Experiments were performed on 2 multiple quantum well heterostructures which each had 4 quantum wells with In concentrations (in order from the surface) of 5, 15, 20 and 10%. The various In concentrations in the well were placed in this order so that any effects, such as enhanced diffusion caused by the surface or substrate, would not be confused with a strain effect. Similarly, the structures were grown with various barrier thicknesses in order to check for any depth effects which may be caused by the in-diffusion of vacancies from the surface. No effect of strain or depth upon diffusion (table 4) was observed.
Effect of strain on the interdiffusion of InGaAs/GaAs heterostructures W.P.Gillin: Journal of Applied Physics, 1999, 85[2], 790-3
Table 4
Interdiffusion in GaInAs/GaAs Quantum Wells
Temperature (C) | Well | D (cm2/s) |
900 | Ga0.95In0.05As | 4.7 x 10-17 |
900 | Ga0.9In0.1As | 3.0 x 10-17 |
900 | Ga0.85In0.15As | 4.0 x 10-17 |
900 | Ga0.8In0.2As | 4.2 x 10-17 |
950 | Ga0.95In0.05As | 1.2 x 10-16 |
950 | Ga0.9In0.1As | 1.4 x 10-16 |
950 | Ga0.85In0.15As | 2.0 x 10-16 |
950 | Ga0.8In0.2As | 2.2 x 10-16 |
1000 | Ga0.95In0.05As | 6.2 x 10-16 |
1000 | Ga0.9In0.1As | 5.0 x 10-16 |
1000 | Ga0.85In0.15As | 7.6 x 10-16 |
1000 | Ga0.8In0.2As | 7.4 x 10-16 |
1050 | Ga0.95In0.05As | 5.3 x 10-15 |
1050 | Ga0.9In0.1As | 5.8 x 10-15 |
1050 | Ga0.85In0.15As | 7.0 x 10-15 |
1050 | Ga0.8In0.2As | 8.2 x 10-15 |