Key Sputtering Parameters for Precursor In₂O₃ Films to Achieve High Carrier Mobility

Area of Science:

• Materials Science
• Thin Film Technology
• Semiconductor Physics

Background:

• Transparent conducting films (TCFs) are crucial for optoelectronic devices.
• Hydrogen-doped indium oxide (IO:H) films offer high carrier mobility and optical transparency.
• Solid-phase crystallization (SPC) of amorphous precursors is vital for achieving desired film properties.

Purpose of the Study:

• To investigate the impact of sputtering parameters on the crystallographic texture of IO:H films during SPC.
• To understand the relationship between sputtering conditions, film microstructure, and carrier transport properties.
• To optimize deposition parameters for high-mobility (>100 cm²/Vs) spc-IO:H films.

Main Methods:

• Systematic investigation of water vapor partial pressure (P_H2O), RF magnetron sputtering power (P_RF), and O₂ flow ratio (fO₂).
• Fabrication of amorphous IO:H precursor films using sputtering.
• Solid-phase crystallization via annealing at 200 °C.
• Analysis of crystallographic texture, microstructure, and carrier transport properties.

Main Results:

• P_H2O, P_RF, and fO₂ are critical for obtaining high-mobility spc-IO:H films.
• Specific conditions (low P_H2O, lower P_RF, suitable fO₂) promote lower crystallite density in precursor films.
• Lower crystallite density in precursor films leads to larger crystal grains after annealing.
• Carrier mobility (μ) in annealed films primarily correlates with stoichiometric deviation.

Conclusions:

• Optimized sputtering parameters are essential for controlling the SPC process and achieving high-performance IO:H films.
• Microstructural control during precursor deposition influences grain growth and ultimately carrier transport.
• Stoichiometric deviation is the dominant factor governing carrier mobility in the final spc-IO:H films.