Deposition Rate Calculator
Calculate thin-film deposition speed using mass or thickness change
Calculated Deposition Rate
What is Deposition Rate?
In materials science and thin-film technology, the deposition rate is the measurement of the speed at which a material is deposited onto a substrate (such as a silicon wafer). This metric is critical in processes like Physical Vapor Deposition (PVD), Chemical Vapor Deposition (CVD), and electroplating.
Maintaining a consistent deposition rate is essential for controlling film thickness, grain size, and electrical properties of the final product. Even minor fluctuations can lead to defects in semiconductor manufacturing or optical coatings.
The Deposition Rate Formula
While there are several ways to measure this, the gravimetric method (mass-based) is one of the most accurate. The formula used by this calculator is:
R = (m / (ρ × A × t)) × 107
Where:
- R: Deposition Rate (nanometers per minute)
- m: Mass of the deposited material (grams)
- ρ (rho): Density of the material (grams per cubic centimeter)
- A: Surface area of the substrate (square centimeters)
- t: Total deposition time (minutes)
Practical Example:
If you deposit Gold (Density: 19.3 g/cm³) onto a 10 cm² substrate for 10 minutes and the mass increases by 2 mg (0.002 g):
R = (0.002 / (19.3 × 10 × 10)) × 10,000,000 = 10.36 nm/min.
If you deposit Gold (Density: 19.3 g/cm³) onto a 10 cm² substrate for 10 minutes and the mass increases by 2 mg (0.002 g):
R = (0.002 / (19.3 × 10 × 10)) × 10,000,000 = 10.36 nm/min.
Factors Influencing the Rate
Several environmental and system variables affect the deposition speed:
- Source Power: Increasing the voltage or current in sputtering or evaporation usually increases the rate.
- Vacuum Pressure: Lower pressure reduces gas collisions, often allowing for more direct material transfer.
- Substrate Temperature: Temperature affects how atoms migrate and stick to the surface (the sticking coefficient).
- Gas Flow: In CVD, the flow rate of precursor gases determines how much material is available for the reaction.
Common Material Densities
To use the calculator accurately, you need the density of the material being deposited. Here are some common values:
| Material | Density (g/cm³) |
|---|---|
| Aluminum (Al) | 2.70 |
| Gold (Au) | 19.30 |
| Silver (Ag) | 10.49 |
| Titanium (Ti) | 4.50 |
| Copper (Cu) | 8.96 |