to produce a layer 6 of Nb(2)O(5) which is between 300-1500 Angstroms thick. Photoresist layer 8 is deposited through a suitable mask on the Nb(2)O(5) layer and all the niobium, save that protected by the photoresist, is anodized (see dashed portion of Fig. 1B). The photoresist is then removed so that in its place can be inserted the bismuth that serves as one electrode of the switch, with niobium 4 serving as the other electrode.
Figs. 2A, 2B and 2C delineate the steps of an alternate way of making the desired Nb(2)O(5) switch. First a niobium layer 4 is deposited on substrate 2 prior to employing a photoresist 8. The Nb is anodized to completion save for the area under the photoresist. After anodization, the photoresist is removed and a layer 6 of Nb(2)O(5) is deposited by sputtering, using an electron gun, e...