Rapid Thermal Processing with Real-Time Measurement Using Type-K Thermocouple

High-temperature thermal treatments are necessary to improve the structural stability of sensor and chemical reactivity between a detecting gas and a sensor. These processes require accurate ratios between the gas-sensing materials and the metal-catalyst materials, after the high-temperature vacuum thermal treatment, to improve electrical stability, reproducibility, and reliability. Therefore, exact temperature control is necessary in the process. In this study, direct-indirect methods of real-time measurement and control of substrate temperature were developed to resolve the issues that arise when using either method (direct or indirect) alone. Using this method, it is possible to measure the exact substrate temperature of the semiconductor gas sensor. If the temperature of the substrate is not controlled during rapid thermal processing (RTP), the evaporation of nanostructures can occur. However, if the temperature of the substrate can be controlled exactly using the direct-indirect temperature-control methods, an accurate rate of temperature can be adjusted. According to the results of the energy dispersive X-ray spectrometry conducted on samples where thin-film Ag (a metal catalyst) with SnO2 nanostructures were formed using high-vacuum metalizing, the concentration of Ag was shown to be 4.71% after 5 min of processing. The results of EDS conducted on the samples processed by annealing at 300 degrees C for 5 min using the real RTP confirmed that the concentration of Ag was shown to be 6.35% after 5 min of processing. This means that the detecting materials of SnO2 and the ratio of Ag catalyst materials were controlled with a ratio within 5%.