| Summary: | 碩士 === 國立交通大學 === 電子物理系 === 86 ===
We has successfully grown the GaN film using metalorganic chemical phase deposition method. From the Van der Pauw and Hall measurement, it is found that the GaN film quality is very sensitive to the growth conditions, such as buffer layer thickness, ramping rate of buffer layer thermal annealing, growth temperature, growth rate, nitridation and V/Ⅲ ratio. Nevertheless, a device quality of GaN film has been obtained. The corresponding carrier mobility as high as 300 cm2/Vs and carrier concentration is lower than 1017 cm-3.
Moreover, a schottky diode coated by Pd on n-type GaN was fabricated. The measured ideality factor is of 1.115 and the barrier heights as determined by I-V, I-V-T, C-V measurements are -0.9 eV, 0.91 eV and 1.23 eV, respectively. These values indicate a good quality of our GaN film. In addition, we have found that the GaN films prepared by our group possess a majority-carrier trap located at 0.435 eV below conduction band. Since the trap contration and cross-section are rather low (5.64×1014 cm-3 and 4.618×10-18 cm-2 respectively), we believe this trap will not bring any affections on the performance of GaN devices.
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