TIME AND TEMPERATURE INFLUENCE OVER GRADED BAND-GAP ALXGA1-XAS LAYERS

Graded band-gap Al(x)Ga(1-x)As layers were grown using isothermal liquid phase epitaxy techniques together with saturated solutions. The effects of time and temperature of contact between liquid solutions and solid substrates over grown layers are studied. The Al depth profiles, as measured by secondary ion mass spectroscopy analysis, show that: (a) the thickness of the grown layer increases rapidly at the contact starting moments and it saturates in a few minutes, (b) the Al surface concentration increases with the contact time at the beginning of the process and then it saturates, (c) the thickness of the layer decreases if the temperature increases. Finally, for this last new find we develop a tentative explanation based on an etch-diffusion-regrowth mechanism.