Single-crystalline Ge p-channel thin-film transistors with Schottky-barrier source/drain on flexible polyimide substrates

We fabricated the single-crystalline Ge (sc-Ge) p-channel thin-film transistors (TFTs) with Schottky-barrier source/drain (S/D) on flexible polyimide substrates by a simplified low-temperature process (≤ 250°C), which preserves the high mobility Ge channel. Adhesive wafer bonding and Smart-Cut techniques were utilized to transfer the sc-Ge thin film onto polyimide substrates. The device has a linear hole mobility of ~170 cm
²
V
^-1
s
^-1
, saturation hole mobility of ~120 cm
²
V
^-1
s
^-1
, and I
_on
of ~1.6 μA/μm at V
_d
= -1.5 V for the channel width/length = 280/15μm.