Nitride semiconductor materials are the core basic materials of semiconductor lighting, full-color display, power electronics and other devices, in which they have achieved large-scale industrial applications today, nitride material growth interface research still has important scientific significance, over time.
Recently, the Lighting R&D Center of the Institute of Semiconductors of the Chinese Academy of Sciences (hereinafter referred to as the “Institute of Semiconductors”) and the State Key Laboratory of Semiconductor Superlattices of the Institute of Semiconductors of the Chinese Academy of Sciences, the University of North Carolina, and the Center for Quantum Materials Science of Peking University have made new progress in the research of the growth process of the growth interface of nitride materials, with the title of “MoCVD Method for the Spontaneous Polarity Reversal Atomic Mechanism of AlN Materials Grown on Sapphire Substrates”, published in Small Magazine.
“Interface is device”, the interface is the basis of device design, but also the core of material growth control. In the 1980s, Japanese scientists first realized the epitaxial of nitride materials, but for more than 30 years, there are still a lot of academic controversies at the growth interface, and the traditional research method of “speculating on the interface from the surface” often causes wrong cognition, and this research provides direct evidence for resolving academic disputes.
Spontaneous polarization flipping of the nitride growth interface Picture from the paper
The research team found that the lattice arrangement of nitride materials grown on sapphires through MOCVD is not directly inherited from the nitride/sapphire interface, but undergoes a spontaneous polarity reversal during growth. They also used first-principles calculations to reveal the most stable atomic configuration and interfacial growth front end of nitriding on the surface of sapphire substrates. After leaving the heterogeneous interface, the nitride lattice will spontaneously achieve a reversal from N polarity to metal polarity through polarity flipping grain boundaries (IDBs).
According to reports, the research team answered the scientific question of “heterojunction configuration and atomic level deposition process” of nitride MOCVD, elucidated the polarity selection and evolution mechanism of nitride lattice, and confirmed that in addition to lattice mismatch and thermal mismatch, naturally occurring IDBs are another important cause of high misdense of nitrides.
Liu Zhiqiang, a researcher at the Institute of Semiconductors, is the first author of the paper, and he and Gao Peng, researcher of Peking University, Yang Shengyuan, associate researcher of the Institute of Semiconductors, and Professor Daniel Zhang of The University of North Carolina are co-corresponding authors. (Source: China Science Daily Hu Minqi)
Related paper information:https://doi.org/10.1002/smll.202200057