Setup of a scanning near field infrared microscope (SNIM): imaging of sub-surface nano-structures in gallium-doped silicon.
We have realized a scanning near-field infrared microscope in the 3-4 microm wavelength range. As a light source, a tunable high power continuous wave infrared optical parametric oscillator with an output power of up to 2.9 W in the 3-4 microm range has been set up. Using scanning near field infrared microscopy (SNIM) imaging we have been able to obtain a lateral resolution of < or =30 nm at a wavelength of 3.2 microm, which is far below the far-field resolution limit of lambda/2. Using this "chemical nanoscope" we could image a sub-surface structure of implanted gallium ions in a topographically flat silicon wafer giving evidence for a near-field contrast. The observed contrast is explained in terms of the effective infrared reflection as a function of the sub-surface gallium doping concentration. The future use of the setup for nm imaging in the chemically important OH, N-H and C-H stretching vibration is discussed.
Physical Chemistry II, Ruhr-University Bochum, Germany.
Jean-Sébastien
JS
Samson
Götz
G
Wollny
Erik
E
Bründermann
Andreas
A
Bergner
Andreas
A
Hecker
Gerhard
G
Schwaab
Andreas Dirk
AD
Wieck
Martina
M
Havenith
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003198:Computer Simulation; D005708:Gallium / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D018613:Microscopy, Confocal / Q000295:instrumentation / Q000379:methods; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D012825:Silicon / Q000737:chemistry*; D019265:Spectroscopy, Near-Infrared / Q000295:instrumentation* / Q000379:methods*; D013499:Surface Properties
D005708:Gallium; D012825:Silicon