Showing papers by "Adam William Saxler published in 2008"

Thick nitride semiconductor structures with interlayer structures and methods of fabricating thick nitride semiconductor structures

Abstract: A semiconductor structure includes a substrate, a nucleation layer on the substrate, a compositionally graded layer on the nucleation layer, and a layer of a nitride semiconductor material on the compositionally graded layer. The layer of nitride semiconductor material includes a plurality of substantially relaxed nitride interlayers spaced apart within the layer of nitride semiconductor material. The substantially relaxed nitride interlayers include aluminum and gallium and are conductively doped with an n-type dopant, and the layer of nitride semiconductor material including the plurality of nitride interlayers has a total thickness of at least about 2.0 μm.

Nitride semiconductor structures with interlayer structures and methods of fabricating nitride semiconductor structures with interlayer structures

Abstract: A semiconductor structure includes a first layer of a nitride semiconductor material, a substantially unstrained nitride interlayer on the first layer of nitride semiconductor material, and a second layer of a nitride semiconductor material on the nitride interlayer. The nitride interlayer has a first lattice constant and may include aluminum and gallium and may be conductively doped with an n-type dopant. The first layer and the second layer together have a thickness of at least about 0.5 µm. The nitride semiconductor material may have a second lattice constant, such that the first layer may be more tensile strained on one side of the nitride interlayer than the second layer may be on the other side of the nitride interlayer.

Semiconductor devices including implanted regions and protective layers

Abstract: A semiconductor structure includes a Group III-nitride semiconductor layer, a protective layer on the semiconductor layer, a distribution of implanted dopants within the semiconductor layer, and an ohmic contact extending through the protective layer to the semiconductor layer.

Highly uniform group III nitride epitaxial layers on 100 millimeter diameter silicon carbide substrates

Abstract: A semiconductor structure is disclosed that includes a silicon carbide wafer having a diameter of at least 100 mm with a Group III nitride heterostructure on the wafer that exhibits high uniformity in a number of characteristics. These include: a standard deviation in sheet resistivity across the wafer less than three percent; a standard deviation in electron mobility across the wafer of less than 1 percent; a standard deviation in carrier density across the wafer of no more than about 3.3 percent; and a standard deviation in conductivity across the wafer of about 2.5 percent.

Methods of Fabricating Transistors Having Buried N-Type and P-Type Regions Beneath the Source Region

Abstract: High electron mobility transistors are provided that include a non-uniform aluminum concentration AlGaN based cap layer having a high aluminum concentration adjacent a surface of the cap layer that is remote from the barrier layer on which the cap layer is provided. High electron mobility transistors are provided that include a cap layer having a doped region adjacent a surface of the cap layer that is remote from the barrier layer on which the cap layer is provided. Graphitic BN passivation structures for wide bandgap semiconductor devices are provided. SiC passivation structures for Group III-nitride semiconductor devices are provided. Oxygen anneals of passivation structures are also provided. Ohmic contacts without a recess are also provided.

Methods of passivating surfaces of wide bandgap semiconductor devices

Abstract: High electron mobility transistors are provided that include a non-uniform aluminum concentration AlGaN based cap layer having a high aluminum concentration adjacent a surface of the cap layer that is remote from the barrier layer on which the cap layer is provided. High electron mobility transistors are provided that include a cap layer having a doped region adjacent a surface of the cap layer that is remote from the barrier layer on which the cap layer is provided. Graphitic BN passivation structures for wide bandgap semiconductor devices are provided. SiC passivation structures for Group III-nitride semiconductor devices are provided. Oxygen anneals of passivation structures are also provided. Ohmic contacts without a recess are also provided.

Structures semi-conductrices épaisses au nitrure, comprenant des structures de couche intermédiaires, et procédés de fabrication de structures semi-conductrices épaisses au nitrure

Abstract: L'invention concerne une structure semi-conductrice comprenant un substrat, une couche de nucleation sur le substrat, une couche a gradient de composition sur la couche de nucleation, et une couche d'un materiau semi-conducteur au nitrure sur la couche a gradient de composition. La couche d'un materiau semi-conducteur au nitrure comprend une pluralite de couches intermediaires au nitrure essentiellement relâchees reparties sur la couche d'un materiau semi-conducteur au nitrure. Les couches intermediaires au nitrure essentiellement relâchees comprennent de l'aluminium et du gallium, et sont dopees par conduction avec un dopant de type n, et la couche d'un materiau semi-conducteur au nitrure comportant la pluralite de couches intermediaires au nitrure a une epaisseur totale d'au moins environ 2,0 µm.

Deckschichten beinhaltend Aluminiumnitrid für Nitrid-basierte Transistoren und Verfahren zu deren Herstellung

Abstract: Es werden superschnelle Transistoren (High Electron Mobility Transistors) offenbart, die eine AlGaN-basierte Deckschicht mit ungleichmasiger Aluminiumkonzentration enthalten, die eine hohe Aluminiumkonzentration benachbart einer Oberflache der Deckschicht aufweist, die von der Sperrschicht entfernt ist, an der die Deckschicht vorgesehen ist. Es werden superschnelle Transistoren offenbart, die eine Deckschicht mit einer dotierten Region benachbart einer Oberflache der Deckschicht enthalten, die von der Sperrschicht entfernt ist, an der die Deckschicht vorgesehen ist. Es werden Graphit-BN-Passivierungsstrukturen fur Halbleitervorrichtungen mit einer grosen Bandlucke offenbart. Es werden SiC-Passivierungsstrukturen fur Gruppe III-Nitrid-Halbleitervorrichtungen offenbart. Es wird auch ein Sauerstoffanlassen der Passivierungsstrukturen offenbart. Es werden auch Ohmsche Kontakte ohne eine Vertiefung offenbart.