Abstract:
Methods of forming a nano-scale electronic and optoelectronic devices include forming a substrate having a semiconductor layer therein and a substrate insulating layer on the semiconductor layer. An etching template having a first array of non-photolithographically defined nano-channels extending therethrough, is formed on the substrate insulating layer. This etching template may comprise an anodized metal oxide, such as an anodized aluminum oxide (AAO) thin film. The substrate insulating layer is then selectively etched to define a second array of nano-channels therein. This selective etching step preferably uses the etching template as an etching mask to transfer the first array of nano-channels to the underlying substrate insulating layer, which may be thinner than the etching template. An array of semiconductor nano-pillars is then formed in the second array of nano-channels. The semiconductor nano-pillars in the array may have an average diameter in a range between about 8 nm and about 50 nm. The semiconductor nano-pillars are also preferably homoepitaxial or heteroepitaxial with the semiconductor layer.
Abstract:
A method for forming a modified semiconductor having a number of band gaps involves providing a semiconductor having a surface and a quantum region which emits photons in response to electrical or optical stimulation, the quantum region having an original band gap and being disposed under the surface and applying a number of layers of a number of materials to a number of selected regions of the surface, the materials being adapted to cause, upon thermal annealing, a number of different degrees of intermixing in a number of portions of the quantum region disposed immediately below each of the selected regions of the surface. The layers of materials can be applied in a dot or line pattern, or both, to increase the plurality of band gap tuning. The method includes thermally annealing the layers to the surface. The methods result in a modified semiconductor which exhibits a number of different band gaps in a number of portions of the quantum region depending upon the positioning of the layers of materials on the surface immediately above the respective portions of the quantum region.
Abstract:
A method of forming a semiconductor device includes the following steps: providing a plurality of semiconductor layers; providing means for coupling signals to and/or from layers of the device; providing a layer of quantum dots disposed between adjacent layers of the device; and providing an auxiliary layer disposed in one of the adjacent layers, and spaced from the layer of quantum dots, the auxiliary layer being operative to communicate carriers with the layer of quantum dots.
Abstract:
Disclosed is a method of forming a quantum dots array. In the method of the present invention, a structure of wire-like quantum dots with good quality is formed in materials having an inconsistency in the lattice constant on a tilted substrate by using the binding property of atomic bonding due to chemical bonding steps of the tilted substrate, and the spacing of the wire-like quantum dots is varied by using the step width of the tilted substrate which is transformed due to a partial pressure of a source gas and the thickness of a buffer layer. The invention allows materials having an inconsistency in the lattice constant to be freely formed in the form of quantum wires with a growing technique only and accordingly to be used as base materials in use for manufacture of novel concept of optoelectronic devices which have not been obtained so far.
Abstract:
A method of forming a semiconductor device includes the following steps: providing a plurality of semiconductor layers; providing means for coupling signals to and/or from layers of the device; providing a layer of quantum dots disposed between adjacent layers of the device; and providing an auxiliary layer disposed in one of the adjacent layers, and spaced from the layer of quantum dots, the auxiliary layer being operative to communicate carriers with the layer of quantum dots.
Abstract:
A method of forming a semiconductor device includes the following steps: providing a plurality of semiconductor layers; providing means for coupling signals to and/or from layers of the device; providing a quantum well disposed between adjacent layers of the device; and providing a layer of quantum dots disposed in one of the adjacent layers, and spaced from the quantum well, whereby carriers can tunnel in either direction between the quantum well and the quantum dots.
Abstract:
A method for manufacturing quantum wires is provided in which a stacked structure having AlAs layers and GaAs layers alternatively is formed, V-grooves are formed beside the GaAs layers and the quantum wires are formed using the V-grooves. The method for manufacturing quantum wires, which method includes the following steps: growing a GaAs buffer layer on the facet (011) of a GaAs single crystal substrate; growing an AlAs layer for using as oxide mask and a GaAs layer for a V-groove alternatively on the GaAs buffer layer so that each GaAs layer is stacked between an AlAs layer and an adjacent AlAs layer; growing the cover layer of GaAs on the AlAs layer which is grown as the top layer of the structure; cutting the entire structure including the GaAs cover layer to the perpendicular direction of (011), whose structure is grown in the orientation of (011) entirely, so as to expose the facet (100); performing a heat treatment for the entire structure cut to expose the facet (100) and forming oxide film on the exposed portion of each AlAs layer; etching each exposed GaAs layer chemically using the oxide as mask and forming V-groove so that the facet (111) of GaAs layer is exposed; and growing the quantum wire in the V-groove.
Abstract:
A mesoscopic structure is fabricated such that the desired dominant modes of the acoustic phonons in the structure have wavelengths such that the length of a half-integral number of wavelengths equals the length of the structure through which the desired electron wave is propagating. A manner of achieving this object is to provide for a material in a quantum wire and a material at the end of the quantum wire such that the two materials have such different properties (as disclosed hereinafter) to abruptly dampen the phonon modes at the interface between the two materials. With such an interface, a clamped boundary condition will occur and the modes of amplitude can be assumed to vanish at the interface. Such a case applies at some metal-semiconductor interfaces. In particular, for a mesoscopic device having wire-like regions which terminate on a variety of metal regions (regions used as contacts, gates, barriers, etc.), it is satisfactory to apply clamped boundary conditions. At these boundaries, the acoustic modes will have nodes instead of the anti-nodes that are established in the case of an open boundary.
Abstract:
In its gate region (10), a silicon MOS technology component has a surface structure (6) having edges and/or vertices at which inversion regions, suitable as quantum wires or quantum dots, are preferentially formed when a gate voltage is applied. The surface structure is preferably formed as a silicon pyramid (6) by local molecular beam epitaxy.
Abstract:
This invention describes a nanometer scale interband lateral resonant tunneling transistor, and the method for producing the same, with lateral geometry, good fanout properties and suitable for incorporation into large-scale integrated circuits. The transistor is of a single gate design and operation is based on resonant tunneling processes in narrow-gap nanostructures which are highly responsive to quantum phenomena. Such quantum-effect devices can have very high density, operate at much higher temperatures and are capable of driving other devices.