Dependence of current-voltage characteristics on Al mole fraction in GaAs/Al x Ga 1−x As asymmetric double barrier structures

• Published in: Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures Vol. 15; no. 3; pp. 696 - 701
• Main Authors: Blue, L. J., Daniels-Race, T., Kendall, R. E., Schmid, C. R., Teitsworth, S. W.
• Format: Journal Article
• Language: English
• Published: 01-05-1997
• Subjects: (Al,Ga)As; GaAs
• ISSN: 0734-211X; 1520-8567
• DOI: 10.1116/1.589371

The effect of barrier Al mole fraction,
0.2⩽x⩽0.8
, on tunneling currents has been studied for a set of asymmetric GaAs/Al
x
Ga
1−x
As double barrier structures. The barrier widths of each sample were scaled so that barrier transmission coefficients for different samples should be approximately equivalent at the first resonant tunneling peak. Structures were grown by molecular beam epitaxy; by adjusting Ga and Al cell temperatures, the full range of Al mole fractions could be achieved in Al
x
Ga
1−x
As barrier layers while maintaining a nearly constant growth rate of about 1
μ
m/h. Current-voltage measurements are in agreement with theoretical estimates and indicate good sample quality.