AVS 47th International Symposium
    Plasma Science and Technology Thursday Sessions
       Session PS1-ThA

Paper PS1-ThA10
Novel Technique to Enhance Etch Selectivity of Carbon ARC over PR based on O@sub 2@/CHF@sub 3@/Ar Gas Chemistry

Thursday, October 5, 2000, 5:00 pm, Room 310

Session: Plasma-Surface Interactions II
Presenter: J. Hong, Samsung Electronics, South Korea
Authors: J. Hong, Samsung Electronics, South Korea
J.S. Jeon, Samsung Electronics, South Korea
Y.B. Kim, Samsung Electronics, South Korea
T.-H. Ahn, Samsung Electronics, South Korea
Correspondent: Click to Email
New Anti-Reflective Coating (ARC), amorphous carbon (C-ARC) substitute for inorganic ARC (SiON) is gaining attention recently in DRAM process as device scales down requiring more fine control of submicron (<0.13µm) patterning. Parametric study of enhancing etch selectivity of C-ARC over photoresist was performed based on O@sub 2@/CHF@sub 3@/Ar gas chemistry in a Capacitively Coupled Plasma (CCP) tool. Etch rate of C-ARC is found to be strong dependent on the formation of hydrogen radicals in the plasma, heat treatment and deposition temperature of amorphous carbon. Fourier Transform IR (FTIR) analysis revealed that bonding structure transformation occurred in the carbon ARC from sp@sub 3@ tetrahedral structure to sp@sub 2@ graphite structure when amorphous carbon is subject to heat treatment in the furnace at 600°C for 15 minute leading to the boost in etch rate of C-ARC. High etch selectivity of C-ARC over photoresist (>0.8) was achieved with annealing of amorphous carbon. The presence of hydrogen radical in the plasma produced similar result with C-ARC phase transition from sp@sub 3@ to sp@sub 2@ resulting from hydrogen-hydrogen abstract reaction. Deposition temperature of C-ARC determined hydrogen content on the surface. Hydrogen behavior on the surface appeared to be dominant factor to control etch selectivity and surface reaction mechanism of amorphous carbon will be discussed.