Cree Gmbh

USA As Represented by Secretary of the Navy

Wolfspeed, Inc.

Michael O'Loughlin

Joseph John Sumakeris

David T Emerson

Michael John Bergmann

James Ibbetson

Kathleen Marie Doverspike

Amber Christine Abare

Howard Dean Nordby, Jr

Anant Kumar Agarwal

Michael James Paisley

Lin Cheng

Adrian Powell

Albert Augustus Burk, Jr

Al Burk

John Williams Palmour

Qingchun Zhang

Alexander V Suvorov

Doyle Craig Capell

Howard Nordby

Albert Burk

Michael Paisley

Stabilized, high-doped silicon carbide is described. A silicon carbide crystal is grown on a substrate using chemical vapor deposition so that the silicon carbide crystal includes a dopant and the strain compensating component. The strain compensating component can be an isoelectronic element and/or an element with the same majority carrier type as the dopant. The silicon carbide crystal can then be cut into silicon carbide wafers. In some embodiments, the dopant is n-type and the strain compensating component is selected from a group comprising germanium, tin, arsenic, phosphorus, and combinations thereof. In some embodiments, the strain compensating component comprises germanium and the dopant is nitrogen.

Stabilized, high-doped silicon carbide

A semiconductor die and a process for fabricating the semiconductor die are disclosed. The semiconductor die has a substrate and a silicon carbide (SiC) epitaxial structure on the substrate. The SiC epitaxial structure includes at least a first N-type SiC layer, at least a first P-type SiC layer, and carbon vacancy reduction material, which has been implanted into a surface of the SiC epitaxial structure. Further, the SiC epitaxial structure has been annealed to mobilize the carbon vacancy reduction material to diffuse carbon atoms substantially throughout the SiC epitaxial structure, thereby increasing an average carrier lifetime in the SiC epitaxial structure.

Using a carbon vacancy reduction material to increase average carrier lifetime in a silicon carbide semiconductor device

Single crystal silicon carbide epitaxial layer on an off-axis substrate are manufactured by placing the substrate in an epitaxial growth reactor, growing a first layer of epitaxial silicon carbide on the substrate, interrupting the growth of the first layer of epitaxial silicon carbide, etching the first layer of epitaxial silicon carbide to reduce the thickness of the first layer, and regrowing a second layer of epitaxial silicon carbide on the first layer of epitaxial silicon carbide. Carrot defects may be terminated by the process of interrupting the epitaxial growth process, etching the grown layer and regrowing a second layer of epitaxial silicon carbide. The growth interruption/etching/regrowth may be repeated multiple times. A silicon carbide epitaxial layer has at least one carrot defect that is terminated within the epitaxial layer. A semiconductor stricture includes an epitaxial layer of silicon carbide on an off-axis silicon carbide substrate, and a carrot defect having a nucleation point in the vicinity of an interface between the substrate and the epitaxial layer and is terminated within the epitaxial layer.

Reduction of carrot defects in silicon carbide epitaxy

The present disclosure relates to a Silicon Carbide (SiC) semiconductor device having both a high blocking voltage and low on-resistance. In one embodiment, the semiconductor device has a blocking voltage of at least 10 kilovolts (kV) and an on-resistance of less than 10 milli-ohms centimeter squared (m&#x3a9;&#xb7;cm) and even more preferably less than 5 m&#x3a9;&#xb7;cm. In another embodiment, the semiconductor device has a blocking voltage of at least 15 kV and an on-resistance of less than 15 m&#x3a9;&#xb7;cmand even more preferably less than 7 m&#x3a9;&#xb7;cm. In yet another embodiment, the semiconductor device has a blocking voltage of at least 20 kV and an on-resistance of less than 20 m&#x3a9;&#xb7;cmand even more preferably less than 10 m&#x3a9;&#xb7;cm. The semiconductor device is preferably, but not necessarily, a thyristor such as a power thyristor, a Bipolar Junction Transistor (BJT), an Insulated Gate Bipolar Transistor (IGBT), or a PIN diode.

SiC devices with high blocking voltage terminated by a negative bevel

A semiconductor device is provided that includes a Group III nitride based superlattice and a Group III nitride based active region comprising at least one quantum well structure on the superlattice. The quantum well structure includes a well support layer comprising a Group III nitride, a quantum well layer comprising a Group III nitride on the well support layer and a cap layer comprising a Group III nitride on the quantum well layer. A Group III nitride based semiconductor device is also provided that includes a gallium nitride based superlattice having at least two periods of alternating layers of InGaN and InGaN, where 0&#x2266;X&#x3c;1 and 0&#x2266;Y&#x3c;1 and X is not equal to Y. The semiconductor device may be a light emitting diode with a Group III nitride based active region. The active region may be a multiple quantum well active region.

Group III nitride based light emitting diode structures with a quantum well and superlattice, group III nitride based quantum well structures and group III nitride based superlattice structures

A silicon carbide-based power device includes a silicon carbide drift layer having a planar surface that forms an off-axis angle with a &#x3c;0001&#x3e; direction of less than 8&#xb0;.

