Performance Degradation of Flexible Si Nanomembrane Transistors With Al2O3 and SiO2 Dielectrics Under Mechanical Stress

Flexible Si nanomembrane transistors with Al
₂
O
₃
and SiO
₂
gate dielectrics were fabricated, and their mechanical stability was compared under various bending conditions. Both the Al
₂
O
₃
and SiO
₂
gate dielectric devices exhibited good charge transport properties, which was associated with the advantage of having a fully depleted mode in the MOSFET operation. The results of the comparison showed that the Al
₂
O
₃
gate dielectric device degraded to a greater extent than the SiO
₂
gate dielectric device under the same bending condition. The greater degradation in the Al
₂
O
₃
gate dielectric device was attributed to the higher Young's modulus of the Al
₂
O
₃
, which put more strain on the Al
₂
O
₃
under the same bending condition.