Anderson’s negative- U chemistry in amorphous silicon nitride: A complex system approach

Science Advances, vol. 11, pp. eadx9540

Abstract

P. W. Anderson introduced a negative- U (i.e., attractive electron-electron interaction) to describe the scarcity of singly occupied spin states in amorphous materials. To uncover the underlying chemistry behind this phenomenon, we combined structural sampling with quantum-chemical analysis of amorphous silicon nitride (a-SiN x ) based on DFT. Our analysis demonstrates that coordination defects act as charge traps, with a density on the order of 10 21 per cubic centimeter. These defects render singly occupied electronic states energetically less favorable than paired or fully emptied states, primarily due to electron donor-acceptor interactions. Furthermore, excess charge trapping occurs through chemical bond reorganization, which disrupts the balance of existing electron and hole traps. In addition, we found that in Si-rich a-SiN x , various Si─Si bonding networks exhibit power-law–like size distribution, where larger networks are associated with deeper trap levels. These findings explain why a-SiN x has been used as a charge storage layer in the charge trap flash memory.

Authors 8

1. Woon Ih Choi corresponding

   Samsung (South Korea) · Samsung Electronics (South Korea)

   Affiliation as printed

   Computational Science and Engineering Team, Semiconductor R&D Center, Samsung Electronics, Gyeonggi-do 17113, South Korea

2. Bokyeom Kim

   Samsung (South Korea) · Samsung Electronics (South Korea)

   Affiliation as printed

   Computational Science and Engineering Team, Semiconductor R&D Center, Samsung Electronics, Gyeonggi-do 17113, South Korea

3. Uihui Kwon

   Samsung (South Korea) · Samsung Electronics (South Korea)

   Affiliation as printed

   Computational Science and Engineering Team, Semiconductor R&D Center, Samsung Electronics, Gyeonggi-do 17113, South Korea

4. Yong-Hee Cho

   Samsung (South Korea) · Samsung Electronics (South Korea)

   Affiliation as printed

   Computational Science and Engineering Team, Semiconductor R&D Center, Samsung Electronics, Gyeonggi-do 17113, South Korea

5. Won‐Joon Son

   Samsung (South Korea) · Samsung Electronics (South Korea)

   Affiliation as printed

   Computational Science and Engineering Team, Semiconductor R&D Center, Samsung Electronics, Gyeonggi-do 17113, South Korea

6. Hawoong Jeong

   Korea Advanced Institute of Science and Technology

   Affiliation as printed

   Department of Physics and Center for Complex Systems, Korea Advanced Institute of Science and Technology, Daejeon 34141, South Korea

7. Richard Dronskowski corresponding Aachen Chair of Solid-State and Quantum Chemistry Institute of Inorganic Chemistry

   RWTH Aachen University

   Affiliation as printed

   Chair of Solid-State and Quantum Chemistry, Institute of Inorganic Chemistry, RWTH Aachen University, 52056 Aachen, Germany

8. Dae Sin Kim

   Samsung (South Korea) · Samsung Electronics (South Korea)

   Affiliation as printed

   Computational Science and Engineering Team, Semiconductor R&D Center, Samsung Electronics, Gyeonggi-do 17113, South Korea