Stable power devices on low-angle off-cut silicon carbide crystals

Parasitic deposits are controlled in a deposition system for depositing a film on a substrate, the deposition system of the type defining a reaction chamber for receiving the substrate and including a process gas in the reaction chamber and an interior surface contiguous with the reaction chamber. Such control is provided by flowing a buffer gas between the interior surface and at least a portion of the process gas to form a gas barrier layer such that the gas barrier layer inhibits contact between the interior surface and components of the process gas. A deposition system for depositing a film on a substrate using a process gas includes a reaction chamber adapted to receive the substrate and the process gas. The system further includes an interior surface contiguous with the reaction chamber. A buffer gas supply system is adapted to supply a flow of a buffer gas between the interior surface and at least a portion of the process gas such that the flow of the buffer gas forms a gas barrier layer to inhibit contact between the interior surface and components of the process gas when the process gas is disposed in the reaction chamber.

Deposition systems and susceptor assemblies for depositing a film on a substrate

A light emitting diode is provided having a Group III nitride based superlattice and a Group III nitride based active region on the superlattice. The active region has at least one quantum well stricture. The quantum well structure includes a first Group III nitride based barrier layer, a Group III nitride based quantum well layer on the first barrier layer and a second Group III nitride based barrier layer. A Group III nitride based semiconductor device and methods of fabricating a Group III nitride based semiconductor device having an active region comprising at least one quantum well structure are provided. The quantum well structure includes a well support layer comprising a Group III nitride, a quantum well layer comprising a Group III nitride on the well support layer and a cap layer comprising a Group III nitride on the quantum well layer. A Group III nitride based semiconductor device is also provided that includes a gallium nitride based superlattice having at least two periods of alternating layers of InGaN and InGaN, where 0&#x2266;X&#x3c;1 and 0&#x2266;Y&#x3c;1 and X is not equal to Y. The semiconductor device may be a light emitting diode with a Group III nitride based active region. The active region may be a multiple quantum well active region.

Methods of fabricating group III nitride based light emitting diode structures with a quantum well and superlattice, group III nitride based quantum well structures and group III nitride based superlattice structures

A method for locally controlling the stoichiometry of an epitaxially deposited layer on a semiconductor substrate is provided. The method includes directing a first reactant gas and a doping gas across a top surface of a semiconductor substrate and directing a drive gas and a second reactant gas against the substrate separately from the first reactant gas in a manner that rotates the substrate while introducing the second reactant gas at an edge of the substrate to control each reactant separately, thereby compensating and controlling depletion effects and improving doping uniformity in resulting epitaxial layers on the substrate.

Directed reagents to improve material uniformity

A light emitting diode is provided having a Group III nitride based superlattice and a Group III nitride based active region on the superlattice. The active region has at least one quantum well structure. The quantum well structure includes a first Group III nitride based barrier layer, a Group III nitride based quantum well layer on the first barrier layer and a second Group III nitride based barrier layer. A Group III nitride based semiconductor device and methods of fabricating a Group III nitride based semiconductor device having an active region comprising at least one quantum well structure are provided. The quantum well structure includes a well support layer comprising a Group III nitride, a quantum well layer comprising a Group III nitride on the well support layer and a cap layer comprising a Group III nitride on the quantum well layer. A Group III nitride based semiconductor device is also provided that includes a gallium nitride based superlattice having at least two periods of alternating layers of InGaN and InGaN, where 0&#x2266;X&#x3c;1 and 0&#x2266;Y&#x3c;1 and X is not equal to Y. The semiconductor device may be a light emitting diode with a Group III nitride based active region. The active region may be a multiple quantum well active region.

Group III nitride based superlattice structures

Single crystal silicon carbide epitaxial layer on an off-axis substrate are manufactured by placing the substrate in an epitaxial growth reactor, growing a first layer of epitaxial silicon carbide on the substrate, interrupting the growth of the first layer of epitaxial silicon carbide, etching the first layer of epitaxial silicon carbide to reduce the thickness of the first layer, and regrowing a second layer of epitaxial silicon carbide on the first layer of epitaxial silicon carbide. Carrot defects may be terminated by the process of interrupting the epitaxial growth process, etching the grown layer and regrowing a second layer of epitaxial silicon carbide. The growth interruption/etching/regrowth may be repeated multiple times. A silicon carbide epitaxial layer has at least one carrot defect that is terminated within the epitaxial layer. A semiconductor structure includes an epitaxial layer of silicon carbide on an off-axis silicon carbide substrate, and a carrot defect having a nucleation point in the vicinity of an interface between the substrate and the epitaxial layer and is terminated within the epitaxial layer.

A method for controlling parasitic deposits in a deposition system for depositing a film on a substrate, the deposition system defining a reaction chamber for receiving the substrate and including a process gas in the reaction chamber and an interior surface contiguous with the reaction chamber, includes flowing a buffer gas between the interior surface and at least a portion of the process gas to form a gas barrier layer such that the gas barrier layer inhibits contact between the interior surface and components of the process gas.

Growing community of inventors

Chapel Hill, NC, United States of America

Michael O'Loughlin