Electrical Properties of Laser Patterned Schottky Diode with ALD-Grown TiO₂ Interlayer.

Area of Science:

• Materials Science
• Semiconductor Physics
• Device Engineering

Background:

• Heterojunctions are crucial for semiconductor devices, with metal oxides like titanium dioxide (TiO2) offering unique electronic and optoelectronic properties.
• TiO2 exhibits desirable characteristics including a large band gap, high permittivity, stability, and low leakage current density.
• Schottky barrier diodes (SBDs) are fundamental semiconductor devices where heterojunction formation significantly impacts performance.

Purpose of the Study:

• To investigate the electrical properties of metal-insulator-semiconductor (MIS) type TiO2-based SBDs.
• To evaluate the effect of laser-induced periodic surface structure (LIPSS) patterning on TiO2 thin films for diode fabrication.
• To compare the performance of laser-patterned (LP) and non-laser-patterned (non-LP) TiO2/p-type Si diodes.

Main Methods:

• Fabrication of TiO2 thin films on p-type silicon using atomic layer deposition (ALD).
• Partial patterning of the TiO2 layer using laser-induced periodic surface structure (LIPSS) technique.
• Measurement of current-voltage (I-V) characteristics at 300 K in the dark for both LP and non-LP diodes.
• Analysis of diode parameters (ideality factor, series resistance, barrier height) using classical thermionic emission (TE) theory and Cheung functions.

Main Results:

• Laser patterning of TiO2 on p-type silicon resulted in improved diode characteristics.
• The ideality factor (n) decreased from 4.10 (TE) / 3.68 (Cheung) for non-LP to improved values for LP diodes.
• The barrier height (Φb) increased from 0.68 eV (TE) / 0.69 eV (Cheung) for non-LP to improved values for LP diodes.
• Laser patterning led to a significant enhancement in the performance of TiO2-based SBDs.

Conclusions:

• Laser patterning is an effective technique for improving the electrical properties of TiO2-based heterojunction devices.
• The study demonstrates enhanced barrier height and reduced ideality factor in laser-patterned diodes.
• The findings offer valuable insights into the fabrication and optimization of advanced TiO2-based electronic devices.