Title :
Development of stable PZT sputtering process using ex-situ crystallization and PZT/Pt interface control technique
Author :
Yamakawa, K. ; Arisumi, O. ; Okuwada, K. ; Tsutsumi, K. ; Katata, T.
Author_Institution :
Microelectron. Eng. Lab., Toshiba Corp., Yokohama, Japan
Abstract :
Precise control of Pb content in sputter-deposited amorphous PZT films was achieved by optimization of substrate temperature; substrate and shield potential, sputtering condition, and target surface condition. Pb, Ti and oxygen at PZT/Pt interfaces have important roles in amorphous-perovskite phase transformation and their effects were used in seeding techniques. A variety of grain sizes and ⟨111⟩ preferred orientation was obtained by 2 step depositions using Ti seed layers and initial Ar/O2 sputter-deposited seed layers. 2Pr of 40 uC/cm2 was obtained over 6" Si substrates. Differences in amorphous structure were found important in PZT crystallization. Seeding technique and an improved sputtering system make it possible to apply the PZT sputtering technique for FeRAM fabrication. Pb behavior during crystallization and post thermal processes was analyzed and modeled to understand electrical properties
Keywords :
amorphous state; crystallisation; ferroelectric materials; ferroelectric thin films; grain size; interface structure; lead compounds; metal-insulator boundaries; noncrystalline structure; platinum; sputter deposition; stoichiometry; texture; 6 in; Ar; Ar/O2 sputter-deposited seed layers; FeRAM fabrication; O2; PZT-Pt; PZT/Pt interface control technique; Pb content; PbZrO3TiO3-Pt; Si; Ti seed layers; amorphous structure; amorphous-perovskite phase transformation; crystallization; ex-situ crystallization; grain sizes; optimization; post thermal processes; preferred orientation; seeding techniques; shield potential; sputter-deposited amorphous PZT films; sputtering condition; stable PZT sputtering process; substrate temperature; target surface condition; Amorphous materials; Argon; Crystallization; Fabrication; Ferroelectric films; Grain size; Nonvolatile memory; Random access memory; Sputtering; Temperature control;
Conference_Titel :
Applications of Ferroelectrics, 1998. ISAF 98. Proceedings of the Eleventh IEEE International Symposium on
Conference_Location :
Montreux
Print_ISBN :
0-7803-4959-8
DOI :
10.1109/ISAF.1998.786660
