Copper Tin Halide p-Type TFT Enabled Solution Processed Monolithic 3D CMOS Circuits

A critical requirement for low-power microelectronics is the construction of logic circuits using complementary devices. In pursuit of low-power solution-processed thin film Complementary Metal Oxide Semiconductor (CMOS) circuits, significant research is expended toward producing the elusive p-type transistors. Beyond the challenges associated with processability and formulation complexity of existing metal halide solutions, they critically do not attain the electrical properties required to build productive devices. For the first time, this work describes high-performance solution-processed p-type thin film transistors developed using copper tin halide. Incorporating tin and high electronegativity halide species (Cl-/F-) improves CuI film morphology, stability, and electrical properties through copper/tin vacancy suppression, which results in high mobility, over 20 cm² Vs⁻¹, and low operating voltage Thin Film Transistors (TFTs). Furthermore, the p-type TFTs are able to be integrated with fully solution-processed n-type Indium Gallium Zinc Oxide (IGZO) TFTs in a highly transparent multilayer stack architecture. The monolithic 3D (M3D) CMOS design records inverter gains of 20 at V_DD = 3V, demonstrating p-type devices fabricated using solution processing have the requisite high performance required for productive solution-processed multilayer microelectronics.