ABSTRACT
Nanometer-scale selective area growth of ZnS and ZnSe on GaAs substrates covered with a carbon mask was investigated. The carbon-based mask was deposited by electron-beam irradiation and patterned by atomic force microscope. ZnS and ZnSe were grown by metalorganic molecular-beam epitaxy (MOMBE) at substrate temperature from 350°C to 390°C. In the case of patterns with size of several hundred of nanometers a good selectivity and uniformity of the grown structures were observed. However, when the opening size was decreased to less than —100 nm, inhomogeneity of the grown structures appeared and could be identified to originate from the poor nucleation. In order to solve this issue the conditions for enhancing the nucleation were studied. The replacement of the As-Zn pair with Ga-S or Ga-Se at the heterointerface proved to enhance the nucleation probability. As a result the uniformity of the grown nanostructures was much improved.
