USA As Represented by Secretary of the Navy

Alan G Jacobs

Boris N Feigelson

Travis J Anderson

Marko J Tadjer

James C Gallagher

Francis J Kub

Karl D Hobart

James A Wollmershauser

Benjamin L Greenberg

Kevin P Anderson

Andrew D Koehler

Daniel G Georgiev

Matthew Porter

Mona A Ebrish

Prakash Pandey

Tolen Michael Nelson

Raghav Khanna

Michael Robert Hontz

A technique for selective-area diffusion doping of III-N epitaxial material layers and for fabricating power device structures utilizing this technique. Dopant species such as Mg are introduced into the III-N material layer and are diffused into the III-N material by annealing under stable or metastable conditions. The dopant species can be introduced via deposition of a metal or alloy layer containing such species using sputtering, e-beam evaporation or other technique known to those skilled in the art. The dopant material layer is capped with a thermally stable layer to prevent decomposition and out-diffusion, and then is annealed under stable or metastable conditions to diffuse the dopant into the III-N material GaN without decomposing the surface.

Selective area diffusion doping of III-N materials

A hybrid edge termination structure and method of forming the same. The hybrid edge termination structure in accordance with the invention is based on a junction termination extension (JTE) architecture, but includes an additional Layer of guard ring (GR) structures to further implement the implantation of dopants into the structure. The hybrid edge termination structure of the invention has a three-Layer structure, with a top Layer and a bottom Layer each having a constant dopant concentration in the lateral direction, and a middle Layer consisting of a plurality of spatially defined alternating regions that exhibit the electrical properties of either the top or bottom layer. By including the second layer, a discretized varying charge profile can be obtained that approximates the varying charge profile obtained using tapered edge termination but with easier manufacturing and lower cost.

Multi-layer hybrid edge termination for III-N power devices

RF susceptors manufactured by means of 3D printing. 3D-printed susceptors in accordance with the invention include susceptors having solid or mesh walls, where the susceptors are in the form of hollow cylinders, pyramids, spheres, hemispheres, ellipsoids, paraboloids, toroids, or prisms; flat planes; or other hollow or solid three-dimensional shapes. The 3D-printed susceptors can be formed from any suitable starting material, such as tungsten powder, graphite, silicon carbide, molybdenum powder, tantalum powder, rhenium powder, or alloys thereof, or can be formed such that some portions of the susceptors are formed from one or more materials while other portions are formed from different material(s).

3D printed susceptor for rapid indirect RF heating

Methods for efficient doping of wide-bandgap (WBG) and ultrawide-bandgap (UWBG) semiconductors by implantation, and WBG and UWBG semiconductors made using the disclosed methods. A p-type semiconductor region is formed by implanting specified acceptor and donor co-dopant atoms in a predetermined ratio, e.g., two acceptors to one donor (ADA), into the semiconductor lattice. An n-type type semiconductor region is by implanting specified donor and acceptor co-dopant atoms in a predetermined ratio, e.g., two donors to one acceptor (DAD), into the semiconductor lattice. Compensator atoms are also implanted into the lattice to complete formula units in the crystal lattice structure and preserve the stoichiometry of the semiconductor material. The doped material is then annealed to activate the dopants and repair any damage to the lattice that might have occurred during implantation.

WBG and UWBG semiconductor with p- and n-type conductivity and process for making the same

Thermoelectric (TE) nanocomposite material that includes at least one component consisting of nanocrystals. A TE nanocomposite material in accordance with the present invention can include, but is not limited to, multiple nanocrystalline structures, nanocrystal networks or partial networks, or multi-component materials, with some components forming connected interpenetrating networks including nanocrystalline networks. The TE nanocomposite material can be in the form of a bulk solid having semiconductor nanocrystallites that form an electrically conductive network within the material. In other embodiments, the TE nanocomposite material can be a nanocomposite thermoelectric material having one network of p-type or n-type semiconductor domains and a low thermal conductivity semiconductor or dielectric network or domains separating the p-type or n-type domains that provides efficient phonon scattering to reduce thermal conductivity while maintaining the electrical properties of the p-type or n-type semiconductor.

Thermoelectric nanocomposite materials

A method for activating implanted dopants and repairing damage to dopant-implanted GaN to form n-type or p-type GaN. A GaN substrate is implanted with n- or p-type ions and is subjected to a high-temperature anneal to activate the implanted dopants and to produce planar n- or p-type doped areas within the GaN having an activated dopant concentration of about 10-10cm. An initial annealing at a temperature at which the GaN is stable at a predetermined process temperature for a predetermined time can be conducted before the high-temperature anneal. A thermally stable cap can be applied to the GaN substrate to suppress nitrogen evolution from the GaN surface during the high-temperature annealing step. The high-temperature annealing can be conducted under Npressure to increase the stability of the GaN. The annealing can be conducted using laser annealing or rapid thermal annealing (RTA).

GaN devices with ion implanted ohmic contacts and method of fabricating devices incorporating the same

An enhanced symmetric multicycle rapid thermal annealing process for removing defects and activating implanted dopant impurities in a III-nitride semiconductor sample. A sample is placed in an enclosure and heated to a temperature Tunder an applied pressure Pfor a time t. While the heating of the sample is maintained, the sample is subjected to a series of rapid laser irradiations under an applied pressure Pand a baseline temperature T. Each of the laser irradiations heats the sample to a temperature Tabove its thermodynamic stability limit. After a predetermined number of temperature pulses or a predetermined period of time, the laser irradiations are stopped and the sample is brought to a temperature Tand held at Tfor a time tto complete the annealing.

Growing community of inventors

Arlington, VA, United States of America

Alan G Jacobs