Electron-Trap and Hole-Trap Distributions in Metal/Oxide/Nitride/Oxide/Silicon Structures

• Published in: IEEE transactions on electron devices Vol. 60; no. 2; pp. 863 - 869
• Main Authors: Ishida, T., Mine, T., Hisamoto, D., Shimamoto, Y., Yamada, R.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.02.2013; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Avalanche injection; Capacitors; Compound structure devices; Design. Technologies. Operation analysis. Testing; Dielectric, amorphous and glass solid devices; electron trap; Electron traps; Electronics; Exact sciences and technology; Flash memory; hbox{Si}_{3}\hbox{N}_{4}; hole trap; Integrated circuits; Integrated circuits by function (including memories and processors); metal/oxide/nitride/oxide/silicon (MONOS); MONOS devices; Niobium; nitride; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silicon; SONOS; vertical trap distribution; Interfacial layer; SONOS; nitride; electron trap; Silicon nitride; SONOS structure; Avalanche injection; Coulomb interaction; N; hole trap; Electron traps; Charge carrier trapping; metal/oxide/nitride/oxide/silicon (MONOS); Non volatile memory; Flash memory; Si; Integrated circuit; vertical trap distribution; Electron emission; MONOS structure; Capacitor; Activation energy; Hole traps; Voltage capacity curve
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2012.2235145

Distributions of both electron traps and hole traps in metal/oxide/nitride/oxide/silicon (MONOS) structures were studied. These trap distributions were analyzed by using a combination of an avalanche-injection method and capacitance-voltage measurement. The thicknesses of the nitride layers in the MONOS capacitors were varied. It was found that electron traps are mainly located at both the top and bottom oxide/nitride interfaces, whereas hole traps are located at the interfaces as well as in the nitride bulk. This analysis clarified that electron-trap capability decreases anomalously in the range of nitride thickness of less than 4 nm. Moreover, the effective activation energy of electron emission also decreases at nitride thickness less than around 5 nm. These decreases are considered to be accounted for by detrapping due to the Coulomb repulsion between electrons at both interfaces and electron trapping in the interfacial transition layers.