Share Email Print
cover

Proceedings Paper

Ge nanocrystals embedded in Hf-aluminate high-k gate dielectric for floating gate memory application
Author(s): Pui Fai Lee; Wei Li Liu; Zhi Tang Song; Ji Yan Dai
Format Member Price Non-Member Price
PDF $17.00 $21.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Recently, many efforts have been made to improve the device performance of nanocrystal memory by replacing the SiO2 with various high dielectric constant (high-k) materials, especially embedded with Ge nanocrystals. This paper demonstrates the floating gate memory effect by embedding nanometer-sized Ge nanocrystals in hafnium aluminate (HfAlO) high-k gate dielectric. A 5 nm-thick amorphous thin film of HfAlO was first deposited on (100) p-Si substrates as a tunneling gate oxide layer by laser molecular beam epitaxy deposition using a HfO2 and Al2O3 composite target. Well-defined (~10 nm in diameter) nanometer-sized Ge dots were subsequently deposited on this thin tunneling gate oxide followed by a 30 nm-thick top control gate oxide of HfAlO. Transmission electron microscopy has been carried out for a detailed study of structural properties of the Ge nanocrystals embedded in the HfAlO films, and their relationships to electrical properties. Electrical properties have been characterized by means of high-frequency capacitance-voltage (C-V) and current-voltage (I-V) measurements on the metal-oxide-semiconductor capacitors. A counter-clockwise hysteresis C-V loop has been obtained and a threshold voltage shift of 1.0 V has been achieved indicating stored electrons (up to a density of 2x1012 cm-2) in the Ge-nanodots floating gate and thus the memory effect. Time-dependent I-V measurement also showed low leakage current of floating gate system. These results suggest that the Ge nanocrystals embedded in HfAlO are promising for floating gate memory device application.

Paper Details

Date Published: 23 February 2005
PDF: 6 pages
Proc. SPIE 5650, Micro- and Nanotechnology: Materials, Processes, Packaging, and Systems II, (23 February 2005); doi: 10.1117/12.582062
Show Author Affiliations
Pui Fai Lee, Hong Kong Polytechnic Univ. (Hong Kong China)
Wei Li Liu, Hong Kong Polytechnic Univ. (Hong Kong China)
Shanghai Institute of Microsystem and Information Technology, CAS (China)
Zhi Tang Song, Shanghai Institute of Microsystem and Information Technology, CAS (China)
Ji Yan Dai, Hong Kong Polytechnic Univ. (Hong Kong China)


Published in SPIE Proceedings Vol. 5650:
Micro- and Nanotechnology: Materials, Processes, Packaging, and Systems II
Jung-Chih Chiao; David N. Jamieson; Lorenzo Faraone; Andrew S. Dzurak, Editor(s)

© SPIE. Terms of Use
Back to Top