A transistor having high field-effect mobility is provided. In order that an oxidesemiconductor layer through which carriers flow is not in contact with a gate insulating film, a buried channel structure in which the oxidesemiconductor layer through which carriers flow is separated from the gate insulating film is employed. Specifically, an oxidesemiconductor layer having high conductivity is provided between two oxide semiconductorlayers. Further, an impurity element is added to the oxide semiconductor layer in a self-aligned manner so that the resistance of a region in contact with an electrode layer is reduced. Further, the oxide semiconductor layer in contact with the gate insulating layer has a larger thickness than the oxide semiconductor layer having high conductivity.
The present invention provides a device structure and method of forming a finFet device having stacked fins. The method of the present invention comprises: providing a substrate with a first semiconductor layer on a first insulator layer, a second insulator layer on the first semiconductor layer, and a second semiconductor layer on the second insulator layer; forming a first fin and a second fin in the second semiconductor layer; masking the first fin; and forming a third fin in the first semiconductor layer, where the second fin is stacked on the third fin. The structure of the present invention comprises: a semiconductor substrate having a first semiconductor layer on a first insulator layer, a second insulator layer on the first semiconductor layer, and a second semiconductor layer on the second insulator layer; a first and second fin formed in the second semiconductor layer; and a third fin formed in the first semiconductor layer, where the second fin is stacked on the third fin.
Light emitting devices include an active region comprising a plurality of layers and a pit opening region on which the active region is disposed. The pit opening region is configured to expand a size of openings of a plurality of pits to a size sufficient for the plurality of layers of the active region to extend into the pits. In some embodiments, the active region comprises a plurality of quantum wells. The pit opening region may comprise a superlattice structure. The pits may surround their corresponding dislocations and the plurality of layers may extend to the respective dislocations. At least one of the pits of the plurality of pits may originate in a layer disposed between the pit opening layer and a substrate on which the pit opening layer is provided. The active region may be a Group III nitride based active region. Methods of fabricating such devices are also provided.
A high electron mobility transistor is disclosed which has a main semiconductor region formed on a silicon substrate. The main semiconductor region is a lamination of a buffer layer on the substrate, an electron transit layer on the buffer layer, and an electron supply layer on the electron transit layer. A source, drain, and gate overlie the electron supply layer. Also formed on the electron supply layer is a surface-stabilizing organic semiconductoroverlay which is of p conductivity type in contrast to the n type of the electron supply layer.