## 2 Experimental Details  
The closed-field unbalanced magnetron sputtering system MSIP-016 with Ti, Al, and Mo targets was used for the experiments, as shown in Figure 3. SiO\({}_{2}\) and monocrystalline  
Figure 2: Schematic diagram of the setup of the plasma emission monitor (PEM)-controlled dual-gas reactive direct current magnetron sputtering (_dc_MS) system [8].  
silicon substrates were used for deposition. TiMoAlON film on SiO\({}_{2}\) substrate was used for the transmittance and reflectance test and the film on monocrystalline silicon substrate was used for elements and phase composition analysis. The reactive magnetron sputtering was controlled with the modified PEM controller, as mentioned before [8]. The substrate bias voltage was \(-45\) V and the main axle rotating speed of the samples' holder was 5 rpm. N\({}_{2}\) was supplied by the PEM controller and O\({}_{2}\) was supplied by MPC. A Ti atomic emission spectrum line intensity of 501 nm was monitored by PEM to control the N\({}_{2}\) supply.  
Before depositing, the samples were chemically cleaned by ultrasonic in acetone and absolute alcohol solution for ten minutes, respectively. The vacuum chamber was pumped down to a base pressure of \(4.0\times 10^{-3}\) Pa, and then the targets were cleaned in situ by argon ion bombardment for 15 min, wherein a DC bias of \(-400\) V was applied. The detailed preparation parameters are described in Table 1. In addition, it is an arduous task to deposit Al\({}_{2}\)O\({}_{3}\) film using DC reactive magnetron sputtering, so the processing parameters of preparing stoichiometric Al\({}_{2}\)O\({}_{3}\) must be obtained in advance by the PEM-monitored plasma emission spectrum intensity of Al. Simultaneously, the vacuum chamber was inflated with oxygen, the flow rate of which is gradually and slowly increased until the Al target is 'poisoned', and it reaches the maximum current of the Al target. The deposited films were baked at 500 \({}^{\circ}\)C in atmosphere for 8 h to investigate their thermal stability. A JSM-6700F field emission scanning electron microscope was used for cross-section morphology observation. Oxford energy disperse spectroscopy was used for composition analyses. A Shimadzu X-ray diffractometer was used to analyze phase structures, the scanning model of which is grazing incidence, and the grazing incident angle was 2\({}^{\circ}\), the scanning area was 20-80\({}^{\circ}\), and the scanning speed was 10\({}^{\circ}\)/min. A JEOL JEM-3010 transmission electron microscope was used for the fine-layer structure analysis. A Hitachi U-4100 spectrophotometer was used for transmissivity and reflectivity observation. The test value of reflectivity is the intensity ratio of reflected light and incident light. The absorptivity in the spectral region 300-2400 nm is an integral value. The integral value is approximated by subsection summation according to the following equation. During the calculation, the tested spectrum is equally divided into 50 sections.  
\[\rho_{\rm s}=\sum_{i=1}^{n}\rho_{s\lambda_{i}}E_{s}(\lambda_{i})\Delta\lambda_{ i}/\sum_{i=1}^{n}E_{s}(\lambda_{i})\Delta\lambda_{i}\]  
where, \(\rho_{\rm s}\) is the reflectivity in the tested spectrum range, \(\rho_{s\lambda i}\) is the tested reflectivity value when light wavelength is \(\lambda_{i}\), and \(E_{s}(\lambda_{i})\) is the light intensity when the light wavelength is \(\lambda_{i}\). A modified Fourier transform infrared spectrometer was used for emissivity measurement. The wavelength domain for the emissivity was 5-20 \(\upmu\)m.  
Figure 3: Layout of MSIP-016 sputtering chamber.