AVS 47th International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS-TuP

Paper PS-TuP24
Effect of Temperature (or Heat) on the Etch Rate of Iridium and Platinum in CF@sub 4@/O@sub 2@ Plasma

Tuesday, October 3, 2000, 5:30 pm, Room Exhibit Hall C & D

Session: Poster Session
Presenter: F. Zhang, Sharp Laboratories of America, Inc.
Authors: H. Ying, Sharp Laboratories of America, Inc.
J.S. Maa, Sharp Laboratories of America, Inc.
F. Zhang, Sharp Laboratories of America, Inc.
S.T. Hsu, Sharp Laboratories of America, Inc.
Correspondent: Click to Email
Iridium and platinum films are often used as electrode materials in ferroelectric devices. In this work, we demonstrated that the substrate temperature plays an important role in the etching of iridium and platinum when etched in a CF@sub 4@/O@sub 2@ plasma. The etching was performed in an Electron Cyclotron Resonance (ECR) plasma reactor. The wafer was placed on a heated chuck during etching. Wafer temperature was maintained in the range of 70°C to 250°C before etching. An RF power was applied to the wafer chuck to generate a self-bias potential. At temperatures below 100°C, the iridium etch rate was low (~200 Å/min). The etch rate increased with the increase of temperature, and reached ~1500 Å/min at above 200°C. Platinum showed a low etch rate below 150°C, then also increased to ~1500 Å/min at higher temperature. In both cases, there is a transition from low etch rate to high etch rate. The transition occurred at a slightly higher temperature for the case of platinum etching. The increase of etch rate at higher temperature was believed due to the formation of volatile compound of IrF@sub 6@ and PtF@sub 6@.