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}\times {10} ^{-{4}}\,\,\Omega \cdot $ cm after simple Al ₂ O ₃ interlayer dielectric deposition process using $\text{H}_{{2}}\text{O}$ . The field-effective mobility of the fabricated IGZO TFTs was 23.4 cm ² /V.s 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~\Omega \cdot $ cm.