Influence of the SiO2 layer thickness on the degradation of HfO2/SiO2 stacks subjected to static and dynamic stress conditions

✍ Scribed by E. Amat; R. Rodríguez; M. Nafría; X. Aymerich; J.H. Stathis

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 144 KB
• Volume: 47
• Category: Article
• ISSN: 0026-2714
• DOI: 10.1016/j.microrel.2007.01.003

✦ Synopsis

The substitution of the SiO 2 gate oxide in MOS devices by a material with a high-k dielectric constant is being deeply studied nowadays to solve the problem of the leakage currents that appear with the progressive scaling of SiO 2 thickness. To improve the quality of the high-k/Si interface a very thin SiO 2 film is grown between both materials. In this work, HfO 2 /SiO 2 stacks with different SiO 2 thickness were subjected to different types of stress (static and dynamic) to analyze the effect of this interfacial layer of SiO 2 in the degradation of the stack. The results show that the dielectric degradation depends on the stress applied and that the thickness of the SiO 2 interfacial layer influences the advanced stages of the stack degradation.