Physically driven coupling of defect activation and structural rearrangement in low-temperature In2O3 films via in-cycle Ar plasma

초록

Transparent conducting oxide (TCO) films grown under low thermal budgets often suffer from trade-offs between structural ordering and electrical performance, hindering their integration into next-generation OLED displays. In this study, we demonstrate an in-cycle Ar plasma-assisted plasma-enhanced atomic layer deposition (PEALD) strategy for growing In2O3 films at 100 degrees C. Ar plasma serves as a physically driven, non-thermal energy-transfer source that compensates for the thermal energy deficit during film growth. This process increased the surface energy, as evidenced by the reduced contact angle, while preserving the self-limiting growth behavior. More importantly, the in-cycle Ar plasma selectively increased the oxygen vacancy concentration without significantly changing the overall O/In stoichiometry, and the corresponding valence band shift confirmed donor-like electronic activation. Simultaneously, Ar plasma promoted crystallization, (400) texture development, film densification, and surface smoothing. Consequently, a low resistivity of 1.1 & times; 10-3 Omega cm was achieved at 250 W through a balance between carrier activation and mobility recovery. The films also maintained high visible transparency of up to 84.9%, supported by improved crystallinity and reduced optical scattering. These results show that in-cycle Ar plasma couples defect activation with structural rearrangement through physical energy transfer, enabling low-temperature In2O3 films with improved electrical conductivity and high optical transparency for heat-sensitive optoelectronic devices.

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