Chang Che-Jia, Chen Shih-Jie, Chang Tzu-Hsuan, Lee Po-Tsung, Chang Shu-Wei, Lin Shih-Yen
Graduate Institute of Electronics Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan.
Research Center for Applied Sciences, Academia Sinica, No. 128, Sec. 2, Academia Road, Taipei 11529, Taiwan.
ACS Appl Mater Interfaces. 2025 Mar 26;17(12):19020-19025. doi: 10.1021/acsami.4c18855. Epub 2025 Mar 12.
In this work, we realize bilayer molybdenum disulfide (MoS) transistors with in-plane gates on sapphire substrates. Through sequential transferring of MoS, e-beam lithography, and metal lift-off, a device with channel width/length of 500:400 nm is fabricated. With a 250 nm separation between the in-plane gate and MoS channel, a drain current as high as 37 μA with a clear saturation region is observed. The device shows a high ON/OFF current ratio over 10, small gate bias required for current modulation, and high responsivity about 230 A/W when operated in the phototransistor mode. The gain of the phototransistor reaches 432. A quick calculation from the transfer curve using the formula of conventional transistors gives a field-effect mobility of 6365.9 cm·V·s, which, although overestimated, still suggests good performance of the device. With an additional MoS layer to isolate the MoS channel from the influence of the substrate, this dielectric-free in-plane gate transistor has exhibited potential in electronics. The high responsivity of the device under relatively low applied voltages is also promising for weak-light detection.
在这项工作中，我们在蓝宝石衬底上实现了具有平面内栅极的双层二硫化钼（MoS）晶体管。通过依次转移MoS、电子束光刻和金属剥离工艺，制造出了沟道宽度/长度为500:400 nm的器件。在平面内栅极与MoS沟道之间有250 nm的间距时，观察到漏极电流高达37 μA，且具有明显的饱和区。该器件显示出高于10的高开/关电流比、电流调制所需的小栅极偏置，以及在光电晶体管模式下工作时约230 A/W的高响应度。光电晶体管的增益达到432。使用传统晶体管公式从转移曲线进行快速计算得出场效应迁移率为6365.9 cm²·V⁻¹·s⁻¹，尽管该值被高估，但仍表明该器件性能良好。通过额外的MoS层来隔离MoS沟道免受衬底的影响，这种无介质的平面内栅极晶体管在电子学领域展现出了潜力。该器件在相对较低的施加电压下具有高响应度，这对于弱光检测也很有前景。
