High-k HfxZr1-xO2 Ferroelectric Insulator by Utilizing High Pressure Anneal

Abstract

In this article, we report the fabrication of Zr-rich high-k ferroelectric hafnium zirconium oxide (HZO) capacitor with TiN as the top and bottom electrodes demonstrating an equivalent oxide thickness (EOT) of 5.7 angstrom and remanent polarization (P-r) of similar to 16 mu C/cm(2). High-k value and low EOT was achieved by utilizing multiphase region of HZO as well as high pressure post metallization annealing (HPPMA). Despite the high-k value of Zr-rich HZO films, the emergence of multiphase region at higher physical thickness when annealed using rapid thermal annealing (RTA) limits its EOT value. On the contrary, multiphase emerges at a smaller physical thickness in HPPMA due to the formation of more o-phase as revealed by grazing incidence X-ray diffractometer (GIXRD). The smaller physical thickness of HPPMA together with the demonstration of significantly higher dielectric constant (>50) by HZO in the vicinity of multiphase, was therefore, found to be very effective in reducing the EOT.