Semiconductor device with a gate insulating layer having increased Al—O bond energy, a diffusion-supressing interface layer between a gate insulating layer and a channel structure, and capacitor structures on channel structures

A semiconductor device, comprising

• a substrate,
• first conductive lines disposed on the substrate, spaced apart from each other in a first direction, and extending in a second direction,
• channel structures disposed on the first conductive lines, spaced apart from each other in the first and second directions, and extending in a third direction crossing the first and second directions,
• gate electrodes disposed between the channel structures and extending in a first direction,
• a gate insulating layer disposed between a channel structure of the channel structures and a gate electrode of the gate electrodes, and
• capacitor structures disposed on the channel structures,
• wherein the gate insulating layer has a ratio (%) of an Al—O peak observed at a binding energy of about 530.3 eV to about 531.6 eV to all peaks of greater than or equal to about 80% in an XPS spectrum of O 1s obtained by an X-ray photoelectron spectroscopy (XPS) using a monochromatic aluminum Kα (1486.6 eV) source.