Citation

Song O, Choi Y, Han J, Kim G. Journal of Korean Institute of Metals and Materials 2011; 49(4): 321-328.

Copyright

(Copyright © 2011)

DOI

10.3365/KJMM.2011.49.4.321

PMID

unavailable

Abstract

The 30 nm-thick Ni layers was deposited on a flexible polyimide substrate with an e-beam evaporation. Subsequently, we deposited a Si layer using a catalytic CVD (Cat-CVD) in a hydride amorphous silicon (α-Si:H) process of T8=180°C with varying thicknesses of 55, 75, 145, and 220 nm. The sheet resistance, phase, degree of the crystallization, microstructure, composition, and surface roughness were measured by a four-point probe, HRXRD, micro-Raman spectroscopy, FE-SEM, TEM, AES, and SPM. We confirmed that our newly proposed Cat-CVD process simultaneously formed both NiSi and crystallized Si without additional annealing. The NiSi showed low sheet resistance of <13Q/□, while carbon (C) diffused from the substrate led the resistance fluctuation with silicon deposition thickness. HRXRD and micro-Raman analysis also supported the existence of NiSi and crystallized (>66%) Si layers. TEM analysis showed uniform NiSi and silicon layers, and the thickness of the NiSi increased as Si deposition time increased. Based on the AES depth profiling, we confirmed that the carbon from the polyimide substrate diffused into the NiSi and Si layers during the Cat-CVD, which caused a pile-up of C at the interface. This carbon diffusion might lessen NiSi formation and increase the resistance of the NiSi.

Language: ko

Keywords

Polycrystalline materials; Sheet resistance; Electric resistance; Polysilicon; Substrates; X ray diffraction analysis; Nickel suicide; Amorphous silicon; Depth profiling; Amorphous materials; Surface roughness; Raman spectroscopy; Cat-CVD; Hydrogenated amorphous silicon; Polycrystalline silicon; Polyimide films; Polyimides; Polymeric films