Tin Oxide Based P and N-Type Thin Film Transistors Developed by RF Sputtering

Tin oxide has been demonstrated as an ideal material for fabricating p-type and n-type thin film transistors (TFTs) for transparent CMOS type device fabrication. Both p and n-type conduction was observed in the thin films, prepared from metallic tin target by simply varying the oxygen flow rate during RF magnetron sputter deposition. Films deposited at room temperature were amorphous in nature, which after annealing at 200°C in air, crystallized to SnO and/or SnO 2 phases. The TFTs fabricated on thermally oxidized silicon substrates showed high field effect mobility of 4.13 and 16 cm 2 /Vs with drain current on-off ratio 6 × 10 2 and 10 7 respectively for SnO p-type and SnO 2 n-type TFTs. These are the highest values for p-type and n-type oxide TFTs fabricated from same source material.