Yoon Chan Sic, Kim Hyung Tae, Kim Min Seong, Yoo Hyukjoon, Park Jeong Woo, Choi Dong Hyun, Kim Dongwoo, Kim Hyun Jae
School of Electrical and Electronic Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
ACS Appl Mater Interfaces. 2021 Jan 27;13(3):4110-4116. doi: 10.1021/acsami.0c15017. Epub 2021 Jan 15.
We investigated a facile fabrication method, which is an insertion of a carrier-induced interlayer (CII) between the oxygen-rich a-IGZO channel and the gate insulator to improve the electrical characteristics and stability of amorphous indium-gallium-zinc-oxide thin-film transistors (a-IGZO TFTs). The a-IGZO channel is deposited with additional oxygen gas flow during a-IGZO channel deposition to improve the stability of the a-IGZO TFTs. The CII is a less than 10 nm thick deposited thin film that acts to absorb the oxygen from the a-IGZO front channel through oxidation. Through oxidation of the CII, the oxygen concentration of the a-IGZO front channel is decreased compared to that of the oxygen-rich back channel, which forms a vertically graded oxygen deficiency (VGO) in the a-IGZO channel. Therefore, the electrical characteristics of the VGO TFTs are improved by increasing the carrier concentration of the front channel as the oxygen vacancy concentration in the front channel is increased through the oxidation of the CII. At the same time, the stability of the VGO TFTs is improved by maintaining a high oxygen concentration in the back channel even after oxidation of the CII. The field-effect mobility (μ) of the VGO TFTs improved compared to that of the a-IGZO TFTs from 7.16 ± 0.6 to 12.0 ± 0.7 cm/V·s. The threshold voltage () shifts under positive bias temperature stress and negative bias temperature illumination stress decreased from 6.00 to 2.95 V and -15.58 to -8.99 V, respectively.
我们研究了一种简便的制造方法，即在富氧的非晶铟镓锌氧化物（a-IGZO）沟道与栅极绝缘体之间插入载流子诱导中间层（CII），以改善非晶铟镓锌氧化物薄膜晶体管（a-IGZO TFTs）的电学特性和稳定性。在a-IGZO沟道沉积过程中，通过额外的氧气流来沉积a-IGZO沟道，以提高a-IGZO TFTs的稳定性。CII是一层厚度小于10nm的沉积薄膜，其作用是通过氧化从a-IGZO前沟道吸收氧气。通过CII的氧化，与富氧的后沟道相比，a-IGZO前沟道的氧浓度降低，这在a-IGZO沟道中形成了垂直渐变的氧缺陷（VGO）。因此，随着通过CII的氧化，前沟道中的氧空位浓度增加，前沟道的载流子浓度增加，从而改善了VGO TFTs的电学特性。同时，即使在CII氧化后，通过在后沟道中保持高氧浓度，也提高了VGO TFTs的稳定性。与a-IGZO TFTs相比，VGO TFTs的场效应迁移率（μ）从7.16±0.6提高到12.0±0.7 cm²/V·s。在正偏压温度应力和负偏压温度光照应力下，阈值电压（）的偏移分别从6.00降低到2.95V和从-15.58降低到-8.99V。
