HEMT and method of adjusting electron density of 2DEG
AssigneeUnited Microelectronics Corp.
InventorsKai-Lin Lee, Zhi-Cheng Lee, Wei-Jen Chen
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Abstract
A high electron mobility transistor (HEMT) includes a gallium nitride layer. An aluminum gallium nitride layer is disposed on the gallium nitride layer, wherein the aluminum gallium nitride layer comprises a tensile stress. A source electrode and a drain electrode are disposed on the aluminum gallium nitride layer. A gate electrode is disposed on the aluminum gallium nitride layer between the source electrode and the drain electrode. At least one silicon oxide layer is embedded in the aluminum gallium nitride layer, wherein the silicon oxide layer is formed by a flowable chemical vapor deposition, and the silicon oxide layer increases the tensile stress in the aluminum gallium nitride layer.
Claims19
A high electron mobility transistor (HEMT), comprising:
- a gallium nitride layer;
- an aluminum gallium nitride layer disposed on the gallium nitride layer, wherein the aluminum gallium nitride layer comprises a tensile stress;
- a source electrode and a drain electrode disposed on the aluminum gallium nitride layer;
- a gate electrode disposed on the aluminum gallium nitride layer between the source electrode and the drain electrode;
- and
- a plurality of silicon oxide layers embedded in the aluminum gallium nitride layer, wherein each of the plurality of silicon oxide layers is free from protruding a top surface of the aluminum gallium nitride layer, sizes of the plurality of silicon oxide layers are the same, the plurality of silicon oxide layers are formed by a flowable chemical vapor deposition, and each of the plurality of silicon oxide layers increases the tensile stress in the aluminum gallium nitride layer.
A high electron mobility transistor (HEMT) comprising:
- a gallium nitride layer;
- an aluminum gallium nitride layer disposed on the gallium nitride layer, wherein the aluminum gallium nitride layer comprises a tensile stress;
- a source electrode and a drain electrode disposed on the aluminum gallium nitride layer;
- a gate electrode disposed on the aluminum gallium nitride layer between the source electrode and the drain electrode;
- and
- at least one stressor embedded in the aluminum gallium nitride layer, wherein the stressor decreases the tensile stress in the aluminum gallium nitride layer.
A method of adjusting an electron density of a two-dimensional electron gas (2DEG), comprising:
- providing a gallium nitride layer and an aluminum gallium nitride layer, wherein the aluminum gallium nitride layer contacts the gallium nitride layer, a source electrode, a drain electrode and a gate electrode are disposed on the aluminum gallium nitride layer, the aluminum gallium nitride layer comprises a tensile stress, and the 2DEG is formed within the gallium nitride layer;
- and
- performing a step selected from step A and step B, wherein:
- Step A comprises forming at least one silicon oxide layer embedded in the aluminum gallium nitride layer, wherein the silicon oxide layer is formed by a flowable chemical vapor deposition, the silicon oxide layer increases the tensile stress in the aluminum gallium nitride layer and increases an electron density of the 2DEG;
- Step B comprises forming at least one stressor embedded in the aluminum gallium nitride layer, wherein the stressor decreases the tensile stress in the aluminum gallium nitride layer and decreases the electron density of the 2DEG.
Dependencies are inferred from the claim text.