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Silicon nanoparticle charge trapping memory cell
Author(s) -
ElAtab Nazek,
Ozcan Ayse,
Alkis Sabri,
Okyay Ali K.,
Nayfeh Ammar
Publication year - 2014
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201409157
Subject(s) - quantum tunnelling , electric field , atomic layer deposition , nanoparticle , materials science , silicon , trapping , threshold voltage , nanotechnology , optoelectronics , analytical chemistry (journal) , condensed matter physics , layer (electronics) , voltage , chemistry , electrical engineering , physics , transistor , ecology , quantum mechanics , biology , engineering , chromatography
A charge trapping memory with 2 nm silicon nanoparticles (Si NPs) is demonstrated. A zinc oxide (ZnO) active layer is deposited by atomic layer deposition (ALD), preceded by Al 2 O 3 which acts as the gate, blocking and tunneling oxide. Spin coating technique is used to deposit Si NPs across the sample between Al 2 O 3 steps. The Si nanoparticle memory exhibits a threshold voltage ( V t ) shift of 2.9 V at a negative programming voltage of –10 V indicating that holes are emitted from channel to charge trapping layer. The negligible measured V t shift without the nanoparticles and the good re‐ tention of charges (>10 years) with Si NPs confirm that the Si NPs act as deep energy states within the bandgap of the Al 2 O 3 layer. In order to determine the mechanism for hole emission, we study the effect of the electric field across the tunnel oxide on the magnitude and trend of the V t shift. The V t shift is only achieved at electric fields above 1 MV/cm. This high field indicates that tunneling is the main mechanism. More specifically, phonon‐assisted tunneling (PAT) dominates at electric fields between 1.2 MV/cm < E < 2.1 MV/cm, while Fowler–Nordheim tunneling leads at higher fields ( E > 2.1 MV/cm). (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)