Title :
A 10-s doping technology for the application of low-temperature polysilicon TFTs to giant microelectronics
Author :
Mimura, Akio ; Kawachi, Genshiro ; Aoyama, Takashi ; Suzuki, Takaya ; Nagae, Yoshiharu ; Konishi, Nobutake ; Mochizuki, Yasuhiro
Author_Institution :
Res. Lab., Hitachi Ltd., Ibaraki, Japan
fDate :
3/1/1993 12:00:00 AM
Abstract :
A bucket-type high-density (0.25-1.2-mA/cm2) low-energy (500-2000 V) ion source was utilized for high-speed phosphorus doping directly into a thin polysilicon layer without cap SiO2. Doping gas with He dilution was selected to reduce etching of polysilicon film. Excimer laser (XeCl, 8 mm×8 mm) pulse annealing was introduced to activate effectively the doped impurity. The combination of these techniques provided a practically low sheet resistance for the TFT source, drain, and gate with a short time doping. The low-temperature polysilicon TFT fabricated with a doping time of 10 s had characteristics comparable to those of that fabricated by a longer time doping or conventional ion implantation, showing the practicality of this technology and its promise for giant microelectronics
Keywords :
ion implantation; laser beam annealing; phosphorus; semiconductor doping; thin film transistors; 10 s; 500 to 2000 V; TFT characteristics; activation; doping technology; doping time; giant microelectronics; high speed doping; laser annealing; low energy ion source; low-temperature polysilicon TFTs; polycrystalline Si:P; sheet resistance; short time doping; Annealing; Doping; Etching; Gas lasers; Helium; Impurities; Ion implantation; Ion sources; Optical pulses; Thin film transistors;
Journal_Title :
Electron Devices, IEEE Transactions on
