Analytic bond order potential for indium gallium zinc oxide

Abstract

We report the analytic bond order potential (ABOP) parameters for the molecular dynamics of the indium gallium zinc oxide (IGZO) quarterly compounds. The potential parameters were developed based on first principles calculations and adjusted to follow the experimental observations. Through the phase transition simulation from crystalline to amorphous by the melt-quenching method, the developed potential is in excellent agreement with the experimental observations in the average bond lengths and density changes (from 5.91 g cm⁻³ to 5.69 g cm⁻³) along with good stability at room temperature. To demonstrate the broad applicability of the developed potential, thin film formation by sputtering was simulated. An amorphous phase film of In :Ga : Zn = 1 : 0.93 : 0.58 was successfully reproduced with the sputtering target of InGaZnO₄ under room temperature conditions, which shows good agreement with the experimental results. To find an ideal target composition for the film with few oxygen vacancies, which can induce the negative bias stress, multiple sputtering simulations were performed. The results suggest that the sputtering targets must contain six times higher oxygen contents than the metal components.