title: Pulse-biased etching of Si3N4-layer in capacitively-coupled plasmas for nano-scale patterning of multi-level resist structures.
abstract: Pulse-biased plasma etching of various dielectric layers is investigated for patterning nano-scale, multi-level resist (MLR) structures composed of multiple layers via dual-frequency, capacitively-coupled plasmas (CCPs). We compare the effects of pulse and continuous-wave (CW) biasing on the etch characteristics of a Si3N4 layer in CF4/CH2F2/O2/Aretch chemistries using a dual-frequency, superimposed CCP system. Pulse-biasing conditions using a low-frequency power source of 2 MHz were varied by controlling duty ratio, period time, power, and the gas flow ratio in the plasmas generated by the 27.12 MHz high-frequency power source. Application of pulse-biased plasma etching significantly affected the surface chemistry of the etched Si3N4 surfaces, and thus modified the etching characteristics of the Si3N4 layer. Pulse-biased etching was successfully applied to patterning of the nano-scale line and space pattern of Si3N4 in the MLR structure of KrF photoresist/bottom anti-reflected coating/SiO2/amorphous carbon layer/Si3N4. Pulse-biased etching is useful for tuning the patterning of nano-scale dielectric hard-mask layers in MLR structures.
authors.forename: Hyelim
authors.initials: H
authors.lastname: Lee
authors.forename: Sechan
authors.initials: S
authors.lastname: Kim
authors.forename: Gyuhyun
authors.initials: G
authors.lastname: Choi
authors.forename: Nae-Eung
authors.initials: NE
authors.lastname: Lee
mesh_terms: D036103:Nanotechnology; D058626:Plasma Gases; D017655:Silicon Compounds / Q000737:chemistry*
chemical_list: D058626:Plasma Gases; D017655:Silicon Compounds; C032734:silicon nitride