AVS 47th International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS+MS-WeM

Paper PS+MS-WeM5
Effect of Oxide to Nitride Etch Selectivity on Plasma Induced Charging Damage

Wednesday, October 4, 2000, 9:40 am, Room 311

Session: Plasma-Induced Damage
Presenter: S. Ma, Applied Materials Inc.
Authors: S. Ma, Applied Materials Inc.
C. Björkman, Applied Materials Inc.
R. Wang, Applied Materials Inc.
L. Zhang, Applied Materials Inc.
H. Shan, Applied Materials Inc.
R. Ramanathan, Conexant Systems
Correspondent: Click to Email
Nitride layers are widely used for dual-damascene, self-aligned contact and border-less contact dielectric etch process as etch stop layers. It is also believed that such etch stop layer on top of metal electrode can also serve as plasma charging damage protection layer. This study shows no relationship between the dielectric to nitride etch selectivity and plasma induced charging damage. A Magnetically Enhanced Reactive Ion Etching (MERIE) chamber is used for this study with 0.25 um technology devices. In fluorine contained etching chemistry, strong recipe dependence on plasma charging damage is found regardless of the dielectric to nitride etch selectivity. A model of leaky nitride with charge built up on via hole bottom is proposed to explain the phenomena. In pure oxygen chemistry for in-situ polymer removal, plasma induced charging damage depends on the remaining nitride thickness. It is found that power is the most sensitive parameter than B-field, pressure, overetch and gas species to control damage. A mechanism is also proposed to explain the role of polymer formation and removal on top of nitride stop layer to plasma charging damage sensitivity