The Effect of higher-κ Lanthanum Titanate capping on HfO2 gate oxide via Atomic Layer Deposition

以原子層化學氣相沈積鍍製高介電鈦酸鑭薄膜與覆蓋於二氧化鉿閘極氧化層之影響

喻詩維(Shih-Wei Yu)

指導教授 ： 吳泰伯

國立清華大學/工學院/材料科學工程學系/碩士(2010年)

https://doi.org/10.6843/NTHU.2010.00300

摘要

Abstract
High-κ materials have attracted great attention for their applications in nano-scaled CMOS structures and memory. However, with the trend of scaling down in International Technology Roadmap for Semiconductors (ITRS), seeking for higher-κ dielectric oxides will be the key to meet the requirement for 22 nm and 15 nm node of CMOS technology.
Lanthanum titanate (LTO) had been reported to have high dielectric constant and high crystallization temperature, which is taking the merit of TiO2 in high permittivity and La2O3 in thermal stability. Thus the higher-κ dielectric LTO is expected to have its potential in future high-κ dielectric.
The LTO films is deposited on HfO2 in stacks structure via atomic layer deposition (ALD) technique in this study. The precursor systems used for deposition of lanthanum titanates were Tetrakis(dimethylamino) Titanium (TDMAT) + water and tris(N-N’-diisopropylformamidinato) Lanthanum (La(iPr2-FMD)3) + oxygen plasma. The electrical characteristics were measured in C-V and I-V relations, and the microstructure of thin films was inspected by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray reflectivity (XRR) and X-ray photoelectron spectroscopy (XPS).
The LTO film is observed to diffuse in HfO2 through heat treatment, and yield in a new high-κ material which exhibits better properties than traditional HfO2 thin film and displays higher permittivity of 34.5 and lower equivalent oxide thickness (EOT) of 0.69 nm with a low leakage current of 10-2 A/cm2.

關鍵字

High-k ； 閘極氧化層 ； 二氧化鉿 ； 三氧化二鑭 ； 鈦酸鑭 ； 等效界面層厚度 ； 介電常數

並列摘要

無資料

並列關鍵字

High-k ； Gate Oxide ； Hafnium oxide ； Lanthanum oxide ； Lanthanum Titanate ； Effective oxide thickness ； Dielectric

參考文獻

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