Measurement and Analysis of Surface Temperature Gradients on Magnetron Sputtered Thin Film Growth Studied Using NiCr/NiSi Thin Film Thermocouples

In the general analysis of thin-film growth processes, it is often assumed that the temperature of the film growth surface is the same as the temperature of the film growth substrate. However, a temperature gradient exists between the film growth surface and film growth substrate. Using the growth surface of TiO₂ thin films as an example, the temperature gradient of the film growth surface is tested and analyzed. A NiCr/NiSi thin-film thermocouple is fabricated using the direct-current pulse magnetron sputtering method. A three-layer NiCr/NiSi thin-film thermocouple temperature measurement system is established to measure the temperature gradient of the film growth surface. The growth surface temperature and substrate temperature of the TiO₂ thin films are measured. For a sputtering power density of 0.83 W cm^- ², the temperature difference between the first and second layers is 104.79 °C, while the temperature difference between the second and third layers is 39.92 °C. A standard K-type thermocouple is used to measure the substrate temperature, which is recorded to be 132.05 °C, consistent with common measurements of substrate temperature. The heat conduction on the film growth surface in the vacuum chamber is examined and a model for the temperature measurement device during film growth is constructed.