Advancements in High-Mobility SnO2-Based Thin-Film Transistors: Unleashing the Potential for Next-Generation Electronics

The 7 nm nanosheet tin oxynitride (SnON) with 7.6 % nitrogen thin film transistor (TFT) exhibits a record high field-effect mobility (TFE) of 299 cm
²
N-s. The 5 nm thick nanosheet SnON TFT showed µ
FE
of 277 cm
²
N-s compared to control SnO
2
device µ
FE
of 211 cm
²
N-s with the same 5 nm thickness. According to quantum-mechanical calculations, the reason for the high µ
FE
of nanosheet SnON TFT is its lower effective mass of electrons in the conduction band, which is 0.29 mo, compared to 0.41 mo for SnO
2
. By injecting non-oxide anions and controlling the valence band by substitutional alloying with nitrogen anions, SnON can further lower defect trap densities, boost on-current (I
ON
), and improve the transistor's mobility. This allows for the removal or passivation of oxygen vacancy levels. The SnON TFT device can be extensively deployed in advanced high-definition displays and monolithic 3D ICs.