Abstract
A simple kinetic model is used to explain the observed dependence of the sputtering quantum yield on the laser fluence. The mechanism of sputtering presented here involves pairing of two holes against their repulsive Coulomb barrier, which depends on the concentration of photoexcited charge carriers through Debye screening. A threshold laser fluence is obtained at a concentration of photoexcited charge carriers that suppresses the barrier sufficiently to allow the pairing of holes at the surface bonds. The bonds are broken and atoms are ejected from the surface. The temperature dependence of the threshold laser fluence is discussed. Results agree qualitatively with experiments and existing theories.
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References
M. Georgiev: Revs. Solid State Sci. 4, 223 (1990)
N. Itoh: In Defect Processes Induced by Electronic Excitation in Insulators (World Scientific, Singapore 1989) p. 253
J.A. Van Vechten, A.D. Compaan: Solid State Commun. 39, 867 (1989)
M. Okigawa, K. Takayama, T. Nakayama, N. Itoh: Proc. 13th Int'l Cong. Defects in Semiconductors, ed. by L.C. Kimmerling, J.M. Parsey, Jr., p. 547 (1984)
Y. Kumazaki, Y. Nakai, N. Itoh: Phys. Rev. Lett. 59, 2883 (1983)
K. Hattori, N. Nakai, N. Itoh: To be published
T. Yamamoto, K. Hattori, Y. Nakai, N. Itoh, M. Szymonski: Rad. Effects Defect Solids 109, 213 (1989)
Y. Nakai, K. Hattori, N. Itoh: To be published
N. Itoh: Nucl. Instrum. Methods in Phys. Res. B 27, 155 (1987)
N. Itoh, T. Nakayama: Phys. Lett. A 92, 471 (1982)
N. Itoh, T. Nakayama, T.A. Tombrello: Phys. Lett. A 108, 480 (1982)
P.W. Anderson: Phys. Rev. Lett. 34, 953 (1975)
J. Singh, N. Itoh: Appl. Phys. A 51, 427 (1990)
J. Singh: Chem. Phys. Lett. 149, 447 (1988)
J. Singh, N. Itoh, V.V. Truong: Appl. Phys. A 49, 631 (1989)
J. Singh, N. Itoh: Chem. Phys. 148, 209 (1990)
T Holstein: Ann. Phys. 8, 325 (1958)
H. Sumi: To be published
K. Hattori: Private communication (1990)
S.I. Pekar: Issledovaniya po elektronnoi teorii kristallov (Moskva, GITTL 1951) (in Russian)
M. Georgiev: F′ Centers in Alkali Halides, Lect. Notes Phys., Vol. 298 (Springer, Berlin, Heidelberg 1988)
J.C. Philipps: Bonds and Bands in Semiconcutors (Academic, New York 1973)
M. Ueta, H. Kanzatki, K. Kobayashi, Y. Toyozawa, L. Hanamura (eds.): Excitonic Processes in Solids, Springer Ser. Solid-State Sci., Vol. 60 (Springer, Berlin, Heidelberg 1986)
M. Georgiev: Revista Mexicana de Fisica 31, 221 (1985)
J.A. Van Vechten: In Semicond Probed by Ultrafast Laser Spectroscopy, ed. R.R. Alfano (Academic, New York 1984) p. 45
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On leave of absence from: Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Lenin Boulevard, BG-1784 Sofia, Bulgaria