Summary: | 碩士 === 國立臺灣科技大學 === 機械工程系 === 103 === The purpose of this study is to design a ceramic thin film to substitute the polymer resist used in LIGA process. The ceramic thin films must have the following characteristics:
Resistivity – To prevent electroformed metal deposition on the die.
Mechanical properties – To prevent the thin film ceramic from rupturing by the external forces
Fracture toughness – To prevent the thin film ceramic from rupturing in bending step.
Substrate adhesion – To prevent the separation of ceramic thin films and substrate.
Corrosion resistance – To prevent the thin film ceramic from corrosion, during the etching process.
Sputtering technique was used to prepare an aluminum nitride-zirconium nitride multilayer thin film. In order to achieve the thin film characteristics as stated above, we incorporated the high mechanical properties of zirconium nitride and high resistivity of aluminum nitride. The nitrogen flow and metal interlayer thickness are the parameters taken for the experimental study, and confirmation tests are carried out by measuring thin film properties of aluminum nitride and zirconium nitride respectively.
A DC reactive magnetron sputtering is used to prepare an aluminum nitride and zirconium nitride thin film, and changing the experimental parameters:
(1) Keeping the flow rate of argon constant (10 sccm) and varying the flow rate of nitrogen (0, 2.5, 5, 7.5, 10, 12.5sccm)
(2) Keeping the total sputtering time constant and varying the metal interlayer (5, 10, 15, 20 minutes) and nitride films sputtering time.
The results showed that 2.5 sccm nitrogen flow of zirconium nitride thin films has the highest Young's modulus (241.4GPa), micro-hardness (28GPa) and the fracture toughness (0.731 MPa√m). Aluminum nitride showed the highest resistivity (12058 Ω-cm), corrosion resistance (1.29×〖10〗^5 Ωcm2) when the nitrogen flow is at 10sccm. Both of zirconium nitride and aluminum nitride have the best substrate adhesion (HF1) with stainless steel.
In metal interlayer experiments, added metal interlayer will influence the thin film properties. The decrease of the thin film properties is different in fracture toughness. Adding an aluminum interlayer can improve the fracture toughness of aluminum nitride thin films.
From the experimental results, it showed that the amount of reaction gas (nitrogen) will significantly affect the thin film properties, substrate temperature can influence the crystallinity of the thin film and residual stress is also an important parameter to determine thin film characteristics.
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