Nanometer‐Precision Top‐Contact Electronics Enabled by Polyimide Shadow Masks on Solution‐Processed IGZO and Organic Semiconductors

Shadow masks provide a scalable route for additive patterning, yet their resolution is fundamentally limited by imperfect stencil–substrate contact and edge irregularities that propagate into deposited structures. Here, we develop a polyimide (PI) soft‐stencil platform that enables high‐precision top‐contact patterning from the sub‐50 nm regime to several micrometers. This approach combines electrostatic stencil adhesion with thermally induced polymer encapsulation to actively reconstruct stencil boundaries, transforming irregular aperture edges into smooth and vertically well‐defined ones. The edge‐refined stencil ensures uniform pattern transfer during vacuum deposition, enabling the fabrication of sharply defined semiconductor pixels and sub‐50 nm nanogap channels through self‐aligned oblique‐angle deposition. Device demonstrations, including nanoscale organic rectifying junctions and short‐channel oxide transistors, confirm the formation of clean top‐contact interfaces and accurately controlled channel dimensions, highlighting the potential of this strategy for constructing high‐precision, self‐aligned, and complex device architectures for advanced (opto‐)electronic applications.