Nucleation in the nanometer scale selective area growth of II-VI semiconductors

Nanometer-scale selective area growth of ZnS and ZnSe was investigated. The growth was performed by metalorganic molecular-beam epitaxy (MOMBE) on a c arbon-masked GaAs substrate at temperatures ranging from 350 degrees C to 3 90 degrees C. For pattern sizes larger than several hundred of nanometers, a good selectivity and uniformity of the frown structures were observed, bu t for mask opening sizes less than similar to 100nm, uniformity of the grow n structures was not satisfactory. This situation was identified as origina ting from the poor nucleation and to be intrinsic to the nanometer-scale se lective area growth. In order to resolve this issue, the conditions for enh ancing the nucleation were studied. The replacement of conventional As-Zn b onding with Ga-S or Ga-Se bonding at the heterointerface proved to be effec tive for enhancing the nucleation probability, and thus, the uniformity of the grown nanostructures, while preserving good selectivity.