GaN HEMT Nitrogen Surface Contacts for Lower Ohmic Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current high electron mobility transistors based on gallium nitride suffer from high ohmic contact resistance, limiting their performance in high-frequency and power applications.
Innovation Solution
A high electron mobility transistor structure is developed with a two-dimensional electron gas layer formed through polarization at the heterojunction interface between the channel and barrier layers, utilizing a nitrogen surface to reduce ohmic contact resistance, and incorporating a diamond substrate for improved heat dissipation, along with specific layer configurations such as silicon-doped aluminum gallium nitride and iron/carbon-doped gallium nitride layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional high electron mobility transistor structure based on gallium nitride is used, then the transistor can operate in power electronics and radio frequency applications, but the ohmic contact resistance is high which limits performance
Solution Approach 1:
The patent applies local quality by creating a nitrogen-terminated surface specifically at the contact region between the metal electrode and the GaN channel layer. This localized surface termination modification reduces the ohmic contact resistance at the contact interface without changing the bulk properties of the transistor, thereby improving performance in high-frequency and power applications while maintaining the overall device structure.
Solution Approach 2:
The patent changes the surface termination parameter of the GaN channel layer from gallium-terminated to nitrogen-terminated. This parameter change fundamentally alters the electronic properties at the surface, creating a lower resistance contact interface. The nitrogen-terminated surface provides better ohmic contact characteristics, directly addressing the high ohmic contact resistance issue in conventional HEMTs.
2Ease of manufacture
If gallium surface is used in high electron mobility transistor, then the transistor structure can be formed, but the ohmic contact resistance remains high
Solution Approach 1:
The patent inverts the conventional approach by terminating the GaN surface with nitrogen instead of gallium. Conventional HEMTs use gallium-terminated surfaces, but this patent reverses the termination to nitrogen, which fundamentally changes the surface electronic properties and enables lower ohmic contact resistance while maintaining ease of manufacture through standard epitaxial growth processes.
3Productivity
If conventional substrate materials are used, then the transistor can be manufactured, but heat dissipation performance is insufficient for high power applications
Solution Approach 1:
The patent employs composite material strategy by integrating a diamond substrate with the GaN-based HEMT structure. Diamond provides exceptional thermal conductivity for effective heat dissipation, while the GaN layer maintains the high electron mobility and radio frequency performance. This composite structure enables high power density applications by solving the heat management issue without compromising electrical performance.
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
The structure achieves lower ohmic contact resistance and enhanced heat dissipation, enabling better performance in high-frequency and power scenarios, with improved crystal quality and increased power density.
Implementation Method 1
The two-dimensional electron gas layer is generated through a polarization effect at a junction interface between the channel layer and the barrier layer
Implementation Method 2
the diamond material has higher thermal conductivity, heat dissipation performance of the component can be effectively improved
Data Source
AI summary
A high electron mobility transistor, a radio frequency transistor, and a preparation method for a high electron mobility transistor, and relates to the field of microelectronics technologies, to resolve a technical problem of poor performance of a high electron mobility transistor with a nitrogen surface. The high electron mobility transistor includes a channel layer, a barrier layer, and a substrate layer. A surface that is of the channel layer and that is in contact with the barrier layer has a two-dimensional electron gas layer. The high electron mobility transistor further includes a source and a drain. The source and the drain are located on the channel layer, and the source and the drain are in ohmic contact with the channel layer. The high electron mobility transistor can implement a low ohmic contact resistance and can be better used in a high frequency and power scenario.