Stress imagining of semiconductor surface by tip-enhanced Raman spectroscopy.
Tip-enhanced Raman imaging of strained silicon reveals the property of nanoscale stress imposed on the lattice. Our approach relies on the highly localized excitation provided by a metallized tip. Surface sensitive detections in nanoscale are realized by a reflection-mode configuration combined with 442-nm excitation and a silver-coated silicon nitride tip. The background signals from an underlying silicon germanium layer and a tip are well suppressed. The quantitative stress analysis is made on the basis of the Raman shift of the Si-Si phonon mode. We succeeded in visualizing the localized stress with a spatial resolution down to 25 nm whereas a conventional micro Raman technique provides only a uniform image because of the averaging effect within a diffraction-limited focused spot.
Saito
Y
Y
RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Motohashi
M
M
Hayazawa
N
N
Kawata
S
S