Investigate the relationship between densification and grain size of IGZO target by phase‐field simulation

Abstract

The phase‐field method was employed to simulate the effects of pores on grain growth in the indium gallium zinc oxide (IGZO) targets during conventional and two‐stage sintering (TSS). The findings indicated that the TSS method effectively suppressed the rapid growth of grains. With an increase in porosity and a more prominent pore size, the rate of grain growth accelerated, resulting in the formation of coarser grains. Subsequently, IGZO targets were fabricated using the molding‐cold isostatic pressing (CIP) and TSS methods. The densification activation energies of IGZO green compacts were calculated to be 510 and 370 kJ/mol for CIP at 180 and 250 MPa, respectively, utilizing the main sintering curve (MSC). Additionally, by optimizing the TSS process, a highly dense IGZO target with a relative density of 99.53%, a resistivity of 4.3 mΩ/cm, and an average grain size of 8.59 µm was successfully achieved.