The growth of AlInAsSb has not been extensively studied, perhaps because of the large miscibility gap predicted for these alloys. See K. Onabe, NEC Res. Dev. 72, 1 (1984).
Groups at the University of Houston/University of North Texas (D. Washington, T. Hogan, P. Chow, T. Golding, C. Littler, and U. Kirschbaum, J. Vac. Sci. Technol. B16 1385 (1998); R. Lukic-Zrnic, D. W. Stokes, C. L. Littler, and T. D. Golding, Semicond. Sci. Technol. 16, 353 (2001)) and HRL LABS (D. H. Chow, Y. H. Zhang, R. H. Miles, and H. L. Dunlap, J. Cryst. Growth 150, 879 (1995)) examined AlInAsSb lattice-matched to GaSb substrates. The Texas group controlled the quaternary composition by adjusting the Al:In and As:Sb flux ratios, while the HRL LABS group grew superlattices of the binary materials InAs and AlSb.
A group at U.C.S.B (S. K. Mathis, K. H. A. Lau, A. M Andrews, E. M. Hall, G. Almuneau, E. L. Hu, and J. S. Speck, J. Appl. Phys. 89, 2458 (2001)) examined AlInAsSb alloys lattice-matched to InP substrates. As with the Texas group, quaternary composition was controlled by adjusting the Al:In and As:Sb flux ratios.
Finally, groups at Lincoln Lab/MIT (G. W. Turner, M. J. Manfra, H. K. Choi, and M. K. Connors, J. Cryst. Growth 175/176, 825 (1997)) and Université de Montpellier II (A. Wilk, B. Fraisse, P. Christol, G. Boissier, P. Grech, M. El Gazouli, Y. Rouillard, A. N. Baranov, and A. Joullié, J. Cryst. Growth 227/228, 586 (2001)) examined AlINAsSb alloys on InAs substrates. Both of these groups also controlled the quaternary composition by adjusting the Al:In and As:Sb flux ratios. The Lincoln Lab/MIT group grew a tensile-strained alloy, while the Montpellier group studied a lattice-matched alloy, but both groups incorporated relatively small Al mole fractions (15% and 12%, respectively).
Rather than grow the AlInAsSb quaternary directly, as most groups have done, or as a digital binary superlattice, a technique of growing a ternary/quaternary superlattice is disclosed presently. The overall composition may be controlled by adjusting the As:Sb flux ratio and by modulating the Sb beam.
The disclosed technique may allow access to a wider range of quaternary compositions than may be possible with a digital binary superlattice.
The disclosed technique may further be applicable to manufacturing electronic and optoelectronic devices such as, for example, InAs-channel HEMTs, InAs HBTs, and laser diodes which may require semiconductor materials that are lattice-matched to InAs.
The growth of alloys according to the disclosed technique may also impose an artificial, short-period order, which may frustrate the tendency of the film to dissociate into more stable components.
USPTO Backgrounds
USPTO Backgrounds