Structural and Optical Studies of GaN Grown on Si by MOCVD
Disciplines
Electrical and Computer Engineering
Abstract (300 words maximum)
GaN films grown on silicon have been explored as a wide bandgap semiconductor material in the past two decades. The X-ray diffraction (XRD) technique is used for the analysis of semiconductor crystal structures, whereas the Raman experiment allows us to understand the composition and homogeneity of the epitaxial semiconductor sample. In this study, four GaN thin films grown on Silicon substrates via metalorganic chemical vapor deposition (MOCVD) were examined. For two samples, we performed XRD measurements, while for the other two, we conducted Raman scattering measurements. In the XRD experiments, the wide scan and fine scan step sizes are taken as 0.1° and 0.005°, respectively. The XRD graph of the first sample indicates that the Si first order (002) is at ~28° and the second order (004) is at ~90°, and a weak peak at about 35° indicates the peak of GaN (0002). For the second sample of the XRD experiment, the Si (002) and (004) substrate peaks are oriented also at 28° and 90°, while the GaN (0002), (0004), and (0006) peaks are observed clearly. The first order of the GaN peak is about 34.6°, the second order is approximately 73°, and the third order is around 127°. We examined the Raman scattering under a microscope at room temperature on two samples with 5%, 1%, and 0.5% excitation laser powers, respectively. The first Raman experiment indicated peaks at 520 cm-1 for Si and 565 cm-1 for GaN crystallinity characteristics E2 (High) and A1 (LO), respectively. The Si, GaN E2 (High), and GaN A1 (LO) Raman spectra for the second Raman experiment exhibited peaks at 520 cm-1, 567 cm-1, and 734 cm-1, respectively. With these experiments, our study provides evidence via structural and optical characterization of the exceptional crystalline purity of these GaN on Si samples.
Academic department under which the project should be listed
SPCEET - Electrical and Computer Engineering
Primary Investigator (PI) Name
Benjamin Klein
Additional Faculty
Ian Ferguson, Electrical and Computer Engineering, ifergus3@kennesaw.edu
Structural and Optical Studies of GaN Grown on Si by MOCVD
GaN films grown on silicon have been explored as a wide bandgap semiconductor material in the past two decades. The X-ray diffraction (XRD) technique is used for the analysis of semiconductor crystal structures, whereas the Raman experiment allows us to understand the composition and homogeneity of the epitaxial semiconductor sample. In this study, four GaN thin films grown on Silicon substrates via metalorganic chemical vapor deposition (MOCVD) were examined. For two samples, we performed XRD measurements, while for the other two, we conducted Raman scattering measurements. In the XRD experiments, the wide scan and fine scan step sizes are taken as 0.1° and 0.005°, respectively. The XRD graph of the first sample indicates that the Si first order (002) is at ~28° and the second order (004) is at ~90°, and a weak peak at about 35° indicates the peak of GaN (0002). For the second sample of the XRD experiment, the Si (002) and (004) substrate peaks are oriented also at 28° and 90°, while the GaN (0002), (0004), and (0006) peaks are observed clearly. The first order of the GaN peak is about 34.6°, the second order is approximately 73°, and the third order is around 127°. We examined the Raman scattering under a microscope at room temperature on two samples with 5%, 1%, and 0.5% excitation laser powers, respectively. The first Raman experiment indicated peaks at 520 cm-1 for Si and 565 cm-1 for GaN crystallinity characteristics E2 (High) and A1 (LO), respectively. The Si, GaN E2 (High), and GaN A1 (LO) Raman spectra for the second Raman experiment exhibited peaks at 520 cm-1, 567 cm-1, and 734 cm-1, respectively. With these experiments, our study provides evidence via structural and optical characterization of the exceptional crystalline purity of these GaN on Si samples.