High performance LTPS TFT with very large grains produced  by  sequential lateral crystallization

The European Physical Journal Applied Physics

The European Physical Journal Applied Physics / Volume 31 / Issue 03 / September 2005, pp 165-168
© EDP Sciences, 2005
Published online by Cambridge University Press: 10 February 2011
DOI: http://dx.doi.org/10.1051/epjap:2005057 (About DOI)

Table of Contents - September 2005 - Volume 31, Issue 03

Semiconductors and Devices

High performance LTPS TFT with very large grains produced by sequential lateral crystallization

S. J. Park^a1, S. H. Kang^a1, Y. M. Ku^a1 and J. Jang^a1

Advanced Display Research Center and Department of Physics, Kyung Hee University, Dongdaemoon-ku, Seoul 130-701, Korea

Abstract

We report the structural and electrical properties of polycrystalline silicon on glass crystallized by using a CW Nd:YVO₄ laser. Various microstructures appear on amorphous silicon after a scanning of the laser regardless of the crystallization process parameters such as laser power and scan speed. The crystallized region could be characterized by their grain size as 3 distinct regions; RTA-SPC (rapid thermal annealed-solid phase crystallization) region, small-grain region and SLC (sequential lateral crystallization) region with very large grains of ~10 μm. To verify its electrical properties, p-ch TFTs were fabricated on the 3 different regions. The characteristics of TFTs on SLC region were superior to those on other regions and average performances of SLC poly-Si TFTs were $u_{\rm fe} = 132$ cm²/V s, $V_{\rm th} = -4.6$ V, S.S. = 0.5 V/dec, and $I_{\rm off} =\,\sim 1$ pA/μm at $V_{d} = -10$ V, respectively.