Complementary GaN ICs via 2DEG and 2DHG Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gallium nitride (GaN) high electron mobility transistors (HEMTs) face challenges in design due to the complexity of forming a heterojunction channel, which affects their performance in high power and high speed switching applications compared to conventional silicon-based technologies.
Innovation Solution
A complementary GaN integrated circuit (IC) is developed with a first GaN layer, a second n-type donor supply layer, and a third p-type doped layer, forming a two-dimensional electron gas (2DEG) and hole gas (2DHG) at the contact regions, enabling the creation of monolithic transistors of different conductivity types, enhancing mechanical stability and facilitating the fabrication of N-channel and P-channel transistors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a heterojunction channel is formed in GaN HEMT, then high electron mobility and high power capability are achieved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent segments the GaN layer into multiple distinct layers with different doping types (n-type GaN layer, p-type GaN layer) and different thicknesses. This segmentation allows each layer to perform specific functions while simplifying the overall device structure and manufacturing process compared to traditional heterojunction designs.
Solution Approach 2:
The patent applies local quality by creating regions with different electrical properties within the GaN structure. Specifically, it forms n-type and p-type regions with different doping concentrations and thicknesses, allowing localized control of carrier concentration and electrical characteristics to achieve high power capability while managing device complexity.
2Ease of operation
If conventional silicon-based technologies are used, then design ease is improved, but high power and high speed switching performance is reduced compared to GaN
Solution Approach 1:
The patent creates a universal GaN-based platform that can support both n-channel and p-channel transistors using the same fundamental layer structure. This multi-functionality allows the device to achieve high power and high speed switching performance while maintaining design flexibility and ease of operation through standardized fabrication processes.
Solution Approach 2:
The patent achieves high power performance by carefully controlling and varying key parameters such as layer thickness (first thickness for n-type region, second thickness for p-type region), doping concentrations, and bandgap differences. These parameter changes enable optimization of electron and hole mobility while maintaining design simplicity.
3Stability of the object's composition
If monolithic transistors of different conductivity types are created, then device integration and mechanical stability are improved, but fabrication complexity increases
Solution Approach 1:
The patent merges n-type and p-type transistor fabrication into a single monolithic GaN structure. By combining both conductivity types in one continuous GaN layer system with coordinated layer thicknesses and doping profiles, it achieves improved mechanical stability and simplifies the overall device architecture while managing fabrication complexity through integrated processing.
Solution Approach 2:
The patent utilizes composite material structures within the GaN system, combining n-type and p-type doped regions with different thicknesses and electrical properties. This composite approach enables monolithic integration of different conductivity types while maintaining mechanical stability through the unified GaN crystal structure.
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 solution allows for the creation of stable and efficient GaN ICs with monolithic N-channel and P-channel transistors, improving mechanical stability and enabling high power, high speed switching applications by leveraging the 2DEG and 2DHG formations, thus addressing the design challenges of GaN HEMTs.
Implementation Method 1
a heterojunction, rather than a doped region, provides the conductive channel of the transistor. In such a HEMT, the heterojunction (or the channel) exists in a contact region between two layers of semiconductor materials having different bandgaps
Implementation Method 2
a two-dimensional electron gas (2DEG) may be present within a contact region between a GaN substrate and a barrier layer (e.g., an aluminum GaN (AIGaN) layer). The 2DEG essentially is a concentration of electrons at the heterojunction that are free to move in two dimensions
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
An embodiment of a complementary GaN integrated circuit (110, 1110) includes a GaN layer (130, 230, 730) with a first bandgap. A second layer (140, 440, 1040) with a second bandgap is formed on the GaN layer, resulting in a 2DEG (122, 222, 322, 722) in a contact region between the GaN layer and the second layer. The second layer has a relatively thin portion and a relatively thick portion. A third layer (150, 550, 1050) is formed over the relatively thick portion of the second layer. The third layer has a third bandgap that is different from the second bandgap, resulting in a 2DHG (112, 512, 812, 1012) in a contact region between the second layer and the third layer. A transistor (110, 610, 1110) of a first conductivity type includes the 2DHG, the relatively thick portion of the second layer, and the third layer, and a transistor (120, 620, 1120) of a second conductivity type includes the 2DEG and the relatively thin portion of the second layer.