Title of article :
Optimising uniformity of InAs/(InGaAs)/GaAs quantum
dots grown by metal organic vapor phase epitaxy
Author/Authors :
Linda Ho¨glund، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2006
Abstract :
A route towards optimisation of uniformity and density of InAs/(InGaAs)/GaAs quantum dots grown by metal organic vapor phase epitaxy
(MOVPE) through successive variations of the growth parameters is reported. It is demonstrated that a key parameter in obtaining a high density of
quantum dots is the V/III ratio, a fact which was shown to be valid when either AsH3 (arsine) or tertiary-butyl-arsine (TBA) were used as group V
precursors. Once the optimum V/III ratio was found, the size distribution was further improved by adjusting the nominal thickness of deposited
InAs material, resulting in an optimum thickness of 1.8 monolayers of InAs in our case. The number of coalesced dots was minimised by adjusting
the growth interruption time to approximately 30 s. Further, the uniformity was improved by increasing the growth temperature from 485 8C to
520 8C. By combining these optimised parameters, i.e. a growth temperature of 520 8C, 1.8 monolayers InAs thickness, 30 s growth stop time and
TBA as group V precursor, a full-width-half-maximum (FWHM) of the low temperature luminescence band of 40 meV was achieved, indicating a
narrow dot size distribution
Keywords :
epitaxy , MOVPE , Quantum dot , InAs/GaAs , TBA , growth
Journal title :
Applied Surface Science
Journal title :
Applied Surface Science