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AssigneeAgency for Science, Technology and Research
InventorsBenzhong Wang, Soo Jin Chua
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A method for the production of a semiconductor structure having self-organized quantum wires is described. The process includes the formation of multi-atomic steps on a (001) oriented semiconductor substrate inclined at an angle toward the [110] direction. Quantum wires are then spontaneously formed in situ along edges of the multi-atomic steps during epitaxial growth of a semiconductor with a larger or smaller lattice constant than the substrate but with a band gap narrower than that of the underlying material. Further deposition of a layer of semiconductor with a lattice constant within 1% of the substrate but with a band gap wider than that of the wire material then buries the quantum wires between this layer and the substrate layers. These layers are free of defects. Crystal and energy level structures of the quantum wire such as linear density, lateral and vertical dimension, and emission wavelength of photoluminescence can be easily controlled by selecting the angle of inclination of the substrate, lattice mismatch and different combinations of materials. A semiconductor laser with the active layer comprising quantum wires made by this method is also disclosed.
A method of fabricating a semiconductor structure having self-organised quantum wires, comprising:
The method of any preceding claim wherein the fourth semiconductor is chosen to have a lattice mismatch of less than 1.0% with the first semiconductor.
The method of any preceding claim wherein the third semiconductor has a lattice mismatch of at least 2.5% with the first semiconductor.
The method of any preceding claim wherein the first semiconductor is GaAs.
The method of any preceding claim wherein the second and fourth semiconductors are selected from the group consisting of compound semiconductors formed from group III and group V elements and compound semiconductors formed from group II and group VI elements.
The method of any preceding claim wherein the third semiconductor is selected from the group consisting of binary and ternary compound semiconductors formed from group III and group V elements and binary and ternary compound semiconductors formed from group II and group VI elements.
The method of any preceding claim wherein the second, third and fourth semiconductors are deposited by a growth technique selected from the group consisting of MOCVD, GSMBE, VPE, CBE and MBE.
The method of any preceding claim wherein the third semiconductor is grown at a temperature in the range of 380 to 580° C.
The method of any preceding claim where the growth rate of the third semiconductor is no more than 2 Å/s.
The method of any preceding claim wherein the third semiconductor is grown to a thickness of from 0.3 to 3.0 nm.
A semiconductor device comprising:
Dependencies are inferred from the claim text.