Reducing InGaN dimensions is a effective way to increase the work-efficiency of GaN-based light emitting devices (LED). This paper describes our research on the growths of InGaN quantum dots (QDs) and on the analyses of their properties. Instead of the usual Stranski Krastannow growth or surfactant induction

our method consists of three steps: an introduction of second buffer layer on a GaN/Al

2

O

3

substrate

a passivation process for the buffer layer surface at a low temperature

a InGaN QDs fabrication by metal organic chemical vapor deposition (MOCVD). Based on our method

InGaN QDs with high density could be achieved

shown in this paper

we contribute these QDs formation to non-uniform surface-stress at the buffer layer surface. These InGaN QDs have been studied by atomic force microscopy (AFM)

transmission electron microscopy (TEM) and photoluminescence (PL) techniques for their microstructure and optical properties respectively. It is shown that InGaN QDs distributed with the density of 10

11

cm

-2

and appeared as cones with about 30nm diameter and 25nm height. The intensity of PL spectrum of InGaN QDs at room temperature is much higher than that of the normal InGaN film grown with the same growth condition

which may be used for making GaN based light emitting devices with high efficiency.