1995 Fiscal Year Final Research Report Summary
Developmental Research on Large Area Growth of Ferroelectric Thin Films with a High Growth Rate by MOCVD and Their Applications to Memory Device
| Project/Area Number |
06555094
|
|---|
| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Electronic materials/Electric materials
|
|---|
| Research Institution | KYOTO UNIVERSITY |
|---|
Principal Investigator |
SHIOSAKI Tadashi Kyoto University, Graduate School of Engineering Associate Professor, 工学研究科, 助教授 (80026153)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
OHNISHI Shingo Sharp.Co.VLSI Dev.Lab.Researcher, 超LSI開発研究所, 研究員
NAKAYA Kenichi Amaya Co.Ltd.Researcher, 技術第1部, 主任
SHIMIZU Masaru Himeji Inst.of Tech., Dept.of Electronics Assoc.Prof., 工学部, 助教授 (30154305)
|
|---|
| Project Period (FY) |
1994 – 1995
|
| Keywords | MOCVD / PZT / PLZT / large area growth / thin film / uniformity / memory device / fatigue |
|---|
| Research Abstract |
A 6-8 inch single wafer type MOCVD system for ferroelectric thin films was developed. Large area growth of Pb (Zr, Ti) 03 (PZT) and (Pb, La) (Zr, Ti) 03 (PLZT) thin films was performed by MOCVD on a 6-8 inch Si wafer. Highly uniform PZT thin films with a variation in film thickness of less than <plus-minus>1.2% were successfu lly grown on a 6-8 inch wafer. The variations in the Pb, Zr and Ti components were of less than <plus-minus>0.8, <plus-minus>0.8 and <plus-minus>1.1%, respectively. PZT films with variation in dielectric constant of less than <plus-minus>5.1% were also obtained on a 6 inch wafer. On a 6 inch wafer. PLZT films with a variation in film thickness of less than <plus-minus>1.5% were also grown. The growth rate of PZT and PLZT films was 30-40/min, which was not enough for the realization of the practical production of memory devices. In order to obtain the high growth rate, an improvement in the shape of gas nozzle should
The electrical properties of PZT thin films grown on Ir, IrO_2 and Ir/IrO_2 bottom electrodes and the effects of various top electrode materials on the electrical properties of these PZT films were investigated. The PZT thin film capacitors using Ir and IrO_2 electrodes showed no fatigue up to a switching cycle of 10^<11>. It was also found that annealing process after forming the upper electrode was one of key factors in determining the fatigue characteristics.
|
