Semiconductor device
AssigneeAgency of Industrial Science and Technology
InventorsKimihiro Ohta, Tadashi Nakagawa, Naoyuki Kawai, Takeshi Kojima, Mitsuo Kawashima
Life of this patent
Estimating the term…
Abstract
A semiconductor device comprises a superlattice semiconductor portion having a plurality of pairs of superlattice semiconductor thin films for forming step differences of band edge energy. The pairs of the thin films are laminated such that parameters which determine the structure of the thin films are monotonically changed in the direction of the lamination of the thin films. Electrodes are disposed to apply an electric field across both ends of the superlattice semiconductor portion. The semiconductor device has a good negative resistance characteristic and a large design freedom of semiconductor device.
Claims26
A semiconductor device comprising
- a superlattice semiconductor portion having first and second ends and including a plurality of laminated pairs of semiconductor thin films arranged along an axis perpendicular to the interface thereof thereby forming a potential profile along said axis determined by the stepped differences between the band edge energies of the thin films forming each of said pairs, said potential profile having virtual miniband and minigap energy states associated therewith and being defined by at least one of the thickness, chemical composition and dopant materials of said thin films, at least one of the thickness, chemical composition and dopant materials of said thin films being modulated in the direction of said axis whereby said miniband and minigap energy states are monotonically changed in the direction of said axis for every pair of said thin films;
- and
- electrodes coupled to the first and second ends of said superlattice semiconductor portion for applying an electric field thereacross.
A semiconductor device comprising
- a superlattice semiconductor portion having first and second ends including a plurality of laminated pairs of semiconductor thin films arranged along an axis perpendicular to the interfaces thereof forming a potential profile along said axis determined by the stepped differences between the band edge energies of the thin films forming each of said pairs, said potential profile having virtual miniband and minigap energy states associated therewith and being defined by at least one of the thickness, chemical composition and dopant materials of said thin films, at least one of the thickness, chemical composition and dopant materials of said thin films being modulated in the direction of said axis whereby said miniband and minigap energy states are monotonically changed in the direction of said axis for every pair of said thin films;
- electrodes coupled to the first and second ends of said superlattice semiconductor portion for applying an electric field thereacross;
- and
- an anti-reflection portion interposed between said superlattice semiconductor portion and at least one of said electrodes, one end portion of said anti-reflection portion in the vicinity of said superlattice semiconductor portion having a potential profile which is similar to the potential profile formed by said superlattice semiconductor portion, the other end of said anti-reflection portion having a uniform potential profile and the middle region between said one end and the other end of said anti-reflection portion having a potential profile which resides in the middle of said potential profiles in the end portions of said anti-reflection portion.
Dependencies are inferred from the claim text.