Title :
Improved thin-film transistor (TFT) characteristics on chemical-mechanically polished polycrystalline silicon film
Author :
Chan, Alain C K ; Mansun Chan ; Ko, Ping K.
Author_Institution :
Dept. of Electr. & Electron. Eng., Hong Kong Univ. of Sci. & Technol., Hong Kong
Abstract :
A standard CMP (chemical mechanical polishing) process has been used to reduce surface roughness of a polysilicon thin film. An N-channel TFT has been fabricated on both polished and unpolished polysilicon thin films. Both thin thermally grown and deposited oxides with thickness under 30 nm are used as the gate dielectric. It is founded that a TFT fabricated on polished polysilicon thin film exhibits higher carrier mobility, better sub-threshold swing, lower threshold voltage, higher on/off current ratio as well as better ability to withstand high voltage operation and longer device lifetime. Such improvement should benefit applications which incorporate TFT such as SRAM and LCD display
Keywords :
carrier mobility; chemical mechanical polishing; elemental semiconductors; silicon; surface topography; thin film transistors; LCD display; SRAM; Si; TFT; carrier mobility; chemical mechanical polishing; device lifetime; high voltage operation; on/off current ratio; polysilicon thin film; sub-threshold swing; surface roughness; thin-film transistor; threshold voltage; Capacitors; Chemical processes; Chemical technology; Dielectric thin films; Rough surfaces; Semiconductor films; Silicon; Surface roughness; Thin film transistors; Threshold voltage;
Conference_Titel :
Electron Devices Meeting, 1999. Proceedings. 1999 IEEE Hong Kong
Conference_Location :
Shatin
Print_ISBN :
0-7803-5648-9
DOI :
10.1109/HKEDM.1999.836403
