Ordered mixed crystal semiconductor superlattice device
AssigneeFujitsu Limited
InventorsYoshiaki Nakata, Osamu Ueda, Satoshi Nakamura
Life of this patent
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Abstract
On a substrate having a surface slightly tilted by an angle .alpha. within the range of from 0.5 to 10 degrees from the (110) plane in the <00-1> direction, a superlattice structure having a periodicity in both <110> and <001> directions is formed. Various band structures are possible by selecting an appropriate constituent material and periodicity for the superlattice structure. When current flows in a direction without periodicity, a very high mobility is obtained as a result of suppressed alloy scattering. If current is caused to flow in a direction with periodicity, and the periodicity is properly selected, optical phonon scattering can also be suppressed.
Claims17
A semiconductor device comprising a charge carrier flow region having a superlattice structure, said superlattice structure comprising two or more discrete monomolecular layers of different binary group III-V compounds disposed in periodically ordered relationship in <110>
- and <001>
- directions, said device further including a substrate having a surface on which said superlattice structure is formed, said surface being tilted from the (110) plane in the <00-1>
- direction.
A semiconductor device comprising:
- a semiconductor substrate having a tilted surface;
- and
- a superlattice structure formed on said surface and having an ordered periodicity in the tilted direction, said structure being such that the width of a miniband of the highest energy having electrons therein is narrower than the energy of an optical phonon, and the energy of a forbidden band therein between said miniband of the highest energy having electrons and a miniband of the lowest energy without electrons therein is higher than the energy of the optical phonon, said surface being tilted from the (110) plane in the <00-1>
- direction.
Dependencies are inferred from the claim text.