Growth and characterization of LPCVD Si quantum dots on insulators

Abstract

We present a complete study of Si nanocrystals growth by Chemical Vapor Deposition. Si NCs are grown using SiH 4 as precursor, on thermal SiO 2, deposited Si 3N 4 and Al 2O 3. We have studied the influence of the experimental parameters on Si-NCs formation. On SiO 2 and Al 2O 3, we have identified OH groups as nucleation sites 2. Hence, by controlling the OH density on the SiO 2 surface, we can monitor the Si-QDs density between 10 10 and 1.5 × 10 12/cm 2. To control the Si-QDs size, we have developed an original two steps process which separates the nucleation and the growth of Si-QDs. In the first step, the density is fixed by exposing the treated SiO 2 surface to SiH 4 precursor. In the second step, the Si-QDs growth is obtained only on previously formed Si nuclei by using a selective precursor, namely SiH 2Cl 2.