Group III Nitride Device Charge Injection Barrier
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Group III nitride-based devices for power electronics face performance and reliability issues due to carrier injection from ohmic contacts into the passivation layer, leading to leakage currents and reduced device reliability.
Innovation Solution
A charge injection barrier is introduced between the ohmic contact structure and the passivation layer, preventing surface contact and leakage currents by extending continuously on the side walls and upper surface of the passivation layer, using materials like oxides, nitrides, or metal nitrides with higher work functions than the ohmic contact.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ohmic contact structure is directly connected to passivation layer, then manufacturing is simpler, but leakage current increases and device reliability deteriorates
Solution Approach 1:
A charge injection barrier layer is introduced as an intermediary between the ohmic contact structure and the passivation layer. This barrier layer prevents direct contact and carrier injection from the ohmic contact into the passivation layer, thereby eliminating leakage current paths while maintaining structural integrity and device reliability.
Solution Approach 2:
The contact structure is segmented into multiple distinct layers: the ohmic contact structure, the charge injection barrier layer, and the passivation layer. This segmentation creates functional separation where each layer performs its specific role, preventing harmful interactions while maintaining overall system functionality.
2Reliability
If charge injection barrier extends continuously on side walls and upper surface, then leakage current is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The charge injection barrier is extended from a simple planar layer into the third dimension by forming it on the side walls of the opening in addition to the upper surface. This three-dimensional configuration ensures complete coverage and prevents leakage current along side wall paths, providing comprehensive protection against leakage while maintaining manufacturability through standard deposition techniques.
3Object-generated harmful factors
If charge injection barrier is added between ohmic contact and passivation layer, then leakage current is prevented, but device complexity and manufacturing steps increase
Solution Approach 1:
The charge injection barrier serves as a mediating layer that blocks harmful carrier injection from the ohmic contact into the passivation layer without interfering with the primary electrical function. This intermediary approach eliminates leakage current while adding minimal structural complexity.
Solution Approach 2:
The barrier layer utilizes material parameter differences, specifically having a higher work function than the ohmic contact materials (such as titanium, aluminum, or copper), to create an energy barrier that prevents carrier injection. This parameter-based solution provides effective leakage prevention through material selection rather than complex structural design.
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 solution enhances the performance and reliability of Group III nitride devices by reducing carrier injection and leakage currents, improving contact resistance and overall device stability.
Implementation Method 1
A charge injection barrier is introduced between the ohmic contact structure and the passivation layer, preventing surface contact and leakage currents
Implementation Method 2
A charge injection barrier is introduced between the ohmic contact structure and the passivation layer, preventing surface contact and leakage currents by extending continuously on the side walls and upper surface of the passivation layer
Data Source
Figure 1A
Figure 1B
Figure 2~3
AI summary
In an embodiment, a Group III nitride device (10, 10', 40, 50, 60, 70, 80), comprises a Group III nitride layer (11), a passivation layer(12) arranged on the Group III nitride layer (11) and comprising a first opening (13), a first ohmic contact structure (14, 14') arranged in the first opening (13) and forming an ohmic contact to the Group III nitride layer (11) and a charge injection barrier (15, 45, 55, 65, 85). The charge injection barrier (15, 45, 55, 65, 85) is arranged between the first ohmic contact structure (14, 14') and the passivation layer (12). The charge injection barrier (15, 45, 55, 65, 85) forms no ohmic contact to the Group III nitride layer (11).