Demonstration of High Performance Flexible In0.7Ga0.3As MOSFETs Using Liquid Polyimide (LPI) Transfer

In this work, flexible In
_0.7
Ga
_0.3
As metal-oxide-semiconductor field-effect-transistors (MOSFETs) are demonstrated by utilizing liquid polyimide (LPI) transfer. The flexible In
_0.7
Ga
_0.3
As MOSFET on polyimide showed excellent logic performances including threshold voltage (V
_th
) = 0.16 V, subthreshold swing (SS) = 95 mV/dec and drain induced barrier lowering (DIBL) = 64 mV/V with
$\text{L}_{\mathbf {g}} \text {= 5}\,\, \boldsymbol {\mu }\text{m}$
at V
_DS
= 0.5 V. In addition, ex-situ bending experiment was employed to demonstrate electro-mechanical performance, which include stable I
_on
/I
_off
ratio and R
_on
from 85 mm to 9 mm of bending radius, and deviation of subthreshold swing is less than 5.3 % under bending radius from 85 mm to 4 mm. Our findings indicate that the LPI transfer method on fabricated devices without additional complex bonding methods would be one of effective solutions to enable flexible III-V compound semiconductor electronics and opto-electronic devices.