Hydrogen and Humidity Sensors from Si Nanodevices with Selective Modifications via Nanoscale Joule Heating
|關鍵字:||氫氣感測器;焦耳熱;濕度感測器;白金;氧化鋅;Hydrogen sensor;Joule Heating;Humidity sensor;Platinum;Zinc oxide|
|摘要:||本研究運用焦耳熱輔助原子層化學沉積系統 (Atomic Layer Chemical Vapor
Deposition, ALCVD) 選擇性沉積鉑金屬 (Platinum) 於元件上做為氫氣感測器使
COMSOL 多重物理偶合模擬 self-heating 時表面溫度分布，與供給不同電壓下鉑
金屬的沉積情形相互驗證。將製備好的元件置於 PDMS 製作的小腔體中進行氫
In this study, we report the experimental results of selective deposition of Platinum via localized joule heating assisted atomic layer deposition on nanodevices as real-time hydrogen sensors. The active channels of nanobelt devices were consisted of n+/n-/n+ structure, and localized joule heating was induced at local high resistance n- region. The surface temperature was estimated by COMSOL simulations for different biases. AFM was used to investigate the morphology of Pt deposition at various conditions. Prepared devices were settled in a small chamber made by PDMS to perform the hydrogen detection. The effect of different Pt morphology was also compared on hydrogen sensing characteristics so that the deposition conditions were optimized simultaneously. Furthermore, several self-heating voltages were applied to accelerate response time of hydrogen sensing. The detection limit under atmosphere is about 1.5 ppm. In addition, selective ZnO modifications were achieved via localized PMMA ablation with Joule heating as humidity sensors. The developed ZnO-based humidity sensors were prepared as reference sensors in order to compensate humidity interference to H2 sensors.
|Appears in Collections:||Thesis|