Design of InZnSnO Semiconductor Alloys Synthesized by Supercycle Atomic Layer Deposition and Their Rollable Applications

Abstract

Amorphous InGaZnO semiconductors have been rapidly developed as active charge-transport materials in thin film transistors (TFTs) because of their cost effectiveness, flexibility, and homogeneous characteristics for large-area applications. Recently, InZnSnO (IZTO) with superior mobility (higher than 20 cm2 V–1 s–1) has been suggested as a promising oxide semiconductor material for high-resolution, large-area displays. However, the electrical and physical characteristics of IZTO have not been fully characterized. In this study, thin IZTO films were grown using a novel atomic layer deposition (ALD) supercycle process consisting of alternating subcycles of single-oxide deposition. By varying the number of deposition subcycles, it was determined that the insertion of a Sn–O cycle improved the mobility and reliability of IZTO-based TFTs. Specifically, the IZTO TFT obtained using one In–O cycle, one Zn–O cycle, and one Sn–O exhibited the best performance (saturation mobility of 27.8 cm2 V–1 s–1 and threshold voltage shift of 1.8 V after applying positive-bias temperature stress conditions). Next, the production of rollable and flexible devices was demonstrated by fabricating ALD-processed IZTO TFTs on polymer substrates. The electrical characteristics of these TFTs were retained without drastic degradation for 240,000 bending cycles. These results indicate that the supercycle ALD technique is effective for synthesizing multicomponent oxide TFTs for electronic applications requiring high mobility and mechanical flexibility.

Complementary Hybrid Semiconducting Superlattices with Multiple Channels and Mutual Stabilization

“…In addition, various gate-bias stability tests including positive bias stress (PBS), negative bias stress (NBS), and positive bias illumination stress (PBIS) also confirmed the nearly unchanged performance of the hybrid superlattice FET (Figure S10, Supporting Information). These results indicate that 4MP/ZnO hybrid superlattices surpass bias and illumination stability of oxide semiconductors. , Note that the hybrid superlattices were also thermally stable in the air up to 300 °C.…”

Recent progress and perspectives on atomic‐layer‐deposited semiconducting oxides for transistor applications

“…Although binary metal‐oxide channel systems offer simple composition and processing, securing the high mobility and controllability of V TH and excellent I ON/OFF ratio simultaneously can be difficult. To overcome this limit of binary oxides, multi‐component oxide materials such as ternary (indium gallium oxide [IGO], 55–57 indium zinc oxide [IZO], 58–60 and zinc tin oxide [ZTO] 61,62 ) and quaternary oxide (indium gallium zinc oxide [IGZO], 63–68 and indium zinc tin oxide [IZTO] 69,70 ) species have been examined as active‐material candidates for high‐performance TFTs. The design rationale should balance mobility enhancement and carrier suppression.…”

ZnO‐Reinforced Thermal Regulating Microcapsules with Double‐Layer Shell via Atomic Layer Deposition

“…Benefiting from the above virtues, ALD has been considered to have broad prospects in the fields of solar cells, [ 19,20 ] biomaterials, [ 21 ] and semiconductors. [ 22,23 ] In previous research, various inorganic materials, such as alumina (Al 2 O 3 ), [ 24 ] TiO 2 , [ 25,26 ] and ZnO, [ 27 ] have been coated onto the surface of organic substrate, and it has been confirmed that ALD induced coating has adhesive rigidity and durability.…”