Abstract

An optical technique is described for detecting and measuring thicknesses of adsorbed films with subangstrom sensitivity. The technique relies on optical interference from an antireflecting thin-film structure that is predeposited on a transparent cell window: the reflectivity of the window depends linearly on the thickness of the molecular layer adsorbed from the gas in the cell.

© 1981 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. J. G. Dash, Films on Solid Surfaces (Academic, New York, 1975).
  2. A. M. Bradshaw, F. M. Hoffmann, Surf. Sci. 72, 513 (1978).
    [CrossRef]
  3. V. Daneu, Appl. Opt. 14, 962 (1975).
    [PubMed]
  4. O. S. Heavens, Optical Properties of Thin Solid Films (Dover, New York, 1976).
  5. This result, independent of the indices used for AR film and substrate, also holds for a complex transparent multilayer structure, for which the detuning from Rmin to Ropt is achieved by a change in the thickness of the outermost film.
  6. G. Quentel, R. Kern, Surf. Sci. 55, 545 (1976).
    [CrossRef]
  7. D. J. Ehrlich, R. M. Osgood, Chem. Phys. Lett. 79, 381 (1981).
    [CrossRef]
  8. L. I. Osipow, Surface Chemistry (Krieger, Huntington, W. Va., 1972).

1981

D. J. Ehrlich, R. M. Osgood, Chem. Phys. Lett. 79, 381 (1981).
[CrossRef]

1978

A. M. Bradshaw, F. M. Hoffmann, Surf. Sci. 72, 513 (1978).
[CrossRef]

1976

G. Quentel, R. Kern, Surf. Sci. 55, 545 (1976).
[CrossRef]

1975

Bradshaw, A. M.

A. M. Bradshaw, F. M. Hoffmann, Surf. Sci. 72, 513 (1978).
[CrossRef]

Daneu, V.

Dash, J. G.

J. G. Dash, Films on Solid Surfaces (Academic, New York, 1975).

Ehrlich, D. J.

D. J. Ehrlich, R. M. Osgood, Chem. Phys. Lett. 79, 381 (1981).
[CrossRef]

Heavens, O. S.

O. S. Heavens, Optical Properties of Thin Solid Films (Dover, New York, 1976).

Hoffmann, F. M.

A. M. Bradshaw, F. M. Hoffmann, Surf. Sci. 72, 513 (1978).
[CrossRef]

Kern, R.

G. Quentel, R. Kern, Surf. Sci. 55, 545 (1976).
[CrossRef]

Osgood, R. M.

D. J. Ehrlich, R. M. Osgood, Chem. Phys. Lett. 79, 381 (1981).
[CrossRef]

Osipow, L. I.

L. I. Osipow, Surface Chemistry (Krieger, Huntington, W. Va., 1972).

Quentel, G.

G. Quentel, R. Kern, Surf. Sci. 55, 545 (1976).
[CrossRef]

Appl. Opt.

Chem. Phys. Lett.

D. J. Ehrlich, R. M. Osgood, Chem. Phys. Lett. 79, 381 (1981).
[CrossRef]

Surf. Sci.

G. Quentel, R. Kern, Surf. Sci. 55, 545 (1976).
[CrossRef]

A. M. Bradshaw, F. M. Hoffmann, Surf. Sci. 72, 513 (1978).
[CrossRef]

Other

L. I. Osipow, Surface Chemistry (Krieger, Huntington, W. Va., 1972).

J. G. Dash, Films on Solid Surfaces (Academic, New York, 1975).

O. S. Heavens, Optical Properties of Thin Solid Films (Dover, New York, 1976).

This result, independent of the indices used for AR film and substrate, also holds for a complex transparent multilayer structure, for which the detuning from Rmin to Ropt is achieved by a change in the thickness of the outermost film.

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (4)

Fig. 1
Fig. 1

Optical setup.

Fig. 2
Fig. 2

(a) Thin layer adsorbed on a single-film antireflection coating, (b) Reflectivity of AR structure versus AR-film thickness. Solid curve, without adsorbed layer; dotted curve, with adsorbed layer.

Fig. 3
Fig. 3

(a) Lower curves: optically measured adsorption isotherms for Si(CH3)4 and C2H5OH on a 200-Å film of sputtered Si for a probe-beam wavelength λ = 1.15 μm. Upper curve: adsorption isotherm for Si(CH3)4 on sputtered Si measured with a quartz microbalance. (b) Optically measured adsorption isotherms for Si(CH3)4 and C2H5OH on a 1500-Å film of SiO2 for a probe-beam wavelength λ = 6328 Å.

Fig. 4
Fig. 4

Thermal desorption measurements for C2H5OH on SiO2 obtained at λ = 6328 Å. The solid curves are calculated from the BET theory.

Equations (2)

Equations on this page are rendered with MathJax. Learn more.

δ = n 2 1 n 0 2 1 d .
Δ R R opt = ± 2 π n 2 1 R opt d λ ;

Metrics