“…Excess Al and Ga atoms, as well as residual oxygen atoms, can agglomerate in the dissolution pits, and they might act as the catalyst for the growth of twin boundaries [23], similar to boron atoms on a silicon substrate [24]. It is considered that the orientation of twin boundaries distributes unisotropically due to the difference of the growth rates on different atomic planes [22], and the growth rate of f1 1 1g A differs from that of f1 1 1g B for AlGaAs [10]. Also, the density of twin boundaries on f1 1 1g B is higher than that on f1 1 1g A for growth conditions which give the Volmer-Weber mode island deposits [25].…”