Compositional tailoring of indium-free GZO layers via plasma-enhanced atomic layer deposition for highly stable IGZO/GZO TFT

Autor: Hye-Jin Oh, Yoon-Seo Kim, Hyun-Jun Jeong, Sunhee Lee, Joon Seok Park, Jin-Seong Park
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Journal of Information Display, Vol 25, Iss 3, Pp 295-303 (2024)
Druh dokumentu: article
ISSN: 15980316
2158-1606
1598-0316
DOI: 10.1080/15980316.2023.2292465
Popis: Oxide semiconductor-based thin-film transistors (TFTs) are promising candidates for display backplanes and memory device applications. To achieve high device performance and sustain the electrical properties under prolonged operation, it is important to overcome the mobility–stability trade-off in oxide TFTs. Here, we propose a bilayer-structured semiconductor stack formed by plasma-enhanced atomic layer deposition (PEALD), where an indium-free gallium zinc oxide (GZO) film is grown on top of indium gallium zinc oxide (IGZO), to be implemented in top gate devices. Applying a GZO layer (with optimum Ga to Zn ratio) between the IGZO and the gate insulator (GI) resulted in two major effects: interface engineering and band alignment modulation. While maintaining a sufficiently large field effect mobility (31.9 cm2 V−1 s−1), considerable improvements in device reliability were observed concerning positive-bias thermal stress (PBTS) and negative-bias illumination stress (NBIS) compared to TFTs incorporating IGZO single layers. This suggests that proper composition control through PEALD in the bilayer oxide semiconductor TFT may help achieve an appropriate balance between mobility and reliability.
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