Fabrication of low-temperature bottom-gate poly-Si TFTs on large-area substrate by linear-beam excimer laser crystallization and ion doping method

Abstract

A novel crystallization procedure of Si films using a linearbeam excimer laser combined with a non-mass-separated ion doping method on a large-area is proposed for fabrication of poly-Si TFTs with maximum process temperature of 400°C. Fabricated TFTs show sufficiently high mobilities to drive peripheral circuitry and yet retains a low leakage current suitable to pixel transistors. TFTs' on-current deviation of well under & 20% has been obtained for both nand p-channel TFTs over an entire substrate. Long-term reliability of the TFTs has also been confirmed using a CMOS ring oscillator.

Technology, performance and degradation characteristics of SLS ELA thin film transistors

“…In this way, a very uniform film structure consisting of very elongated grains can be achieved over large areas [7]. Many techniques can be suitable for preselecting the areas that will be fully melted; these include silicon film thickness variation, coating of the a-Si film with a preformed antireflective film and projection shaping of the laser beam profile [8]. One of the excimer laser annealing techniques that yields impressive results is sequential lateral solidification (SLS) [9].…”

Formation of sub-micrometer polycrystalline-SiGe thin-film transistors by using a thinned channel layer

“…Polycrystalline-silicon (poly-Si) thin-film transistors (TFTs) have been studied for its potential using in the static random-access memory (SRAM) and as the integrating peripheral driving circuits in high-resolution active matrix liquid crystal displays due to their large mobility [1,2]. However, because of the defects in polySi TFT devices, some issues have to be resolved in comparison with the single crystalline transistors.…”

Effects of a lightly-doped-drain (LDD) implantation condition on the device characteristics of polycrystalline-Si thin-film transistors

“…Recently, polycrystalline silicon (poly-Si) thin-film transistors have been actively studied for their potential use in static random-access memory (SRAM) [1] and as the integrating peripheral driving circuits in high resolution active matrix liquid crystal displays (AMLCDs) due to their large mobility [2]. However, due to the presence of defects in poly-Si TFT, some issues have to be resolved in comparison with single crystalline transistors.…”