The complex refractive index of SiGe alloys at 632.8 nm has been measured as a function of the Ge concentration using in situ ellipsometry while the material is slowly removed from a silicon substrate using reactive‐ion etching (RIE). Homogeneous, strained epitaxial SiGe films on silicon substrates were used. The Ge concentration was obtained by Rutherford backscattering. If an unknown SiGe structure is etched with RIE, in situ ellipsometry yields combinations of the ellipsometric angles Ψ and Δ with time. Starting at the Si substrate, these points are, on a point‐to‐point basis, converted into combinations of complex refractive index and depth in a numerical procedure. For this inversion of the ellipsometry equations, the known relation between the real and the imaginary part of the refractive index of SiGe is used. Finally the refractive indices are converted into Ge concentrations. Thus the depth profile of the Ge concentration in an unknown epitaxial SiGe structure can be inferred from an in situ ellipsometric measurement during RIE of the unknown structure. The obtained resolutions in depth and Ge concentration are 0.3 nm and 0.3%, respectively.
Skip Nav Destination
Article navigation
15 June 1993
Research Article|
June 15 1993
Depth profiling of the Ge concentration in SiGe alloys using in situ ellipsometry during reactive‐ion etching
G. M. W. Kroesen;
G. M. W. Kroesen
IBM Research Division, Thomas J. Watson Research Center, Yorktown Heights, New York 10598
Search for other works by this author on:
G. S. Oehrlein;
G. S. Oehrlein
IBM Research Division, Thomas J. Watson Research Center, Yorktown Heights, New York 10598
Search for other works by this author on:
E. de Frésart;
E. de Frésart
IBM Research Division, Thomas J. Watson Research Center, Yorktown Heights, New York 10598
Search for other works by this author on:
M. Haverlag
M. Haverlag
IBM Research Division, Thomas J. Watson Research Center, Yorktown Heights, New York 10598
Search for other works by this author on:
J. Appl. Phys. 73, 8017–8026 (1993)
Article history
Received:
March 20 1992
Accepted:
January 11 1993
Citation
G. M. W. Kroesen, G. S. Oehrlein, E. de Frésart, M. Haverlag; Depth profiling of the Ge concentration in SiGe alloys using in situ ellipsometry during reactive‐ion etching. J. Appl. Phys. 15 June 1993; 73 (12): 8017–8026. https://doi.org/10.1063/1.353916
Download citation file:
Sign in
Don't already have an account? Register
Sign In
You could not be signed in. Please check your credentials and make sure you have an active account and try again.
Sign in via your Institution
Sign in via your InstitutionPay-Per-View Access
$40.00
Citing articles via
A step-by-step guide to perform x-ray photoelectron spectroscopy
Grzegorz Greczynski, Lars Hultman
GaN-based power devices: Physics, reliability, and perspectives
Matteo Meneghini, Carlo De Santi, et al.
Nonempirical semilocal density functionals for correcting the self-interaction of polaronic states
Stefano Falletta, Alfredo Pasquarello