Sputtering Deposition Rate Calculator
Calculate thin film growth rates based on measured thickness and process time.
Angstroms (Å)
Nanometers (nm)
Microns (µm)
Minutes
Seconds
Hours
Calculated Deposition Rate
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Å / min
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Å / sec
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nm / min
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µm / hr
Understanding Sputtering Deposition Rate
In the field of Physical Vapor Deposition (PVD), specifically sputtering, the deposition rate is a critical parameter that determines the throughput of a vacuum system and the properties of the resulting thin film. It defines how much material accumulates on the substrate per unit of time.
The Math Behind the Calculation
The fundamental formula for calculating the average deposition rate (R) is straightforward:
R = T / t
- T = Total thickness of the deposited film (measured via profilometry, ellipsometry, or quartz crystal microbalance).
- t = Total time of the sputtering process (excluding ramp-up/ramp-down time).
Common Units in Thin Film Processing
Depending on the industry (Semiconductor, Optics, or Hard Coatings), different units are preferred:
- Angstroms per minute (Å/min): Common in research and semiconductor applications for very thin films.
- Nanometers per minute (nm/min): Often used in general electronics and optical coatings (1 nm = 10 Å).
- Microns per hour (µm/hr): Typical for thick industrial coatings, such as wear-resistant tooling layers.
Factors Influencing Deposition Rate
While this calculator determines the rate experimentally from run data, several process parameters affect the actual rate during sputtering:
- Power Density: Increasing the DC or RF power applied to the target generally increases the sputter yield and deposition rate linearly.
- Process Pressure: Higher pressure can increase the number of Argon ions available to sputter, but too high pressure causes scattering of the sputtered material, reducing the rate at the substrate.
- Target-to-Substrate Distance: The rate drops significantly as the distance increases, following an inverse-square relationship in point-source geometries.
- Material Sputter Yield: Different materials sputter at different rates. For example, Gold (Au) has a much higher sputter yield than Titanium (Ti) under identical conditions.
Why Monitoring Rate is Crucial
Consistent deposition rates ensure film thickness uniformity and repeatability. Variations in rate can indicate target depletion, power supply issues, or changes in gas composition. Using a calculator to verify rates after maintenance or target changes is standard procedure for process engineers.