A self-aligned fabrication process for top-gate amorphous zinc-tin oxide (a-ZTO) thin-film transistors (TFTs) is developed, in which the source/drain (S/D) doping is realized through depositing a thin aluminum (Al) film on S/D regions and performing a thermal annealing. Results indicate that a chemical oxidation-reduction reaction between Al and a-ZTO films takes place during the thermal annealing process, and shallow donors of oxygen vacancies and metal tin (Sn) interstitials are thus generated. The formed S/D regions have a high carrier concentration over $1 \times 10 ^{20}$ cm $^{-3}$ , low sheet resistance of 0.57 k $ {\Omega }$ /sq, and high thermal stability even in oxygen ambient. The fabricated a-ZTO TFTs exhibit excellent electrical performances, including a low channel-width-normalized S/D resistance of about $7.05~ {\Omega }$ cm, a high field-effect mobility of 15.7 cm ² /Vs, a high on/off current ratio of over $10 ^{8}$ , and near-zero turn-on voltage. Moreover, good electrical stability with less than 0.2-V threshold voltage shift under ±30-V gate bias stresses is also achieved.

中文翻译：

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源/漏区铝反应掺杂的自对准顶栅非晶氧化锌锡薄膜晶体管


开发了顶栅非晶氧化锌锡（a-ZTO）薄膜晶体管（TFT）的自对准制造工艺，其中通过沉积薄铝（ Al)在S/D区域上形成薄膜并进行热退火。结果表明，Al和a-ZTO薄膜在热退火过程中发生化学氧化还原反应，从而产生氧空位的浅施主和金属锡（Sn）填隙。形成的S/D区具有超过$1 \times 10 ^{20}$ cm $^{-3}$的高载流子浓度、0.57 k $ {\Omega }$ /sq的低薄层电阻以及高热稳定性在氧气环境中。所制造的a-ZTO TFT表现出优异的电性能，包括约$7.05~ {\Omega }$ cm的低沟道宽度归一化S/D电阻、15.7 cm ² /Vs的高场效应迁移率、高导通电阻。 /off 电流比超过 $10 ^{8}$ ，并且开启电压接近于零。此外，还实现了良好的电气稳定性，在 ±30V 栅极偏置应力下阈值电压漂移小于 0.2V。