Extended Data Fig. 3: Thickness verification of ultrathin HZO films using TEM.
From: Enhanced ferroelectricity in ultrathin films grown directly on silicon
a, HZO thickness as a function of ALD cycles, as determined by Si atomic lattice calibration from TEM imaging. The growth rate is ∼11 cycles nm−1, verified across 10–50 ALD cycle films, consistent with XRR (Extended Data Fig. 2). The red error bars reflect 2σ variation. b, Cross-sectional ADF STEM image of 20 cycles HZO. c–e, Cross-section TEM images of ten-cycle HZO (c), 15-cycle HZO (d) and 40-cycle HZO (e). f–h, Wide field-of-view TEM images of ten-cycle HZO (f), 15-cycle HZO (g) and 40-cycle HZO (h) to provide a perspective of the heterostructure uniformity. The Si substrate is oriented along the [110] zone axis for all TEM images.
