GaN Gate Oxide Interface Control Using Non-Plasma Oxidation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing methods for manufacturing switching devices with gallium nitride semiconductor layers suffer from the formation of gallium oxide layers at the interface between the semiconductor and the gate insulation film, leading to high interface states and reduced device performance due to exposure to oxidizing gases in a plasma state during the formation of the gate insulation film.
Innovation Solution
The method involves forming a gate insulation film made of silicon oxide using an oxidizing gas in a non-plasma state, such as ozone, to prevent oxidation of the gallium nitride semiconductor layer, thereby avoiding the formation of a gallium oxide layer at the interface or limiting its thickness to 1 nanometer or less, which reduces interface states and enhances device capability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If oxygen plasma is used to form the gate insulation film, then the gate insulation film can be formed effectively, but gallium oxide layer forms at the interface causing high interface states and reduced device performance
Solution Approach 1:
The patent changes the physical state parameter of the oxidizing gas from plasma state to non-plasma state (molecular state). This parameter change prevents the formation of gallium oxide layer at the interface while still enabling effective gate insulation film formation, thereby resolving the contradiction between manufacturing precision and device performance reliability
Solution Approach 2:
The patent creates an inert processing environment by using non-plasma oxidizing gas conditions that do not aggressively oxidize the gallium nitride semiconductor surface. This inert-like environment prevents harmful gallium oxide formation while allowing controlled silicon oxide film deposition, thus improving both interface quality and device performance
2Ease of manufacture
If oxidizing gas in plasma state is used during gate insulation film formation, then the film formation process is effective, but interface states increase due to gallium oxide layer formation
Solution Approach 1:
The patent modifies the oxidation condition parameter from plasma state to non-plasma state. This change maintains the film formation effectiveness by still providing oxidizing capability while eliminating the excessive oxidation that creates interface states, thus resolving the contradiction between ease of manufacture and manufacturing precision
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in a switching device with improved channel mobility by minimizing interface states, as demonstrated by channel mobility measurements exceeding 250 cm2Ns, compared to devices formed using methods with oxygen plasma, which achieve around 56 cm2Ns.
Implementation Method 1
forming a gate insulation film made of silicon oxide using an oxidizing gas in a non-plasma state, such as ozone
Implementation Method 2
to prevent oxidation of the gallium nitride semiconductor layer, thereby avoiding the formation of a gallium oxide layer at the interface
Data Source
AI summary
A switching includes a gallium nitride semiconductor and a gate insulation film. The gate insulation film is made of silicon oxide and disposed above the gallium nitride semiconductor layer. An interface between the gallium nitride insulation film and the gate insulation film is either free of a gallium oxide layer or provided with the gallium oxide layer with a thickness of 1 nanometer or smaller.