Methods of making infrared photoconductors with passivation control

Claim 1

A method of making an infrared detector from a semiconductor substrate doped slightly conductive, which method includes the following steps: (a) prepare the substrate and coat one side thereof with an ohmic contact metal; (b) deposit a layer of semiconductor photoconductor material on the opposite side of said substrate from said metal; (c) mask the photoconductor layer; (d) remove the unmasked portion of the photoconductor layer; (e) remove the mask; (f) deposit an overlayer of the same material as the substrate atop the bared substrate and the remaining photoconductive layer; (g) mask the overlayer for detector ohmic contacts; (h) remove the unmasked portions of the overlayer and a portion of the photoconductor layer to form cavities therein; (i) deposit ohmic contact material atop the mask and onto the bottoms of said cavities; (j) remove the mask and the contact material thereon; (k) coat the overlayer and the surfaces of the cavities with a Schottky barrier metal; (l) mask the metal; (m) remove the unmasked portions of the metal whereby read contacts remain atop the overlayer and connect to the ohmic contacts in said cavities; (n) remove the mask; and (o) apply bonding leads to the read contacts.

Claim 2

A method of making an infrared detector from a semiconductor substrate doped slightly conductive, which method includes the following steps: (a) prepare the substrate and coat one side thereof with an ohmic contact metal; (b) deposit a layer of semiconductor photoconductor material on the opposite side of said substrate from said metal; (c) mask the photoconductor layer; (d) remove the unmasked portion of the photoconductor layer; (e) remove the mask; (f) deposit an overlayer of the same material as the substrate atop the bared substrate and the remaining photoconductive layer; (g) mask the overlayer for detector ohmic contacts; (h) remove the unmasked portions of the overlayer and a portion of the photoconductor layer to form cavities therein; (i) deposit ohmic contact material atop the mask and onto the bottoms of said cavities; (j) remove the mask and the contact material thereon; (k) coat the overlayer and the surfaces of the cavities with a Schottky barrier metal; (l) mask the metal; (m) remove the unmasked portions of the metal whereby read contacts remain atop the overlayer and connect to the ohmic contacts in said cavities; (n) remove the mask; and (o) apply bonding leads to the read contacts.

Claim 3

A method of making an infrared detector from a semiconductor substrate doped slightly conductive, which method includes the following steps: (a) prepare the substrate and coat one side with an ohmic contact metal; (b) deposit a layer of semiconductor photoconductor material on the opposite side of said substrate from metal; (c) deposit atop said material an overlayer of the same material as the substrate; (d) mask the overlayer for detector ohmic contacts; (e) remove the unmasked portions of the overlayer and a portion of the photoconductor layer to form cavities therein; (f) deposit ohmic contact material atop the mask and onto the bottom of said cavities (g) remove the mask and the contact material thereon; (h) deposit a layer of Schottky barrier metal atop the overlayer and onto the walls and bottoms of said cavities; (i) mask for detector delineation; (j) remove the unmasked portions of the Schottky barrier metal and the overlayer therebeneath; (k) remove mask; (l) mask the remaining Schottky barrier metal for detector active areas; (m) remove the unmasked Schottky barrier metal; (n) remove mask; (o) mask for ohmic contact to overlayer and deposit ohmic contact; (p) strip mask; and (q) attach bonding leads to overlayer ohmic contact and to detector ohmic contacts.

Claim 4

A method of making an infrared detector from a semiconductor substrate doped slightly conductive, which method includes the following steps: (a) prepare the substrate and coat one side with an ohmic contact metal; (b) deposit a layer of semiconductor photoconductor material on the opposite side of said substrate from metal; (c) deposit atop said material an overlayer of the same material as the substrate; (d) mask the overlayer for detector ohmic contacts; (e) remove the unmasked portions of the overlayer and a portion of the photoconductor layer to form cavities therein; (f) deposit ohmic contact material atop the mask and onto the bottom of said cavities (g) remove the mask and the contact material thereon; (h) deposit a layer of Schottky barrier metal atop the overlayer and onto the walls and bottoms of said cavities; (i) mask for detector delineation; (j) remove the unmasked portions of the Schottky barrier metal and the overlayer therebeneath; (k) remove mask; (l) mask the remaining Schottky barrier metal for detector active areas; (m) remove the unmasked Schottky barrier metal; (n) remove mask; (o) mask for ohmic contact to overlayer and deposit ohmic contact; (p) strip mask; and (q) attach bonding leads to overlayer ohmic contact and to detector ohmic contacts.