Design and Fabrication of Ultraviolet-Selective Microsensor Using Standard Silicon Process
| Autor: | Chih-Hung Fang, 方智弘 |
|---|---|
| Rok vydání: | 2016 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 104 This study designs and implements an ultraviolet-selective micro sensors in standard complementary metal-oxide semiconductor micro electro mechanical systems (CMOS-MEMS) 0.18 μm process of Taiwan Semiconductor Manufacturing Company (TSMC). The active region of p-n junction is heavy p-type doping and N-well. The electron–hole pair is generated when photons are absorbed in the photodiode. The photon can provide enough energy for material. It refers to the energy difference between the top of the valence band and the bottom of the conduction band. Electrons are able to jump from one band to another. The semiconductor has a small band gap but non-zero. Energy gap of general semiconductor material is about 1-3 eV. The electric field could generate in p-n junction. The electron–hole pair would be move by electric field, and produced photocurrent. An octagonal shape was adopted to reduce the electrical field at the corners, and to avoid corner breakdown. The chip uses a buffer etch oxide solution to remove the sacrificial layer of silicon dioxide. This way can enhance the ultraviolet sensor sensitivity. The device operates in avalanche mode. Photocurrent is gained by impact ionization inside the structure, which enhances responsivity. This work develops an ultraviolet-selective micro sensor with low dark current and good sensitivity. The experimental results showed that the Ultraviolet sensor had a breakdown voltage of 9.5 V. The photodiode had a maximal current of 54.8 μA with a reverse voltage 9.4 V at wavelength 400 nm. The device has the advantages of small size, low power consumption and low cost. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|