利用雷射變頻退火改善具氧化鉿鑭閘介電層金氧半電容之電與可靠度特性研究

本研究利用雷射變頻退火改善具氧化鉿鑭閘介電質金氧半電容之電與可靠度特性研究，使用高真空金屬薄膜濺鍍機，以射頻沉積氧化鉿鑭閘介電層，搭配Ta與Al為電極，研究快速熱退火(RTA)、雷射變頻退火(Laser annealing)的退火方式對金氧半電容特性的影響。實驗結果顯示，以高真空金屬薄膜濺鍍機沉積高介電係數介電層HfLaO厚度為30Å，經過850℃快速熱退火(RTA)處理後，等效氧化層厚度(EOT)約為1.6 nm，介面陷阱密度(Dit)為1.62 x1010 cm-2 eV-1。另一方面，使用相同方式沉積厚度3 nm的高介電係數介電層HfLaO，改用雷射退火熱處理。雷射退火使用1024nm之Nd:YAG雷射，雕刻速度設定 100公釐/秒、輸出功率為11.2 W(70%)、頻率設定20 ~40 kHz。實驗結果顯示，經由雷射退火的HfLaO其EOT為1.16 nm，其界面陷阱密度為2.94 x1010cm-2eV-1，藉由改變雷射的輸出功率、雕刻速度、頻率，可增加具HfLaO閘介電層金氧半電容的電特性。

關鍵字

濺鍍機；氧化鉿；雷射退火；高介電係數材料金氧半電容

並列摘要

In this thesis, the improved electrical and reliability characteristics of metal-oxide- semiconductor (MOS) capacitors with HfLaO dielectrics using laser annealing with were who’s demonstrated frequence. The HfLaO dielectric was formed by the RF sputter. The Ta and Al films were used for the electrode of MOS capacitors. The comparison of HfLaO-gated MOS capacitors with the rapid-thermal annealing (RTA) and laser annealing (LA) were achieved. The results suggest that the HfLaO-gated MOS capacitor with EOT of 1.6 nm and interface trap density of 1.62 x 1010 cm-2eV-1 was explored. On the other hand, the HfLaO-gated MOS capacitors with LA were also addressed. The 1024 nm in wavelength of the Nd:YAG laser was used to demonstrate the electrical and reliability properties of MOS capacitor. The conditions of laser include laser power, speed, and frequency. The results indicate that the HfLaO-gated MOS capacitor with EOT of 1.16 nm was demonstrated by using LA under speed of 100 mm/s, power of 70%, and frequency of 20 ~ 40 kHz. By tuning suitably laser condition, high quality HfLaO dielectric can be obtained.

並列關鍵字

sputter ； HfLaO ； laser annealing ； High-dielectric-constant materials ； metal- oxide-semiconductor (MOS)

參考文獻

[1] X. P. Wang, H. Y. Yu, M.-F. Li, C. X. Zhu, S. Biesemans, A. Chin, Y. Y. Sun, Y. P. Feng, A. Lim, Y. C. Yeo, W. Y. Loh, G. Q. Lo, D. L. Kwong, “Wide Vfb and Vth Tunability for Metal-Gated MOS Devices With HfLaO Gate Dielectrics,” IEEE Electron Device Lett., vol. 28, No. 4, pp. 258-260, Apr. 2007.

[2] S. Z. Chang, H. Y. Yu, C. Adelmann, A. Delabie, X. P. Wang, S. Van Elshocht, A. Akheyar, L. Nyns, J. Swerts, M. Aoulaiche, C. Kerner, P. Absil, T. Y. Hoffmann, and S. Biesemans, “Electrical Properties of Low-VT Metal-Gated n-MOSFETs Using La2O3/SiOx as Interfacial Layer Between HfLaO High-κ Dielectrics and Si Channel” IEEE Electron Device Lett., vol. 29, No. 5, pp. 430-433, May. 2008.

[3] B. Lee, S. R. Novak, D. J. Lichtenwalner, X. Yang, V. Misra, “Investigation of the Origin of VT/VFB Modulation by La2O3 Capping Layer Approaches for NMOS Application: Role of La Diffusion, Effect of Host High-k Layer, and Interface Properties” IEEE Trans. Electron Devices, vol. 58, No. 9, pp. 3106-3115, Sep. 2011.

[4] K. Kirah, “Modelling of stress-induced leakage current in short-channel n-MOSFETs,” IET Electronics Letters, vol. 48, No. 7, pp. 404-405, Mar. 2012.

[5] A. Kerber, E. A. Cartier, “Reliability Challenges for CMOS Technology Qualifications With Hafnium Oxide/Titanium Nitride Gate Stacks,” IEEE Trans. Device and Materials Reliabilitys, vol. 9, No. 2, pp. 147-162, Jun. 2009.

國際替代計量

利用雷射變頻退火改善具氧化鉿鑭閘介電層金氧半電容之電與可靠度特性研究

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