Alignment of InP Stranski–Krastanow dots by growth on patterned GaAs/GaInP surfaces

Stranski–Krastanow islands of InP nucleate in straight rows when deposited by metalorganic vapor phase epitaxy on linearly patterned GaInP/GaAs surfaces. The patterns were produced by overgrowth of lithographically defined W stripes 30° off from [110] on a GaAs(001) surface. Depending on the geometry of the grown GaAs/GaInP mesa stripes the islands were found to align either on top of the ridges, at the sidewall near to the mesa edge or at the bottom of the trenches. The highest density of almost equidistant coherent islands observed in some of the rows is in the order of 10 islands/μm, corresponding to a surface area density of 1010 InP islands/cm2. The maximum density of randomly distributed islands in the unpatterned area otherwise is only 2×109 islands/cm2. The results show a successful combination of overgrowth of conducting metal stripes and lateral geometrical positioning of dots in one in situ growth step.