AVS 53rd International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS1+MS+NM-TuM

Paper PS1+MS+NM-TuM10
High Aspect Ratio (>10:1) Amorphous Carbon Layer Etching Using Soft Etch Capability in a High Frequency Capacitive Coupled Plasma Source Dielectric Etch Chamber

Tuesday, November 14, 2006, 11:00 am, Room 2009

Session: Plasma Patterning
Presenter: S. Sung, Applied Materials
Authors: S. Sung, Applied Materials
J. Wang, Applied Materials
S. Ma, Applied Materials
Correspondent: Click to Email
Amorphous carbon layer (ACL) such as advanced patterning film (APF) is generally selected as one possible hard mask material for variety of dielectric etching application beyond 65 nm technology nodes to improve the etch process margin from reduction of resist thickness. Most of the APF etching application for DRAM, flash and logic technology are done typically on <800 nm ACL film thickness as a mask for contact or mask open dielectric etch application. However, it is necessary to evaluate the APF layer etching capability on >1 µm film thickness to enable specific integration scheme of nanotechnology. The challenges of etching high aspect ratio ACL features are bowing prevention during etching, hard mask selectivity and the etch rate improvement for throughput concern. In this paper, high aspect ratio (HAR) contact through ACL layer is developed by soft etching capability using high frequency source plasma etch chamber. This development work was done in the dielectric etch chamber consisting of the superimposed dual bias power and a capacitive coupled source power > 100 MHz, which can be operated in either low density process regime for higher resist selectivity, or in high density process regime for profile control, resist integrity, minimal striations and effective chamber cleaning. With high frequency source power, fast etch rate >6000 Å/min of ACL has achieved with minimum hard mask corner chopping from small plasma self bias. All the process trends are characterized with profile control, hard mask selectivity and etch rate.