Real-time Optical Diagnostics For Measuring And Controlling Epitaxial Growth

We summarize recent applications of two real-time optical diagnostic techniques, reflectance difference spectroscopy (RDS) and spectroellipsometry (SE), to epitaxial growth on GaAs and atomic layer epitaxy (ALE) in particular. Using RDS, we obtain the first real-time spectroscopic data of the evolution of the (001) GaAs surface to cyclic and non-cycle exposures of atmospheric pressure H2, H2 and trimethylgallium, and H2 and arsine, which simulate growth by ALE. None of our observations is consistent with any previously proposed simple model, emphasizing the necessity of real-time measurements for the analysis of complex surface reactions. Using SE we have constructed a closed-loop system for controlling the compositions of AlxGa1-xAs layers grown by chemical beam epitaxy. We have produced various graded-compositional structures, including parabolic quantum wells 200 Å wide where the composition was controlled by analysis of the running outermost 3 Å (about 1 monolayer) of depositing material. © 1993.22501/02/152631Goodman, Pessa, (1986) J. Appl. Phys., 60, p. R65. , and references cited thereinOzeki, Ohtsuka, Sakuma, Kodama, (1991) J. Cryst. Growth, 107, p. 102Ozeki, Mochizuki, Ohtsuka, Kodama, (1988) Appl. Phys. Lett., 53, p. 1509Nishizawa, Kurabayashi, Abe, Sakurai, Gallium arsenide thin films by low-temperature photochemical processes (1987) Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 5, p. 1572Yu, Buchan, Souda, Kuech, Surface Chemistry and Mechanism of Atomic Layer Growth of GaAs (1991) MRS Proceedings, 222, p. 3Creighton, Banse, The Surface Chemistry of GaAs Atomic Layer Epitaxy (1991) MRS Proceedings, 222, p. 15Aspnes, Harbison, Studna, Florez, (1987) Phys. Rev. Lett., 59, p. 1687Aspnes, Harbison, Studna, Florez, Application of reflectance difference spectroscopy to molecular-beam epitaxy growth of GaAs and AlAs (1988) Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 6, p. 1327Kobayashi, Horikoshi, (1989) Jpn. J. Appl. Phys., 28, p. L1880Kobayashi, Horikoshi, Pyrolysis of Trimethylgallium on (001) GaAs Surface Investigated by Surface Photo-Absorption (1991) Japanese Journal of Applied Physics, 30, p. L319Aspnes, Quinn, Gregory, (1990) Appl. Phys. Lett., 57, p. 2707Aspnes, Quinn, Tamargo, Pudensi, Schwarz, Brasil, Nahory, Gregory, (1992) Appl. Phys. Lett., 60, p. 1244Aspnes, Kamiya, Tanaka, Bhat, Atomic layer epitaxy on (001) GaAs: Real-time spectroscopy (1992) Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 10, p. 1725Kamiya, Aspnes, Tanaka, Florez, Harbison, Bhat, (1992) Phys. Rev. Lett., 68, p. 627Kamiya, Aspnes, Florez, Harbison, (1992) Phys. Rev. B, 46, p. 15894Gomyo, Suzuki, Iijima, (1988) Phys. Rev. Lett., 60, p. 2645Froyen, Zunger, (1991) Phys. Rev. Lett., 59, p. 324Chen, Stringfellow, (1991) Appl. Phys. Lett., 59, p. 324Chiu, (1989) Appl. Phys. Lett., 55, p. 1244Creighton, (1990) Surf. Sci., 234, p. 287Memmert, Yu, (1990) Appl. Phys. Lett., 56, p. 1883Aspnes, Colas, Studna, Bhat, Koza, Keramidas, (1988) Phys. Rev. Lett., 61, p. 2782Reflectance–difference studies of organometallic chemical vapor deposition growth transients on (001) GaAs (1989) Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 7, p. 711Farrell, Harbison, Peterson, Molecular-beam epitaxy growth mechanisms on GaAs(100) surfaces (1987) Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 5, p. 1482Annapragada, Salim, Jensen, Ftir Studies Of Organometallic Surface Chemistry Relevant To Atomic Layer Epitaxy. (1991) MRS Proceedings, 222, p. 81Studna, Aspnes, Florez, Wilkens, Ryan, Low-retardance fused-quartz window for real-time optical applications in ultrahigh vacuum (1989) Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 7, p. 3291Aspnes, Studna, (1975) Appl. Opt., 14, p. 220(1978) Rev. Sci. Instrum., 49, p. 291Aspnes, Bhat, Colas, Florez, Gregory, Harbison, Kamiya, Wassermeier, Real-Time Optical Diagnostics For Measuring And Controlling Epitaxial Growth (1991) MRS Proceedings, 222, p. 63. , 2nd ed