Defects and morphologies in In0.8Ga0.2As/InAlAs/InP(001) for high electron-mobility transistors

Defects and morphologies are presented in this paper as revealed with trans mission electron microscope (TEM) in the In(0.8)G(0.2)As/InAlAs heterostruc ture on InP(001) for high-electron-mobility transistors application. Most o f the misfit dislocation lines are 60 degrees type and they deviate < 110 > at some angles to either side according to their Burges vectors. The misfi t dislocation lines deviating [-110] are divided into two types according t o whether their edge component b(eg) of Burges vectors in [001] pointing up or down. If b(eg) points up in the growth direction, there is the local pe riodical strain modulation along the dislocation line. In addition, the per iodical modulation in height along [-110] on the In(0.8)G(0.2)As surface is observed, this surface morphology is not associated with the relaxation of mismatch strain.