高純度Hf靶材與HfO2薄膜特性研究

Characteristics of pure Hf target and HfO2 thin films

陳弘軒(Hung-Shiuan Chen)

指導教授 ： 王玉瑞 ； 王錫福

國立臺北科技大學/工程學院/資源工程研究所/碩士(2011年)

摘要

隨著IC製程的演進，元件尺寸越做越小，而閘極氧化層二氧化矽(SiO2)也越來越薄，使得直接穿隧漏電流(Direct Tunneling)的增加，造成元件漏電流與功率損耗，所以使用高介電常數材料(High Dielectric Constant)來取代SiO2，一般稱為High-k 材料。在相同電容下，High-k介電層的厚度是SiO2之數倍，能夠有效降低直接穿隧漏電流，且許多研究指出HfO2為最有希望取代SiO2作為閘極介電層之材料。本實驗使用DC磁控濺鍍方式，以Hf金屬靶材經反應性濺鍍形成HfO2薄膜。實驗參數包括氣體比(Ar:O2)、基板溫度、退火溫度、退火氣氛、退火時間，並以不同Sc3+摻雜量與自製型Hf靶材製備HfO2薄膜。結果顯示：提高氣體比(Ar:O2)為1:10之介電常數高達35.4；氣體比(Ar:O2)=10:1及基板溫度300℃、氣體比(Ar:O2)=1:1並以Ar 600℃/O2 500℃退火30分鐘與摻雜Sc3+為6.95 atom%之參數，均可使漏電流降至10-9A/cm2。

關鍵字

濺鍍法 ； High-k ； 直接穿隧漏電流 ； HfO2薄膜

並列摘要

The evolution of IC manufacturing process and the device size will be getting smaller. It makes the SiO2 of gate becoming thinner, while the direct tunneling leakage current increase. The leakage current increase result the device which has the leakage current generation and power loss, this research was find out the new material “High-k” to replace SiO2. The dielectric layer of high-k is larger than SiO2 layer’s thickness several times at the same capacitances. It can reduce the direct tunneling leakage current effectively. Many studies aim that HfO2 is the most promising to replace SiO2 as the dielectric material of gate.In this study, use the DC magnetron sputtering method to prepare HfO2 thin films. The parameter include changing sputtering gas ratio (Ar:O2)、substrate temperature、annealing atmosphere、annealing time、improving the oxygen ratio (Ar:O2)、different Sc3+ doping quantity and self-Hf target to discuss. The results show the gas ratio (Ar:O2)=1:10 have the highest dielectric constant of 35.4. It can reduce the leakage current to 10-9 A/cm2 was employed in gas ratio (Ar:O2)=10:1、substrate temperature 300℃、gas ratio (Ar:O2)=1:1、annealing for 30 minutes in the Ar 600℃/O2 500℃ and Sc3+doped 6.95 atom%.

並列關鍵字

Sputtering ； High-K ； Leakage current ； HfO2

參考文獻

[1] J. Zeng, M. Zhang, Z. Song, L. Wan, J. Li, K. Li, Chenglu Lin, “Lead-zirconate titanate thin films deposited on silicon using a novel technique at low temperature,” Applied Surface Science, vol.148, 1999, pp137-141.

[2] X. G. Tang, H. L.W. Chan, A.L. Ding, and Q. R. Yin, “Processing effectes on themicrostructure and ferroelectric properties of Pb (Zr,Ti)O3 thin films preparedby sol-gel process,” Surface and Coatings Technology, vol.161, 2002, pp.169-173.

[3] H. T. Lue, C. Y. Liu, and T. Y. Tseng, “An Improved Two-Frequency Method of Capacitance Measurement for SrTiO3 as High-k Gate Dielectric,” IEEE Electron Device Letters, vol. 23, no. 9, 2002, pp.553-555.

[4] J. H. Joo, Y. C. Jeon, J. M. Seon, K. Y. Oh, J. S. Roh, and J. J. Kim, “Effects of post-annealing on the conduction properties of Pt/(Ba, Sr)TiO3/Pt capacitors for dynamic random access memory applications,” Japanese Journal of Applied Physics, vol.36, 1997, pp. 4382-4385.

[5] J. C. Shin, J. Park, C. S. Hwang, and H. J. Kim, “Dielectric and electrical properties of sputter grown (Ba, Sr)TiO3 thin films,” Japanese Journal of Applied Physics, vol.86, 1999, pp.L9-L12.