Abstract

The polycrystalline silicon vertical thin-film transistors (TFTs) with different active layer thicknesses of 150 and 300 nm were fabricated by a five-mask process and electrically characterized. The vertical TFT with 150-nm active layer thickness shows comprehensive advantages over its counterpart with 300-nm active layer, especially with a higher ON/OFF current ratio <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$I_{\mathrm{ON}}/I_{\mathrm{OFF}}$ </tex-math></inline-formula> of more than 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> and higher field-effect mobility, excluding the access resistance effect. The electrical parameters were analyzed by the density of states (DOS) calculation, and smaller DOS is deduced for the device with 150-nm active layer for the same energy level. The detailed elucidation of the DOS was analyzed by introducing the intrinsic mobility and the grain boundary barrier height at the flat-band state, which gives the detailed expressions for the DOS. Polycrystalline silicon lateral TFT was also introduced to verify this evaluation method.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call