AVS 47th International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS-WeP

Paper PS-WeP23
Plasma Etching of Lead Germanate (PGO) Ferroelectric Thin Film

Wednesday, October 4, 2000, 11:00 am, Room Exhibit Hall C & D

Session: Poster Session
Presenter: H. Ying, Sharp Laboratories of America, Inc.
Authors: H. Ying, Sharp Laboratories of America, Inc.
J.S. Maa, Sharp Laboratories of America, Inc.
T.K. Li, Sharp Laboratories of America, Inc.
F. Zhang, Sharp Laboratories of America, Inc.
S.T. Hsu, Sharp Laboratories of America, Inc.
Correspondent: Click to Email
The lead germanate (PGO) thin film has been proposed for FRAM devices, especially for one transistor memory cell (1T) application. To realize such application, it is important to etch/pattern such thin film. In this work, plasma etching of PGO thin films was investigated by using chlorine or fluorine gas chemistries in an Electron Cyclotron Resonance (ECR) plasma reactor. Etch rates were studied as a function of etching conditions. The PGO etch rate of 600~650 Å/min was achieved by using a gas mixture of Cl@sub 2@ and Ar. In a pure Ar plasma, the PGO etch rate was significantly lower than that in a Cl@sub 2@/Ar plasma. The etching of silicon dioxide showed a similar trend under the same plasma conditions, however, the silicon oxide etch rate was much lower (~400 Å/min) than the PGO etch rate. In a CF@sub 4@/Ar plasma, the PGO etching behaves quite differently from the etching of silicon dioxide. While the silicon oxide etch rate increases with the CF@sub 4@ concentration, the PGO etch rate tapered off after the CF@sub 4@ concentration reached ~15%. In addition, similar to plasma etching of many other materials, the etch rate of PGO material increases as the RF bias power and/or the microwave power increases. The PGO etch rate decreases as the process pressure increases. Plasma etching induced damage to PGO thin film will also be discussed.