| AVS 54th International Symposium | |
| Thin Film | Monday Sessions |
| Session TF-MoM |
| Session: | Atomic Layer Deposition and Applications |
| Presenter: | S. Bang, Hanyang University, Korea |
| Authors: | S. Bang, Hanyang University, Korea S. Lee, Hanyang University, Korea S. Jeon, Hanyang University, Korea S. Kwon, Hanyang University, Korea W. Jeong, Hanyang University, Korea I. Kim, Hanyang University, Korea H. Jeon, Hanyang University, Korea |
| Correspondent: | Click to Email |
Zirconium and hafnium-based dielectric materials have been widely studied as a gate oxide for the next generation of CMOS technology due to high dielectric constant, a relatively wide band gap and thermodynamic stability on Si. However, ZrO2 and HfO2 films can be crystallized at the temperature below 500°C. For gate dielectrics, an amorphous structure is always preferred to a polycrystalline structure, because a crystalline film can induce high grain boundary leakage current and lead to non-uniformities in k value and in film thickness. Thus, efforts have been made to improve the properties of HfO2 and ZrO2 by adding different elements such as Si, Al, N, Ti, and Ta. Addition of Si, Al, or N allows for the increased crystallization temperature of HfO2 and ZrO2. However, there is a drawback of a lowered dielectric constant. Although the addition of Ti can increase dielectric constant of HfO2 and/or ZrO2 films, it can degrade the leakage current characteristics by decreasing a band offset. The addition of metal elements to improve the quality of high-k oxide film, without reducing dielectric constant and increasing leakage current, is important. ZrO2 has similar chemical structure to HfO2 and is completely miscible with HfO2. Zr addition can yield stability to the higher dielectric constant tetragonal phase. In this study, we deposited ZrxHf1-xOy films varying with the content of Zr on Si substrates by adding Zr into HfO2 film using atomic layer deposition (ALD) process and investigated its physical and electrical characteristics. Auger electron spectroscopy (AES) and X-ray Photoelectron Spectroscopy (XPS) were used to analyze the chemical composition and bonds. AES and RBS data indicated that the composition ratio of ZrxHf1-xOy films is varied as the Zr content change in those films. And X-ray diffraction (XRD) was used to analyze the structure properties of ZrxHf1-xOy films. The capacitance values of ZrxHf1-xOy films showed about 415 ~ 620pF/cm2 on capacitance-voltage (C-V) measurement. For the analysis of other electrical properties, C-V and current-voltage (I-V) analyses were measured to evaluate the dielectric constant, EOT, and leakage current of ZrxHf1-xOy films, etc.