Edge stoichiometry and percolation-governed two-dimensional scaling in amorphous IGZO transistors.

Amorphous indium-gallium-zinc oxide (a-IGZO) transistors are promising back-end-of-line-compatible devices for monolithic three-dimensional logic and memory, but threshold-voltage control becomes challenging as both channel length and width are scaled to the nanoscale. Here, we investigate a-IGZO transistors with both dimensions reduced to 50 nm and show that threshold-voltage scaling is governed by the coupling between edge stoichiometry and percolation-limited transport. Ar- and Cl2-patterned devices exhibit distinct width-dependent threshold-voltage shifts, while length scaling produces an opposite trend. Energy-dispersive spectroscopy, technology computer-aided design simulations, and random telegraph noise measurements reveal that percolative transport amplifies or compensates the impact of edge stoichiometry depending on etch chemistry. These results provide a geometry-process-percolation framework for threshold-voltage engineering in nanoscale oxide electronics.