In Situ Fluorine Doping of FZO Films by Atomic Layer Deposition

Area of Science:

• Materials Science
• Semiconductor Physics
• Chemical Engineering

Background:

• Fluorine-doped semiconductors are crucial for optoelectronic devices.
• Atomic Layer Deposition (ALD) offers precise thin-film deposition for complex structures.
• A significant challenge in ALD has been the lack of effective fluorine precursors.

Purpose of the Study:

• To achieve fluorine doping in ZnO thin films using ALD.
• To demonstrate the efficacy of a new homemade ammonium fluoride/water precursor.
• To investigate the mechanism and optimize conditions for fluorine incorporation.

Main Methods:

• Utilized Atomic Layer Deposition (ALD) to deposit fluorine-doped ZnO (FZO) thin films.
• Employed a novel homemade precursor mixture: ammonium fluoride/deionized water (NH4F/DI).
• Systematically varied ALD growth temperature, canister temperature, and precursor concentration.

Main Results:

• Successfully deposited FZO thin films using the NH4F/DI precursor.
• Identified optimal conditions: 180 °C growth temperature, 30% NH4F/DI concentration, 40 °C canister temperature.
• Achieved a fluorine incorporation of 2.62 atomic percent (at. %) under optimized conditions.

Conclusions:

• The NH4F/DI precursor mixture is effective for ALD-based fluorine doping of ZnO.
• ALD offers a viable, low-temperature, budget-friendly method for producing FZO films.
• Optimized conditions enable controlled fluorine incorporation, impacting film properties.