A Self-Aligned a-IGZO Thin-Film Transistor Using a New Two-Photo-Mask Process with a Continuous Etching Scheme

作者：Fan Ching Lin^*; Shang Ming Chi; Li Bo Jyun; Lin Yu Zuo; Wang Shea Jue; Lee Win Der

来源：Materials, 2014, 7(8): 5761-5768.

DOI：10.3390/ma7085761

• amorphous indium gallium zinc oxide (a-IGZO)
• back-side exposure
• self-aligned process
• thin-film transistor (TFT)
• two-photo-mask process
• backside-lift-off (BLO)

Minimizing the parasitic capacitance and the number of photo-masks can improve operational speed and reduce fabrication costs. Therefore, in this study, a new two-photo-mask process is proposed that exhibits a self-aligned structure without an etching-stop layer. Combining the backside-ultraviolet (BUV) exposure and backside-lift-off (BLO) schemes can not only prevent the damage when etching the source/drain (S/D) electrodes but also reduce the number of photo-masks required during fabrication and minimize the parasitic capacitance with the decreasing of gate overlap length at same time. Compared with traditional fabrication processes, the proposed process yields that thin-film transistors (TFTs) exhibit comparable field-effect mobility (9.5 cm(2)/V.s), threshold voltage (3.39 V), and subthreshold swing (0.3 V/decade). The delay time of an inverter fabricated using the proposed process was considerably decreased.

• 出版日期2014-8