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

Heterojunction formation is the key to adjusting the electronic and optoelectronic properties of various semiconductor devices. There have been various reports on the formation and importance of semiconducting heterojunction devices based on metal oxides. Titanium dioxide (TiO₂) is one of the metal oxides that has many unique properties. TiO₂'s importance is due to its physical and chemical properties such as large band gap, large permittivity, stability, and low leakage current density. In this context, we present the electrical properties of the metal-insulator-semiconductor (MIS) type-TiO₂-based Schottky barrier diode (SBD) in the study. To create a thin layer of TiO₂ on p-type silicon (p-type Si) patterned partially by the laser-induced periodic surface structure (LIPSS) technique, an atomic layer deposition (ALD) technique was used in the study. For comparison, the current-voltage (I-V) characteristics of the TiO₂-based laser-patterned (LP) and nonlaser-patterned (non-LP) diodes were measured at 300 K and in the dark at ±5 V. Classical thermionic emission (TE) theory and Cheung functions were used to investigate the critical diode parameters of the diodes, including ideality factor (n), series resistance (R_s), and barrier height (Φ_b). The n values were obtained as 4.10 and 3.68 from the TE method and Cheung functions for the LP diode, respectively. The Φ_b values were found as 0.68 and 0.69 eV from the TE method and Cheung functions, respectively. According to experimental results, the laser patterning resulted in an increase in the Φ_b values and a decrease in the n values. After laser patterning, it was observed that the device worked effectively, and the ideality factor and barrier height values were improved. This study provides insight into the fabrication and electrical properties of TiO₂-based heterojunction devices.