SD-650MH High-Vacuum Magnetron Sputtering Titanium Coating – Technical Application Case Study

SD-650MH High-Vacuum Magnetron Sputtering Titanium Coating – Technical Application Case Study

In advanced manufacturing sectors such as semiconductors, battery materials, composite materials, and new materials research, copper is widely used for its excellent electrical and thermal conductivity. However, bare copper surfaces are prone to corrosion. To enhance the durability of copper components under harsh conditions, a protective coating is often applied in collaboration with our client, we developed optimized sputtering process parameters using the SD-650MH high-vacuum magnetron sputtering system to deposit a 3 μm-thick pure titanium coating on copper substrates. This significantly improved the corrosion resistance and coating–substrate adhesion. By introducing dynamic vacuum control and other innovative techniques, the process achieved both higher deposition rates and improved film quality, showcasing the SD-650MH system’s outstanding performance in advanced thin-film preparation.

The goal was to form an approximately 3 μm titanium thin film on copper workpieces via magnetron sputtering. This film thickness provides an effective corrosion barrier without significantly increasing the component’s weight while ensuring strong adhesion to the copper substrate. The introduction of a dynamic vacuum feedback control system optimizes argon pressure during deposition, enhancing both sputtering rates and process stability. In short, the process aimed to meet demanding performance requirements while improving deposition efficiency and uniformity.

Core Equipment and Features – SD-650MH High-Vacuum Magnetron Sputtering System

• High Vacuum Capability

  Equipped with a mechanical pump and turbomolecular pump, the system achieves an ultimate vacuum of ≤ 5 × 10⁻⁴ Pa. High-vacuum conditions minimize contamination, ensuring high film purity. Standard chamber configurations include a sputtering chamber, magnetron sputtering target, rotating substrate holder, pumping system, and gas flow controls, with optional accessories such as thickness monitors and heating stages.

  
  

• Dynamic Vacuum Feedback System

  The SD-650MH features an automatic vacuum feedback control that adjusts argon gas flow in real time to maintain a stable working pressure. This keeps pressure fluctuations within ±3% during deposition, eliminating the need for repeated manual valve adjustments and ensuring stable plasma discharge.

• DC Magnetron Sputtering Power Supply

  The system comes with a DC sputtering power supply (up to 1000 W). In this process, 1000 W DC was used for stable output, ideal for conductive materials such as titanium. Voltage and current stability ensure consistent discharge. For non-conductive targets, an RF power mode is available, expanding material compatibility.

• Additional Features

  Magnetic target design increases plasma density over the target surface, improving sputtering rates while reducing substrate heating. A water-cooling system controls substrate temperature to below 50 °C when needed. The rotating substrate holder improves coating uniformity, especially for large workpieces. In this process, a high-purity titanium target (99.99%) and high-purity argon gas (99.999%) were used.

Process Workflow

1.      Substrate PreparationCopper workpieces were ultrasonically cleaned in acetone and anhydrous ethanol (15 min each) to remove oils and oxides, then dried with high-purity nitrogen. Workpieces were mounted parallel to the titanium target, at an 80–100 mm spacing.

2.      Vacuum PumpingInitial pumping with a mechanical pump reduced pressure to ≤ 4 Pa, followed by turbomolecular pumping to reach ≤ 5 × 10⁻⁴ Pa.

3.      Plasma Ignition & Pre-SputteringArgon was introduced to 2 Pa (ignition pressure), and the DC power supply was set to 200 W. The initial purple-red plasma glow (Ar⁺ emission) corresponded to a sputtering rate of 0.5 Å/s. Pre-sputtering lasted 5 min with a shutter covering the substrate to clean the target surface.

4.     Dynamic Vacuum Adjustment & Titanium DepositionWith the shutter open, argon pressure was gradually reduced from 2 Pa to ~ 5 × 10⁻¹ Pa in 0.5 Pa steps, pausing 10 s at each step to monitor glow color and deposition rate. At ~ 0.5 Pa, the plasma glow shifted from purple-red to bright blue, indicating titanium-dominated sputtering, and the deposition rate rose to ~ 5.2 Å/s. Pressures below ~ 3 × 10⁻¹ Pa caused plasma instability and rate drops, so the optimal pressure was maintained at ~ 0.5 Pa. Substrate temperature was kept near room temperature, with water cooling activated if > 50 °C. Deposition time was ~ 90 min to achieve 3 μm thickness.

5.      Process CompletionAfter reaching target thickness, sputtering was stopped and argon flow shut off. The chamber was kept under vacuum for 10 min to allow cooling, preventing oxidation or cracking. Nitrogen was then introduced to atmospheric pressure before unloading the parts.

Key Process Highlights

• Dynamic Vacuum Optimization increased deposition rate from 0.5 Å/s to 5.2 Å/s while maintaining stability.

• Plasma Glow Monitoring provided a visual indicator for process stability—purple-red for argon-dominated cleaning, bright blue for titanium-rich stable deposition.

• Process Stability was enhanced by automatic feedback control, keeping vacuum fluctuations within ±3%.

Critical Parameters Summary

Quality Evaluation

• Thickness Measurement: Step profiler or XRF; ±3% deviation.

• Adhesion Test: Scratch test; critical load > 25 N.

• Uniformity: SEM cross-section analysis; thickness variation ≤ ±3%.

Application Scenarios

• Precision Electronics: RF connectors, microwave devices, PCB copper conductors—enhanced oxidation resistance and impedance control.

• Electrochemical Devices: Battery current collectors, electrolyzer anodes—improved corrosion resistance in harsh electrolytes.

• Marine Corrosion Protection: Copper alloy components in seawater—chloride corrosion resistance, extended service life.

Using the SD-650MH high-vacuum magnetron sputtering system with dynamic vacuum feedback and stable DC sputtering, we successfully deposited high-quality titanium films on copper substrates. The process delivers precise thickness control, excellent adhesion, and uniformity. This technology has broad application potential in semiconductors, energy storage, and corrosion protection, and serves as a proven reference for advanced thin-film engineering.