High electron mobility transistor (HEMT) device and method of making the same
AssigneeQorvo US, Inc.
InventorsEdward A. Beam, III, Jinqiao Xie
Life of this patent
Estimating the term…
Abstract
A high electron mobility transistor (HEMT) device with epitaxial layers that include a gallium nitride (GaN) layer co-doped with silicon (Si) and germanium Ge and a method of making the same is disclosed. The HEMT device includes a substrate with epitaxial layers over the substrate. An n-type gallium nitride (GaN) layer is disposed on an interface surface of the epitaxial layers, wherein the n-type GaN layer is co-doped with silicon (Si) and germanium (Ge) that provide a carrier concentration of at least 1×1020 cm−3 and a root mean square (RMS) surface roughness that is no greater than 2 nm for a contact surface of the n-type GaN layer that is interfaced with the interface surface of the epitaxial layers.
Claims20
A high electron mobility transistor (HEMT) device comprising:
- a substrate;
- epitaxial layers over the substrate;
- and
- an n-type gallium nitride (GaN) layer disposed on an interface surface of the epitaxial layers, wherein the n-type GaN layer is co-doped with silicon (Si) and germanium (Ge) that provide a carrier concentration of at least 1×1020 cm−3 and a root mean square (RMS) surface roughness that is no greater than 2 nm for a contact surface of the n-type GaN layer that is interfaced with the interface surface of the epitaxial layers.
A method of making a high electron mobility transistor (HEMT) device comprising:
- providing a substrate;
- disposing epitaxial layers onto the substrate;
- masking the epitaxial layers with an etch mask;
- etching a source contact recess and a drain contact recess to expose an interface surface on the epitaxial layers, wherein the source contact recess and the drain contact recess are spaced apart;
- disposing an n-type GaN layer within the source contact recess and the drain contact recess;
- and
- co-doping the n-type GaN layer with both silicon (Si) and germanium (Ge) to form a source contact within the source contact recess and form a drain contact within the drain contact recess such that the source contact and the drain contact each have a carrier concentration of at least 1×1020 cm−3 and a root mean square (RMS) surface roughness that is no greater than 2 nm for a contact surface of the n-type GaN layer that is interfaced with the interface surface of the epitaxial layers.
Dependencies are inferred from the claim text.