| Summary: | 碩士 === 國立臺灣科技大學 === 化學工程系 === 104 === The aim of this study is to explore a suitable LPCVD reaction system that can form gallium doped zinc oxide (GZO) film as an alternative to indium tin oxide (ITO) functioned as the transparent conductive layer for blue light LEDS. To have GZO films that can diffuse light well in in wavelength of 455~475 nm for a better light extraction effect for the devices, films were synthesized intentionally at LPCVD reaction temperatures lower than 200ºC by which GZO films with surface roughness can be obtained. Emphasis is placed upon improving the electric conductivity of the low temperature synthesized films by using various annealing methods.
Firstly of all, we found the GZO films annealed in a forming gas consisted of a flow stream of [H2]/[N2] =5/50 sccm under 400ºC exhibited an improvement of 50% in carrier concentration. Nevertheless, the mobility dropped down dramatically. In contrast, the films annealed by a rapid thermal processing using a temperature ramping rate of 10ºC/s up to 400ºC and continuing to only a short period of 2 min, not only increased the carrier concentration but also preserved the mobility, resulting in a decrease of film resistivity from 5 × 10-3 Ω·cm to 3 × 10-3 Ω·cm.
|
|---|
