Kinetics of photoresist etching in an electron cyclotron resonance plasma

Journal Article · Wed Aug 15 04:00:00 EDT 1990 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.346598· OSTI ID:6492547

Carl, D A; Hess, D W ^[1]; Lieberman, M A ^[2]

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1. Department of Chemical Engineering, University of California, Berkeley, CA (USA)
2. Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA (USA)

An electron cyclotron resonance plasma processing system was used to etch hardbaked KTI-820 photoresist from single crystal silicon wafers, silicon dioxide films and patterned multilayer structures. Etch rates of 1500 nm/minute were observed at a substrate temperature below 373 K in a {ital P}{sub forward}=750 W, 0.13-Pa ECR oxygen plasma with no applied substrate bias. The etch rate increased linearly with increasing power from {ital P}{sub forward}=300--750 W. Etch rate was a complicated function of pressure and residence time, but a modified adsorption-reaction-ion-stimulated desorption rate expression could be used to fit the data. Etch rates decreased for increasing oxygen residence time at low operating pressures due to a combination of polymeric film formation of reaction products and reactant (atomic oxygen) depletion. Maximum etch rates were observed at approximately 0.13 Pa for all residence times. Multilayer photoresist structures were etched at various pressures as well as at a 45{degree} angle to the incident plasma stream. Etch profiles for the variable angle runs indicated that the etch rate was strongly dependent on ion flux. Etch anisotropy increased with decreasing pressure, consistent with increased ion bombardment energy. The degree of anisotropy was, however, limited due to a non-normal component of ion energy, which has been interpreted previously as an ion temperature.

• DOE Contract Number: FG03-87ER13727
• OSTI ID: 6492547
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 68:4; ISSN JAPIA; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ADSORPTION
ANISOTROPY
CHALCOGENIDES
COLLISIONS
CYCLOTRON RESONANCE
DESORPTION
ELECTRON CYCLOTRON-RESONANCE
ELEMENTS
ETCHING
ION COLLISIONS
OXIDES
OXYGEN COMPOUNDS
PLASMA
POLYMERS
PRESSURE DEPENDENCE
RESONANCE
SEMIMETALS
SILICON
SILICON COMPOUNDS
SILICON OXIDES
SORPTION
SURFACE FINISHING
TIME DEPENDENCE