COMPARISON OF THE STRESS BETWEEN RAPID THERMAL ANNEALED AND EXCIMER-LASER ANNEALED POLYCRYSTALLINE SILICON THIN-FILMS

Characteristics of polycrystalline silicon films with large substrate such as 50 mm x 50 mm, crystallized by using furnace annealing (FA), m ulti-step rapid thermal annealing (MSRTA) and excimer laser annealing (ELA) methods, have been investigated. In order to characterize the re sidual stress in crystalline silicon on coming 7059 glass, polarized R aman spectroscopy were measured for those various annealing methods an d at various substrate temperatures. We observed that the polycrystall ine Si films, crystallized by ELA, have a high crystalline volume frac tion, residual stress and equiaxial crystal growth. On the other hand, silicon films crystallized by FA and MSRTA have a low compressive str ess and dendritic structure, which are due to thermal relaxation. Thes e Si films have a broad hump around 480 cm(-1) which indicates the exi stence of amorphous phase silicon. The magnitudes of stresses of FA an d MSRTA are 4.07 x 10(9) and 4.46 x 10(9) dyne cm(-2), respectively an d the magnitude stress of laser annealing decreases from 1.35 x 10(10) to 8.58 x 10(9) dyne cm(-2) with increasing the substrate temperature from room temperature to 400 degrees C. (C) 1998 Elsevier Science Ltd .