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

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 m omega/cm, and an average grain size of 8.59 mu m was successfully achieved.