The Process of Magnetron Sputtering TiN Films

The process of magnetron sputtering TiN films involves several steps, each requiring precise control and operation. Below is a detailed process flow:

1. Substrate Preparation

Cleaning:

• Ultrasonic      Cleaning: The substrate is      typically subjected to ultrasonic cleaning to remove surface contaminants      such as oil, dust, and other impurities. Cleaning solvents like ethanol,      acetone, or other suitable solvents can be used.

• Deionized      Water Rinse: After      cleaning, the substrate is rinsed with deionized water to remove any      residual cleaning solution.

• Drying: The substrate is dried, either by baking or      using nitrogen gas, to ensure no moisture remains on the surface.

Surface Treatment:

• Polishing: For substrates requiring a high level of      smoothness, mechanical or chemical polishing may be performed.

• Activation      Treatment: If necessary, plasma      cleaning can be used to activate the substrate surface.

2. Substrate Loading

Loading the Substrate:

• The cleaned      substrate is loaded onto the substrate holder of the coating equipment. It      is crucial to ensure that the substrate is securely fixed and evenly      distributed to ensure uniform coating.

3. Vacuum Chamber Evacuation

Primary Vacuum:

• The vacuum      pump (such as a mechanical pump) is started to evacuate the vacuum chamber      to a primary vacuum state (typically around 10^-2 Torr).

High Vacuum:

• The high      vacuum pump (such as a molecular pump or turbomolecular pump) is then      activated to further evacuate the chamber to a high vacuum state (usually      in the range of 10^-5 to 10^-7 Torr).

4. Gas Introduction and Sputter Cleaning

Introduction of Sputtering Gas:

• Inert gas      (such as argon, Ar) is introduced into the vacuum chamber, with a working      pressure typically in the range of 1-10 mTorr.

Substrate Sputter Cleaning:

• A negative      bias is applied to the substrate, causing sputter cleaning of the      substrate surface to remove any oxide layers and residual contaminants.

5. Magnetron Sputtering of TiN Film

Introduction of Reactive Gas:

• On the basis      of the argon gas, nitrogen gas (N2) is introduced as a reactive gas. The      flow ratio of the gases is controlled to achieve the desired      stoichiometry.

Start Sputtering Power:

• The magnetron      sputtering power supply is activated, applying either DC or RF power to      the Ti target to generate plasma.

Sputter Deposition of TiN:

• Titanium      atoms are sputtered from the target surface by argon ions and react with      nitrogen gas, forming a TiN film on the substrate surface. Sputtering      power, gas flow, and substrate temperature are adjusted to control the      deposition rate and film quality.

6. Post-Deposition Treatment

Cooling:

• After      deposition is complete, the sputtering power and gas flow are turned off,      allowing the substrate to cool down to room temperature in the vacuum.

7. Substrate Unloading

Return to Atmospheric Pressure:

• Inert gas      (such as nitrogen) is slowly introduced to bring the chamber back to      atmospheric pressure.

Unloading the Substrate:

• The chamber      is opened, and the coated substrate is removed.

8. Quality Inspection

Film Thickness Measurement:

• The film      thickness is measured using a thickness gauge or other measurement      equipment.

Adhesion Testing:

• Adhesion of      the film is tested using methods such as scratch testing.

Surface Morphology and Composition Analysis:

• The film's      surface morphology and composition are analyzed using microscopy, X-ray      photoelectron spectroscopy (XPS), or other analytical equipment.

By following these steps, a high-quality TiN film can be successfully deposited on the substrate surface. Precise control and optimization of each step are crucial to ensuring the quality and performance of the film.