AVS 52nd International Symposium
    Plasma Science and Technology Monday Sessions
       Session PS-MoP

Paper PS-MoP18
Characterization Methodologies for Unsaturated 1,3-C4F6 Plasma used to Investigate Aspect Ratio Dependent Etch and Etch Characteristics with Comparison to Saturated C-C4F8

Monday, October 31, 2005, 5:00 pm, Room Exhibit Hall C&D

Session: Plasma Science and Technology Poster Session
Presenter: T.L. Anglinmatumona, San Jose State University
Authors: T.L. Anglinmatumona, San Jose State University
C.T. Gabriel, Advanced Micro Devices
E. Allen, San Jose State University
Correspondent: Click to Email
The scaling of device features below 65 nm may encounter severe challenges such as the mass transport of CF2 and CF polymer precursors to the bottom of the feature due the generation of large molecular-weight radicals in saturated chemistries. As aspect ratios continue to increase due to the shrinking of the via hole diameter, saturated chemistries such as octafluorocyclobutane (c-C@sub 4@F@sub 8@) will no longer provide the etch performance required for ULSI. Hexafluorobutadiene (1,3-C@sub 4@F@sub 6@) is being proposed as an alternative gas to c-C@sub 4@F@sub 8@ for via etching in an inductively coupled plasma system. Profile slope, etch selectivity, CD bias and etch rates were investigated as a function of cathode temperature, rf bias power and chamber pressure. Optimum process conditions were identified based on a statistical design of experiment. Hexafluorobutadiene at optimized process conditions improved the etch parameters overall by 2X in comparison to c-C@sub 4@F@sub 8@. Aspect ratio dependent etching (ARDE) was reduced due to 1,3-C@sub 4@F@sub 6@ unsaturated bond configuration and improved process conditions.