Raman Scattering Measurements and Analyses of ZnO Thin Films Grown on Sapphire Substrates by Metalorganic Chemical Vapor Deposition
Primary Investigator (PI) Name
Benjamin Klein
Department
Electrical Engineering
Abstract
The Raman Scattering (RS) characterization technique was used to examine a series of ZnO thin films, grown on sapphire substrates using metalorganic chemical vapor deposition (MOCVD). In the current study, thin films of ZnO were grown in a custom-built Low-Pressure Rotating Disk MOCVD Reactor. The growth temperature ranged from 200 to 1000°C, and the growth pressure ranged from 5-80 Torr. A series of ZnO thin films with different thicknesses (10-230 nm) were grown on c-plane sapphire substrates to study the dynamics of ZnO growth. The samples were prepared with a constant O2 flow rate of 8348 mmol/min. Raman spectra revealed peaks at 99 cm-1 and 437 cm-1, corresponding to the ZnO crystallinity characteristics of E2 (low) and E2 (high), respectively. The Raman features from the sapphire substrate were present in the specimen with revealed peaks at various other locations, including a strong peak at 416 cm-1. More measurements and analyses of other ZnO epi-films were obtained with similar results. The high crystalline quality of these ZnO materials was confirmed by optical characterization measurements.
Disciplines
Electrical and Computer Engineering
Raman Scattering Measurements and Analyses of ZnO Thin Films Grown on Sapphire Substrates by Metalorganic Chemical Vapor Deposition
The Raman Scattering (RS) characterization technique was used to examine a series of ZnO thin films, grown on sapphire substrates using metalorganic chemical vapor deposition (MOCVD). In the current study, thin films of ZnO were grown in a custom-built Low-Pressure Rotating Disk MOCVD Reactor. The growth temperature ranged from 200 to 1000°C, and the growth pressure ranged from 5-80 Torr. A series of ZnO thin films with different thicknesses (10-230 nm) were grown on c-plane sapphire substrates to study the dynamics of ZnO growth. The samples were prepared with a constant O2 flow rate of 8348 mmol/min. Raman spectra revealed peaks at 99 cm-1 and 437 cm-1, corresponding to the ZnO crystallinity characteristics of E2 (low) and E2 (high), respectively. The Raman features from the sapphire substrate were present in the specimen with revealed peaks at various other locations, including a strong peak at 416 cm-1. More measurements and analyses of other ZnO epi-films were obtained with similar results. The high crystalline quality of these ZnO materials was confirmed by optical characterization measurements.