Fabrication of Infrared Thermal Emitters with Spiral Shape Micro Metal Heater by CMOS Process
| Autor: | Shih-Hao Lai, 賴世豪 |
|---|---|
| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 Besides the industrial applications, far-infrared (FIR) thermal emitters are useful in medical applications, for example, to enhance blood circulation and accelerate wound healing. Reducing costs and mass production are the keys to make FIR emitters wide-spreading in various applications. This work aims to develop far-infrared thermal emitters with enhanced thermal uniformity and luminous efficiency. Fifteen components of different parameters are designed and fabricated for performance comparisons. The components are manufactured using the existing standard 0.18 µm CMOS process to achieve good process stability, low cost, and large-scale manufacturing goals. The heating wire is designed as spiral shape rather than the previous U-shape in order to have uniform temperature distribution. The metal layer is adopted as the heating material and it has a positive temperature coefficient of resistance. After applying a voltage to the metal layer, the temperature starts to rise and thus increases the electric resistance. It could suppress the input current and prevent the device overload and burnout when the temperature is high. Some of these designs require the MEMS process technology provided by the MPW service to etch hollows and remove the substrate under the heating wires. This is for providing thermal isolation to improve the heating efficiency. After measuring all the thermal emitters, the luminous efficiency is higher than the previous work. The optical spectra are above 8 µm of wavelength. The maximum luminous efficiency is 5.7×10-5 at a bias voltage of 5 V. The power density was 2.48 mW/cm2, and the surface temperature distribution is very uniform. Compare of different thermal emitters, we find that etched hollows can provide good thermal isolation. The devices with the same line width and material but smaller resistance values generate higher luminous efficiency at a fixed voltage. The devices with the same chip size but larger resistance values can tolerate a larger applied voltage. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
| Externí odkaz: |
|