Carrier Density of Lateral Epitaxial Overgrown GaN Using Scanning Confocal Raman Microscopy
01 January 2001
GaN thin films, grown by the lateral epitaxial overgrowth (LEO) method are studied by scanning confocal Raman microscopsuring changes in longitudinal optical phonon-plasmon frequencies and using a standard harmonic oscillator dielectric function detailed images of carrier denisty could be formed. Carrier concentrations are extremely high (~10(20th) cm(-3)) immediately aboabove Si0x mask layers and decrease abrubtly when the SiOx masks are n ot directly exposed to the growth surface, implying that SiOx masks are the source of dopants. Images of integrated E1 longitudinal optical phonon intensities could be compared with free carrier images and showed a clear anti-correlation throughout the LEO structure.