Performance Enhancement of Self-Aligned Coplanar TFTs with ALD-IGZO Channels via Effective Doping from Interlayer Dielectric

A doping technique to form the conductive source/drain regions of self-aligned coplanar thin-film transistors (TFTs) employing In-Ga-Zn-O (IGZO) channels prepared by atomic-layer deposition was uniquely demonstrated. The electrical resistivity of the IGZO film was reduced to 2.88×10 -4 Ω∙cm after simple Al 2 O 3 interlayer dielectric deposition process using H 2 O. The field-effective mobility of the fabricated IGZO TFTs was 23.4 cm 2 /Vs and trustworthy device stabilities were confirmed. Furthermore, small values of the channel width-normalized contact resistance could be obtained to be as low as 8.5 Ω∙cm.