Title :
A novel self-aligned bottom gate poly-Si TFT with in-situ LDD
Author :
Shengdong Zhan ; Han, Ruqi ; Chan, Mansun J.
Author_Institution :
Inst. of Microelectron., Beijing Univ., China
Abstract :
A lithography independent self-aligned bottom gate thin film transistor (SABG-TFT) technology is proposed and experimentally demonstrated. The unique feature of the technology is the formation of self-aligned and symmetrical lightly doped source/drain (LDD) structure without any additional photolithographic or implantation steps. Thus, the number of masks used in the technology is the same as that in a conventional top gate TFT technology. Moreover, devices formed by the proposed method have thick source/drain and a thin channel region for providing low source/drain resistance and improved I-V characteristics. P-channel TFT devices are fabricated using a simple low temperature (/spl les/600/spl deg/C) process. The fabricated SABG-TFT exhibits symmetrical transfer characteristics when the polarity of source/drain bias is reversed. The effective mobility and on-off current ratio of the devices are about 35 cm/sup 2//V-s and 6/spl times/10/sup 6/ respectively.
Keywords :
carrier mobility; semiconductor device measurement; semiconductor technology; thin film transistors; 600 C; I-V characteristics; effective mobility; in-situ LDD; lithography independent self-aligned bottom gate thin film transistor; low source/drain resistance; low temperature process; on-off current ratio; reverse source/drain bias polarity; self-aligned bottom gate poly-Si TFT; self-aligned symmetrical lightly doped source/drain structure; symmetrical transfer characteristics; thick source/drain; thin channel region; Application specific integrated circuits; Fabrication; Flat panel displays; Inorganic materials; Lithography; Parasitic capacitance; Substrates; Surfaces; Temperature; Thin film transistors;
Journal_Title :
Electron Device Letters, IEEE
