Resistivity Control in Unintentionally Doped GaN Films Grown on Si (111) Substrates by MOCVD

Abstract:

Unintentionally doped GaN were grown on Si (111) substrates by metal organic chemical vapor deposition (MOCVD). The high-resolution X-ray diffraction (HRXRD) and Lehighton contactless sheet resistance measuring systems were employed to characterize the quality and sheet resistance (R_s) of GaN epilayer. The threading dislocation density (TDD) was estimated by calculating the full width at half maximum (FWHM) of GaN (0002) and (10-12) diffractions measured by HRXRD. The relationship between R_s and TDD in GaN epilayer was investigated. The influence of growth conditions of bottom GaN initial layer including carrier gas category (H₂ or N₂), growth temperatures, and growth pressures on the quality or resistivity of top GaN epilayer was discussed and analyzed. As a result, the improved resistivity was achieved in top GaN epilayer with low TDD by using H2 carrier, low growth temperature of 1050°C, and high growth pressure of 400mbar during the growth of bottom GaN initial layer.

• Periodical: Advanced Materials Research (Volumes 415-417)
• Pages: 1959-1963
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.415-417.1959
• Online since: December 2011
• Authors: Yong Wang, Nai Sen Yu, Ming Li, Kei May Lau
• Keywords: High Resistivity, MOCVD, Si Substrate, TDD, Unintentionally Doped GaN

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