Title :
Abnormal VTH/VFB shift caused by as-grown mobile charges in Al2O3 and its impacts on Flash memory cell operations
Author :
Tang, B.J. ; Zhang, W.D. ; Zhang, J.F. ; Van den Bosch, G. ; Govoreanu, B. ; Van Houdt, J.
Author_Institution :
Sch. of Eng., Liverpool John Moores Univ., Liverpool, UK
Abstract :
High-k stacks will be used in Flash memory cells for technology beyond sub-30 nm generations. Abnormal window shift during memory operations has been observed and was attributed to trapping/detrapping of electrons or dielectric relaxation in the high-k layer. In this work, the cause of abnormal VTH/VFB shift at low operating electric fields is investigated. For the first time, extensive experimental evidences show that this shift is caused by as-grown mobile charges in Al2O3 layers. Its impacts on program/erase windows and read/pass disturbance in Flash memory cells are evaluated.
Keywords :
alumina; electric fields; electron traps; flash memories; high-k dielectric thin films; nanoelectronics; Al2O3; abnormal VTH-VFB shift; abnormal window shift; as-grown mobile charges; dielectric relaxation; electric fields; electron detrapping; electron trapping; flash memory cell operation; high-k stacks; memory operations; program-erase windows; read-pass disturbance; Aluminum oxide; Capacitance-voltage characteristics; Charge carrier processes; Electric fields; Logic gates; Mobile communication; Pulse measurements;
Conference_Titel :
Electron Devices Meeting (IEDM), 2011 IEEE International
Conference_Location :
Washington, DC
Print_ISBN :
978-1-4577-0506-9
Electronic_ISBN :
0163-1918
DOI :
10.1109/IEDM.2011.6131523
