Tunnel emitter upper valley transistor
AssigneeInternational Business Machines Corporation
InventorsWilliam P. Dumke, Alan B. Fowler
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Abstract
The invention is a three-terminal transistor structure having five layers of materials that in combination provide conduction by high mobility carrier transport across the base in an energy valley above the conduction band. The conduction is by majority carrier tunneling injection from the emitter and transport at an upper valley level across the base. The resulting structure is capable of switching in times of 10.sup.-12 seconds.
Claims9
A transistor of the type having emitter, base and collector regions of layers of epitaxial monocrystalline semiconductor material, the improvement for tunneling injection carrier transport comprising:
- an energy relationship between said base region and said emitter region whereby an upper valley energy level in said base is essentially equivalent to a normal energy level in said emitter,
- an emitter barrier having an energy level higher than said normal energy level in said emitter and having a thickness for quantum mechanical tunneling, and
- a collector barrier higher than the level of normal electrons in said base.
A transistor having an emitter, a base and a collector comprising in combination:
- a base region of a doped crystallographically oriented semiconductor material having an upper valley energy state of a first value,
- an emitter region of doped crystallographically oriented semiconductor material epitaxial with said base and having a normal energy state essentially at said first level and further separated from said base by a barrier higher than said first level and of a distance compatible with quantum mechanical tunneling and
- a collector region of doped crystallographically oriented semiconductor material epitaxial with said base and having a normal energy state that is lower than said first level and having a barrier adjacent to said base.
A transistor having emitter and collector regions separated by a base region in a crystallographically oriented monocrystalline semiconductor material body, said emitter having a region with a normal energy level of a particular level separated from said base region by an emitter barrier region having a height greater than said particular level and a distance compatible with quantum mechanical tunneling.
- said base region having an upper energy valley at said particular level and a thickness distance allowing rapid transport across said base and a low resistance resulting from normal carriers present therein, and
- said collector having a region with a normal energy level lower than said particular level separated from said base region by a barrier.
Dependencies are inferred from the claim text.