Characterization of 3D Trench PZT Capacitors for High Density FRAM Devices by Synchrotron X‐ray Micro‐diffraction

3D trench PbZrxTi1−xO3 (PZT) capacitors for 256 Mbit 1T‐1C FRAM devices were characterized by synchrotron X‐ray micro‐diffraction at Pohang Light Source. Three layes, Ir/PZT/Ir were deposited on SiO2 trench holes with different widths ranging from 180 nm to 810 nm and 400 nm in depth by ALD and MOCVD. Each hole is separated from neighboring holes by 200 nm. The cross sectional TEM analysis for the trenches revealed that the PZT layers were consisted of columnar grains at the trench entrance and changes to polycrystalline granular grains at the lower part of the trench. The transition from columnar to granular grains was dependent on the trench size. The smaller trenches were favorable to granular grain formation. High resolution synchrotron X‐ray diffraction analysis was performed to determine the crystal structure of each region. The beam was focused to about 500 μm and the diffraction patterns were obtained from a single trench. Only the peaks corresponding to ferroelectric tetragonal phases are observe...