48.1: Inline Low Temperature Polycrystalline Silicon Roughness and Grain Size Metrology Enabled by Electron Beam Review for a Better Process Control of Excimer Laser Annealing

Abstract

In this paper, we present a brand new inline metrology solution for LTPS roughness enabled by EBR system. It was the first time that LTPS roughness inline measurement was made possible in display manufacturing industry. Moreover, a broader perspective for process monitoring was added to the existing grain size measurement function. The metrology showed the advantages of faster cycle time, non‐destructive, and extremely higher sampling rate. Several experiments were performed to show good sensitivity between roughness, grain size and ELA energy density, a‐Si thickness. The correlations between LTPS roughness, grain size and Vth shift were also demonstrated, which is very valuable for the research of PMOS hysteresis effect.