AuGe-Alloy Source and Drain Formation by the Lift-Off Process for the Scaling of Bottom-Contact Type Pentacene-Based OFETs

Shun-ichiro OHMI  Mizuha HIROKI  Yasutaka MAEDA  

IEICE TRANSACTIONS on Electronics   Vol.E102-C   No.2   pp.138-142
Publication Date: 2019/02/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.2018OMP0008
Type of Manuscript: Special Section PAPER (Special Section on Recent Progress in Organic Molecular Electronics and Biotechnology)
AuGe,  bottom-contact,  pentacene,  OFET,  lift-off,  yield,  SPM cleaning,  PMA process,  

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The AuGe-alloy source and drain (S/D) formed on SiO2/Si(100) by the lithography process was investigated for the scaling of the organic field-effect transistors (OFETs) with bottom-contact geometry. The S/D was fabricated by the lift-off process utilizing the resist of OFPR. The OFETs with minimum channel length of 2.4 µm was successfully fabricated by the lift-off process. The fabrication yield of Au S/D was 57%, while it was increased to 93% and 100% in case of the Au-1%Ge and Au-7.4%Ge S/D, respectively. Although the mobility of the OFETs with Au-7.4%Ge S/D was decreased to 1.1×10-3 cm2/(Vs), it was able to be increased to 5.5×10-2 cm2/(Vs) by the surface cleaning utilizing H2SO4/H2O2 mixture solution (SPM) and post metallization annealing (PMA) after lift-off process, which was higher than that of OFET with Au S/D.