Recessed memory cell access devices and gate electrodes
First Claim
Patent Images
1. A gate electrode, comprising:
- a first gate material at least partially within a trench in a semiconductor substrate, the trench lined with a gate-oxide, the first gate material comprising doped polysilicon and having a first work function;
a second gate material at least partially within the trench and underlying the first gate material, the second gate material comprising another doped polysilicon and having a second work function different from the first work function; and
a separator between the doped polysilicon and the another doped polysilicon, the separator comprising a metal region.
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Abstract
Recessed access transistor devices used with semiconductor devices may include gate electrodes having materials with multiple work functions, materials that are electrically isolated from each other and supplied with two or more voltage supplies, or materials that create a diode junction within the gate electrode.
116 Citations
19 Claims
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1. A gate electrode, comprising:
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a first gate material at least partially within a trench in a semiconductor substrate, the trench lined with a gate-oxide, the first gate material comprising doped polysilicon and having a first work function; a second gate material at least partially within the trench and underlying the first gate material, the second gate material comprising another doped polysilicon and having a second work function different from the first work function; and a separator between the doped polysilicon and the another doped polysilicon, the separator comprising a metal region. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A recessed access device, comprising:
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at least one trench in a semiconductor substrate; an oxide material positioned on sidewalls and a bottom portion of the at least one trench; a P+ doped gate material vertically overlying the bottom portion of the at least one trench and physically isolated from the semiconductor substrate by at least a portion of the oxide material; an N+ doped gate material in the at least one trench and vertically overlying the P+ doped gate material; another material between the N+ doped gate material and the P+ doped gate material, the another material comprising at least one of a nitride, an oxide, a silicide, a conductive metal, and a metallic alloy; and an insulator cap vertically overlying the N+ doped gate material. - View Dependent Claims (14, 15, 16, 17, 18)
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19. A recessed access device, comprising:
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at least one trench in a semiconductor substrate; an oxide material positioned on sidewalls and a bottom portion of the at least one trench; a first gate material in the at least one trench and adjacent to at least a portion of the sidewalls of the at least one trench, the first gate material comprising one of an N+ doped gate material and a P+ doped gate material; a second gate material vertically overlying the bottom portion of the at least one trench, vertically underlying the first gate material, and physically isolated from the semiconductor substrate by at least a portion of the oxide material, the second gate material comprising a different one of the N+ doped gate material and the P+ doped gate material than the first gate material; a separator between the first gate material and the second gate material, the separator comprising at least one of a nitride, an oxide, a silicide, a conductive metal, and a metallic alloy; and an insulator cap vertically overlying the first gate material and second gate material.
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Specification