Silicon impurity-induced layer disordering of AlGaN/AlN superlattices

Impurity-induced layer disordering is demonstrated in Al0.1Ga0.9N/AlN superlattices grown by metal-organic vapor phase epitaxy. During growth at temperatures as low as 885 degrees C and under post growth annealing at 1000 degrees C in N-2 the heterointerfaces of Si-doped (Si concentration >8 x 10(19) cm(-3)) superlattices exhibit layer disordering (intermixing) while the unintentionally doped superlattices remain stable. Shifts in the intersubband energy transitions and scanning transmission electron microscope images showing changes in the layer abruptness are used to verify layer disordering due to Si diffusion in Al0.1Ga0.9N/AlN superlattices. (C) 2010 American Institute of Physics. [doi:10.1063/1.3478002]