The dislocation generation mechanism of In/sub x/Ga/sub 1-x/As epilayers (0.32/spl les/2/spl les/1) grown on InP substrates by molecular-beam epitaxy

The dislocation generation mechanism of the In/sub x/Ga/sub 1-x/As epilayers grown on InP substrates with 0.32/spl les/2/spl les/1 were investigated. It was found that the growth mode is not only dependent on the lattice mismatch, the abundance of Ga atoms and the degree of cation disorder in the alloy composition also play important roles. In the negative mismatched range even with a medium lattice mismatch, InGaAs alloys with high degree of cation disorder and containing more Ga atoms (x=0.32-0.37) trigger island growth and introduce high-density dislocations.<
>