The origin of misfit dislocations in appreciably relaxed low-misfit strained-layers was considered. The characteristics of strain relief due to heterogeneous dislocation nucleation at particles, dislocation nucleation at the free surface of the layer, and multiplication mechanisms were considered and compared with observed relaxation behaviors. It was proposed that dislocation multiplication was consistent with a wide range of experimental results. The observation that 60º and edge dislocations were often seen lying above, but parallel to, the interface in sufficiently relaxed layers prompted a study of the 4 possible multiplication mechanisms that they could undergo in 32 of the theoretically available choices (table 7). It was shown that 25% of the reactions between 60º dislocations could lead to a pair of spiral dislocation sources, and that a single spiral source which operated only once could form at the end of edge dislocations.
Dislocation Multiplication Mechanisms in Low-Misfit Strained Epitaxial Layers. R.Beanland: Journal of Applied Physics, 1995, 77[12], 6217-22
Table 7
Possible Reactions between Glissile Threading Dislocations
and Internal 60º Dislocations
Burgers VectorT | Glide PlaneT | Burgers VectorI | Glide PlaneI | Line DirectionI | Reaction? |
½[101] | (¯111) | ½[101] | (¯111) | [110] | N |
½[101] | (¯111) | ½[101] | (¯1¯11) | [¯110] | Y |
½[101] | (¯111) | ½[¯101] | (1¯11) | [¯1¯10] | N |
½[101] | (¯111) | ½[¯101] | (111) | [1¯10] | Y |
½[101] | (¯111) | ½[011] | (1¯11) | [¯1¯10] | N |
½[101] | (¯111) | ½[011] | (¯1¯11) | [1¯10] | Y |
½[101] | (¯111) | ½[0¯11] | (¯111) | [110] | N |
½[101] | (¯111) | ½[0¯11] | (111) | [¯110] | Y |
½[101] | (¯1¯11) | ½[101] | (¯111) | [110] | Y |
½[101] | (¯1¯11) | ½[101] | (¯1¯11) | [¯110] | N |
½[101] | (¯1¯11) | ½[¯101] | (1¯11) | [¯1¯10] | Y |
½[101] | (¯1¯11) | ½[¯101] | (111) | [1¯10] | N |
½[101] | (¯1¯11) | ½[011] | (1¯11) | [¯1¯10] | Y |
½[101] | (¯1¯11) | ½[011] | (¯1¯11) | [1¯10] | N |
½[101] | (¯1¯11) | ½[0¯11] | (¯111) | [110] | Y |
½[101] | (¯1¯11) | ½[0¯11] | (111) | [¯110] | N |
½[¯101] | (1¯11) | ½[101] | (¯111) | [110] | N |
½[¯101] | (1¯11) | ½[101] | (¯1¯11) | [¯110] | Y |
½[¯101] | (1¯11) | ½[¯101] | (1¯11) | [¯1¯10] | N |
½[¯101] | (1¯11) | ½[¯101] | (111) | [1¯10] | Y |
½[¯101] | (1¯11) | ½[011] | (1¯11) | [¯1¯10] | N |
½[¯101] | (1¯11) | ½[011] | (¯1¯11) | [1¯10] | Y |
½[¯101] | (1¯11) | ½[0¯11] | (¯111) | [110] | N |
½[¯101] | (1¯11) | ½[0¯11] | (111) | [¯110] | Y |
½[¯101] | (111) | ½[101] | (¯111) | [110] | Y |
½[¯101] | (111) | ½[101] | (¯1¯11) | [¯110] | N |
½[¯101] | (111) | ½[¯101] | (1¯11) | [¯1¯10] | Y |
½[¯101] | (111) | ½[¯101] | (111) | [1¯10] | N |
½[¯101] | (111) | ½[011] | (1¯11) | [¯1¯10] | Y |
½[¯101] | (111) | ½[011] | (¯1¯11) | [1¯10] | N |
½[¯101] | (111) | ½[0¯11] | (¯111) | [110] | Y |
½[¯101] | (111) | ½[0¯11] | (111) | [¯110] | N |
½[011] | (1¯11) | ½[101] | (¯111) | [110] | N |
½[011] | (1¯11) | ½[101] | (¯1¯11) | [¯110] | Y |
½[011] | (1¯11) | ½[¯101] | (1¯11) | [¯1¯10] | N |
½[011] | (1¯11) | ½[¯101] | (111) | [1¯10] | Y |
½[011] | (1¯11) | ½[011] | (1¯11) | [¯1¯10] | N |
½[011] | (1¯11) | ½[011] | (¯1¯11) | [1¯10] | Y |
½[011] | (1¯11) | ½[0¯11] | (¯111) | [110] | N |
½[011] | (1¯11) | ½[0¯11] | (111) | [¯110] | Y |
½[011] | (¯1¯11) | ½[101] | (¯111) | [110] | Y |
½[011] | (¯1¯11) | ½[101] | (¯1¯11) | [¯110] | N |
½[011] | (¯1¯11) | ½[¯101] | (1¯11) | [¯1¯10] | Y |
½[011] | (¯1¯11) | ½[¯101] | (111) | [1¯10] | N |
½[011] | (¯1¯11) | ½[011] | (1¯11) | [¯1¯10] | Y |
½[011] | (¯1¯11) | ½[011] | (¯1¯11) | [1¯10] | N |
½[011] | (¯1¯11) | ½[0¯11] | (¯111) | [110] | Y |
½[011] | (¯1¯11) | ½[0¯11] | (111) | [¯110] | N |
½[0¯11] | (¯111) | ½[101] | (¯111) | [110] | N |
½[0¯11] | (¯111) | ½[101] | (¯1¯11) | [¯110] | Y |
½[0¯11] | (¯111) | ½[¯101] | (1¯11) | [¯1¯10] | N |
½[0¯11] | (¯111) | ½[¯101] | (111) | [1¯10] | Y |
½[0¯11] | (¯111) | ½[011] | (1¯11) | [¯1¯10] | N |
½[0¯11] | (¯111) | ½[011] | (¯1¯11) | [1¯10] | Y |
½[0¯11] | (¯111) | ½[0¯11] | (¯111) | [110] | N |
½[0¯11] | (¯111) | ½[0¯11] | (111) | [¯110] | Y |
½[0¯11] | (111) | ½[101] | (¯111) | [110] | Y |
½[0¯11] | (111) | ½[101] | (¯1¯11) | [¯110] | N |
½[0¯11] | (111) | ½[¯101] | (1¯11) | [¯1¯10] | Y |
½[0¯11] | (111) | ½[¯101] | (111) | [1¯10] | N |
½[0¯11] | (111) | ½[011] | (1¯11) | [¯1¯10] | Y |
½[0¯11] | (111) | ½[011] | (¯1¯11) | [1¯10] | N |
½[0¯11] | (111) | ½[0¯11] | (¯111) | [110] | Y |
½[0¯11] | (111) | ½[0¯11] | (111) | [¯110] | N |
T: threading dislocation, I: internal dislocation