Title :
Fabrication of thin film transistors using a Si/Si/sub 1-x/Ge/sub x//Si triple layer film on a SiO2 substrate
Author :
Kim, Jin Hyeok ; Lee, Jeong Yong ; Kim, Hong Seung ; Song, Yoon-Ho ; Nam, Kee-Soo
Author_Institution :
Dept. of Mater. Sci. & Eng., Korea Adv. Inst. of Sci. & Technol., Taejon, South Korea
fDate :
5/1/1996 12:00:00 AM
Abstract :
A novel approach that can reduce the thermal budget in the fabrication of thin film transistors (TFTs) using a Si/Si/sub 0.7/Ge/sub 0.3//Si triple film as an active layer was proposed. The crystallization behavior of the triple film was described and device characteristics of Si/Si/sub 0.7/Ge/sub 0.3//Si TFTs were compared with those of Si TFTs and of SiGe TFTs. The triple film was completely crystallized only after a 25-h anneal at 550/spl deg/C. N-channel polycrystalline Si/Si/sub 0.7/Ge/sub 0.3//Si TFTs had a field-effect mobility of 57.9 cm/sup 2//Vs and an I/sub on//I/sub off/ ratio of 5.7/spl times/10/sup 6/. This technique provides not only a shorter time processing capability than Si TFT´s technology but also superior device characteristics compared to SiGe TFTs.
Keywords :
Ge-Si alloys; MOSFET; annealing; carrier mobility; chemical vapour deposition; crystallisation; elemental semiconductors; semiconductor materials; silicon; thin film transistors; vapour phase epitaxial growth; 25 h; 550 C; N-channel polycrystalline devices; Si-SiGe-Si; Si/Si/sub 1-x/Ge/sub x//Si triple layer film; SiO/sub 2/; SiO/sub 2/ substrate; TFT fabrication; annealing; crystallization behavior; device characteristics; field-effect mobility; thermal budget reduction; thin film transistors; Active matrix liquid crystal displays; Amorphous materials; Annealing; Crystallization; Electrons; Fabrication; Germanium silicon alloys; Semiconductor films; Silicon germanium; Thin film transistors;
Journal_Title :
Electron Device Letters, IEEE
