Study on the Noise Behaviors of a-IGZO TFTs under Bias and Illumination

• Main Authors: Hsieh, Chung-Lun, 謝忠倫
• Other Authors: Tai, Ya-Hsiang
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/11006239710119723044

碩士 === 國立交通大學 === 顯示科技研究所 === 102 === In this thesis, we investigate the response of noise for the a-IGZO TFTs to the light intensity. The measured spectrum of device is calculated by integration to reduce the error caused by the spectrum fluctuation. Compared with the case of non-illumination, the noise level increases, which make us interested in the study of noise behavior with respect to the light intensity. In the experiment of changing light intensity, we find that the induced noise with respect to the same drain current (ID) gets more with illumination even though the ID corresponded gate voltage (VG) can be different. With fixed intensity, the noise induced at the same ID is not changed regardless of the illumination history. After the analysis, the noise is thought to be caused by the mobility fluctuation which model is proposed by F. N. Hooge. There is a close relationship between the scattering effect and mobility fluctuation. By the calculation based on this model, we discover that when the light intensity rises, the Hooge’s parameter is larger. We speculate that oxygen vacancy affects the scattering and leads to the noise increasing with illumination. Through this study, we can better understand the noise generation situation with illumination. It is expected to be helpful for the future applications in design of pixel light sensing circuit to achieve better imaging quality.