Origin of the two-dimensional hole gas and criteria for its existence in the III-nitride heterostructures

• Main Authors: Lingaparthi, R., Dharmarasu, Nethaji, Radhakrishnan, K.
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2023
• Subjects: Engineering::Electrical and electronic engineering; Acceptor State; Distribution Models
• Online Access: https://hdl.handle.net/10356/169147
• Institution: Nanyang Technological University

The existence of the two-dimensional electron gas (2DEG) and two-dimensional hole gas (2DHG) in the same III-nitride heterostructure is advantageous for the development of complementary nitride electronics. However, it is still unclear whether the buried-2DHG and the top 2DEG can coexist in the same III-nitride heterostructure. This study has addressed this long-standing question. Using charge distribution model, a systematic analysis is done and proposed surface acceptor states as the origin of the two-dimensional hole gas (2DHG). Using this centralized analysis, factors affecting the formation of both surface and buried-2DHG in the nitride heterostructures are presented. Furthermore, it is proved that the buried-2DHG is absent in III-nitride heterostructures, particularly under the 2DEG. In the absence of buried-2DHG at the GaN/AlXGa1-XN interface, a hole trap is observed, which not only balances the charge distribution but also reduces the electric field in the GaN channel layer.