Investigation on characteristics of millisecond solid-phase crystallized silicon films annealed by atmospheric pressure DC arc discharge micro-thermal-plasma-jet and their application to bottom-gate thin film transistors fabrication

Abstract

Millisecond solid phase crystallization (SPC) of silicon film induced by micro-thermal-plasma-jet is a potential method for small grain bottom-gate thin-film transistors (TFTs). The characteristics of millisecond SPC films under the conditions of scanning speed (v) from 500 to 900 mm s−1 were investigated. The films show good crystalline quality when formed at a slow v. The crystallinity estimated by micro-Raman spectroscopy is 61% when v was 500 mm s−1. Hall effect measurement results indicate that under v at 500 mm s−1, the resistivity is 1.36 × 10−3 Ωcm, the carrier concentration is 3.41 × 1020 cm−3, and the carrier mobility is 12.2 cm2 Vs−1. Millisecond SPC films surface reduce larger than 76% roughness compared to that of the melted film surface. Bottom-gate TFTs fabricated with millisecond SPC film, which annealed under conditions close to melted condition, show high field effect mobility of 28 cm2 Vs−1 and good uniformity.