title: Nanoscale residual stress-field mappingaround nanoindents in SiCby IR s-SNOM and confocal Raman microscopy.
abstract: We map a nanoindent in a silicon carbide (SiC) crystal by infrared (IR) scattering-type scanning near-field optical microscopy (s-SNOM) and confocal Raman microscopy and interpret the resulting images in terms of local residual stress-fields. By comparing near-field IR and confocal Raman images, we find that the stress-induced shifts of the longitudinal optical phonon-frequencies (LO) and the related shift of the phonon-polariton near-field resonance give rise to Raman and s-SNOM image contrasts, respectively. We apply single-frequency IR s-SNOM for nanoscale resolved imaging of local stress-fields and confocal Raman microscopy to obtain the complete spectral information about stress-induced shifts of the phonon frequencies at diffraction limited spatial resolution. The spatial extension of the local stress-field around the nanoindent agrees well between both techniques. Our results demonstrate that both methods ideally complement each other, allowing for the detailed analysis of stress-fields at e.g. material and grain boundaries, in Micro-Electro-Mechanical-Systems (MEMS), or in engineered nanostructures.
authors.affiliation: Department of Earth and Environmental Sciences, Ludwig-Maximilians-Universität München, Theresienstr. 41, 80333 Munich, Germany. gigler@lmu.de
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Gigler
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Huber
authors.forename: Michael
authors.initials: M
authors.lastname: Bauer
authors.forename: Alexander
authors.initials: A
authors.lastname: Ziegler
authors.forename: Rainer
authors.initials: R
authors.lastname: Hillenbrand
authors.forename: Robert W
authors.initials: RW
authors.lastname: Stark
mesh_terms: D017554:Carbon Compounds, Inorganic / Q000737:chemistry*; D055119:Elastic Modulus; D006244:Hardness; D006245:Hardness Tests / Q000379:methods*; D008422:Materials Testing / Q000379:methods*; D018625:Microscopy, Atomic Force / Q000379:methods*; D018613:Microscopy, Confocal / Q000379:methods*; D017655:Silicon Compounds / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties
chemical_list: D017554:Carbon Compounds, Inorganic; D017655:Silicon Compounds; C022088:silicon carbide