Novel multi-bit SONOS type flash memory using a high-k charge trapping layer

Authors :: H. Minakata
M. Kobayashi
Yasuyuki Tamura
H. Tanaka
T. Sugizaki
Toshiro Nakanishi
M. Ishidao
Y. Sugiyama
M. Yamaguchi
Source :: 2003 Symposium on VLSI Technology. Digest of Technical Papers (IEEE Cat. No.03CH37407).
Publication Year :: 2004
Publisher :: Japan Soc. Applied Phys, 2004.
Abstract: We demonstrated SONOS flash memory with a SiO/sub 2//High-k/SiO/sub 2/ structure based on a 2-bit/cell scheme. We evaluated three kinds of high-k dielectric films which were Si/sub 3/N/sub 4/, Al/sub 2/O/sub 3/ and HfO/sub 2/. Among these films, Al/sub 2/O/sub 3/ showed superior retention characteristics. The charge loss amount of Al/sub 2/O/sub 3/ at 150/spl deg/C is almost the same as that of Si/sub 3/N/sub 4/ at 25/spl deg/C. HfO/sub 2/ showed poor retention characteristics. In addition, we have found that each film has a different charge loss mechanism. We speculate that Si/sub 3/N/sub 4/ causes vertical charge migration, Al/sub 2/O/sub 3/ causes scarcely any leakage, and HfO/sub 2/ causes lateral charge migration. As a consequence, Al/sub 2/O/sub 3/ is very suitable for a charge trapping layer in multi-bit SONOS memory.

Subjects :: Materials science
Electronic engineering
Analytical chemistry
Charge loss
Structure based
Dielectric loss
Dielectric
Trapping
Dielectric thin films
Flash memory
Leakage (electronics)

Database :: OpenAIRE
Journal :: 2003 Symposium on VLSI Technology. Digest of Technical Papers (IEEE Cat. No.03CH37407)
Accession number :: edsair.doi...........52d109cbf54f7d5836150189ec200fe3
Full Text :: https://doi.org/10.1109/vlsit.2003.1221069