The interdiffusion of cations and anions on their respective sub-lattices in superlattices was quantitatively analyzed. Double-crystal X-ray diffraction, and simulated rocking curves that were based upon dynamic diffraction theory, were used to measure the interface strain that developed during rapid thermal annealing. Low-temperature photoluminescence measurements were also used to assess interdiffusion, via changes in the ground-state transition energy of the superlattice. Simulations involving suitably selected interdiffusion coefficients permitted accurate fitting of the interface strain profile and photoluminescence transition energies. The interdiffusion behavior of the present InGaAs/InP superlattices, with and without P-doped SiO2 capping, was analyzed by using this method. Interdiffusion coefficients of 5.8 x 10-17 and 2.9 x 10-17cm2/s were deduced for the anion and cation sub-lattices, respectively, when superlattices without P-doped SiO2 were annealed at 800C.

S.W.Ryu, B.D.Choe, W.G.Jeong: Applied Physics Letters, 1997, 71[12], 1670-2