Kim Jaehyun, Park Joon Bee, Zheng Ding, Kim Joon-Seok, Cheng Yuhua, Park Sung Kyu, Huang Wei, Marks Tobin J, Facchetti Antonio
Department of Chemistry and Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, IL, 60208, USA.
Displays and Devices Research Lab. School of Electrical and Electronics Engineering, Chung-Ang University, Seoul, 06974, Korea.
Adv Mater. 2022 Nov;34(45):e2205871. doi: 10.1002/adma.202205871. Epub 2022 Oct 11.
Thin-film transistors using metal oxide semiconductors are essential in many unconventional electronic devices. Nevertheless, further advances will be necessary to broaden their technological appeal. Here, a new strategy is reported to achieve high-performance solution-processed metal oxide thin-film transistors (MOTFTs) by introducing a metallic micro-island array (M-MIA) on top of the MO back channel, where the MO is a-IGZO (amorphous indium-gallium-zinc-oxide). Here Al-MIAs are fabricated using honeycomb cinnamate cellulose films, created by a scalable breath-figure method, as a shadow mask. For IGZO TFTs, the electron mobility (µ ) increases from ≈3.6 cm V s to near 15.6 cm V s for optimal Al-MIA dimension/coverage of 1.25 µm/51%. The Al-MIA IGZO TFT performance is superior to that of controls using compact/planar Al layers (Al-PL TFTs) and Au-MIAs with the same channel coverage. Kelvin probe force microscopy and technology computer-aided design simulations reveal that charge transfer occurs between the Al and the IGZO channel which is optimized for specific Al-MIA dimensions/surface channel coverages. Furthermore, such Al-MIA IGZO TFTs with a high-k fluoride-doped alumina dielectric exhibit a maximum µ of >50.2 cm V s . This is the first demonstration of a micro-structured MO semiconductor heterojunction with submicrometer resolution metallic arrays for enhanced transistor performance and broad applicability to other devices.
使用金属氧化物半导体的薄膜晶体管在许多非传统电子设备中至关重要。然而，要扩大其技术吸引力，还需要进一步发展。在此，报道了一种新策略，即通过在金属氧化物（MO）背沟道顶部引入金属微岛阵列（M-MIA）来实现高性能溶液处理金属氧化物薄膜晶体管（MOTFT），其中MO为非晶铟镓锌氧化物（a-IGZO）。这里使用通过可扩展的气枕法制备的蜂窝状肉桂酸纤维素膜作为荫罩来制造铝微岛阵列（Al-MIA）。对于IGZO薄膜晶体管，当Al-MIA的最佳尺寸/覆盖率为1.25 µm/51%时，电子迁移率（µ）从约3.6 cm² V⁻¹ s⁻¹增加到接近15.6 cm² V⁻¹ s⁻¹。Al-MIA IGZO薄膜晶体管的性能优于使用致密/平面铝层的对照器件（Al-PL薄膜晶体管）以及具有相同沟道覆盖率的金微岛阵列器件。开尔文探针力显微镜和技术计算机辅助设计模拟表明，在铝和IGZO沟道之间发生了电荷转移，这针对特定的Al-MIA尺寸/表面沟道覆盖率进行了优化。此外，这种具有高k氟掺杂氧化铝电介质的Al-MIA IGZO薄膜晶体管表现出大于50.2 cm² V⁻¹ s⁻¹的最大迁移率。这是首次展示具有亚微米分辨率金属阵列的微结构MO半导体异质结，以增强晶体管性能并广泛适用于其他器件。
