Memory effect and retention property of Ge nanocrystal embedded Hf-aluminate high-k gate dielectric
The memory effect and retention characteristics of a Ge nanocrystal (NC) floating gate memory structure consisting of Hf-aluminate (HfA1O) tunnelling and control oxides have been investigated by means of high-frequency capacitance-voltage (C-V) and capacitance-time (C-t) measurements. The trilayer s...
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Published in | Nanotechnology Vol. 17; no. 5; pp. 1202 - 1206 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
IOP Publishing
14.03.2006
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Online Access | Get full text |
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Summary: | The memory effect and retention characteristics of a Ge nanocrystal (NC) floating gate memory structure consisting of Hf-aluminate (HfA1O) tunnelling and control oxides have been investigated by means of high-frequency capacitance-voltage (C-V) and capacitance-time (C-t) measurements. The trilayer structure (HfAlO/Ge-NC/HfAlO) on Si was fabricated by pulsed-laser deposition at a relatively low temperature. A high-resolution transmission electron microscopy study revealed that the Ge nanocrystals are about 5 nm in diameter and are well distributed within the amorphous HfAlO matrix. The memory effect was revealed by the counter-clockwise hysteresis loop in the C-V curves and a high storage charge density of about 1 x 1013 CM -2 and a large flat-band voltage shift of 3.6 V have been achieved. An 8% decay in capacitance after 104 s in the C-t measurement suggests a promising retention property of Ge NC charge storage. The effects of size/density of the Ge NC, the tunnelling and control oxide layer thicknesses and their growth oxygen partial pressure to the charge storage and charge retention characteristics have been studied. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0957-4484 1361-6528 |
DOI: | 10.1088/0957-4484/17/5/006 |