標題: Characteristics of atomic-layer-deposited Al(2)O(3) high-k dielectric films grown on Ge substrates
作者: Cheng, Chao-Ching
Chien, Chao-Hsin
Luo, Guang-Li
Liu, Jun-Cheng
Kei, Chi-Chung
Liu, Da-Ren
Hsiao, Chien-Nan
Yang, Chun-Hui
Changa, Chun-Yen
電子工程學系及電子研究所
Department of Electronics Engineering and Institute of Electronics
公開日期: 2008
摘要: This paper describes the structural and electrical properties of Al(2)O(3) thin films grown through atomic layer deposition onto Ge substrates over a wide deposition temperature range (50-300 degrees C). From grazing-incidence X-ray reflectivity and X-ray photoelectron spectroscopy, we found that increasing the deposition temperature improved the Al(2)O(3) film density and its dielectric stoichiometry; nevertheless, dielectric intermixing between main Al(2)O(3) and interfacial GeO(2) appeared at temperatures above 200 degrees C, along with degradation of the GeO(2)/Ge interface. Accordingly, a relatively large gate leakage current (J(g)) and a high density of interfacial states D(it) (> 10(13) cm(-2) eV(-1)) were observed as a result of deterioration of the entire Al(2)O(3)/Ge structure at higher deposition temperatures. In addition, although subsequent high-temperature processing at 600 degrees C in a N(2) ambient could relieve the oxygen-excessive behavior further, i.e., to provide a more stoichiometric film, the accompanying GeO(x) volatilization close to the dielectric interface caused greater damage to the electrical performance. Only forming gas annealing (H(2)/N(2), 1:10) at low temperature (300 degrees C) improved the capacitance-voltage characteristics of the Pt/Al(2)O(3)/Ge structure, in terms of providing a lower value of D(it) (ca. 6 x 10(11) cm(-2) eV(-1)), a lower value of J(g), and a reduced hysteresis width.
URI: http://hdl.handle.net/11536/9892
http://dx.doi.org/10.1149/1.2965495
ISSN: 0013-4651
DOI: 10.1149/1.2965495
期刊: JOURNAL OF THE ELECTROCHEMICAL SOCIETY
Volume: 155
Issue: 10
起始頁: G203
結束頁: G208
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