Preparation of High-Quality Microcrystalline Silicon from Fluorinated Precursors by a Layer-by-Layer Technique

Abstract

Microcrystalline silicon thin films exhibiting high crystallinity and high quality were successfully fabricated from the fluorinated precursors SiH n F m (n+m≤3) by repeating the deposition of very thin layers, 10 nm thick, and by treatment with atomic hydrogen. Hydrogen concomitant with dangling bonds is efficiently removed from the Si network at the levels of 0.45 at.% and 3.7×1016 spins/cm3, respectively. A specific texture showing a strong orientation toward (220) is observed in the X-ray diffraction (XRD) spectra. High photoconductivity and a considerable diffusion length of 400 nm for holes under the ambipolar condition verify the films' high quality and high crystallinity.

Hydrogenated nanocrystalline silicon thin film prepared by RF-PECVD at high pressure

“…This work accelerated the development of nc-Si:H technology, due to its potential applications in optoelectronic devices including light emitting diodes, optical memories, tunneling diodes, thin film transistors, single electron transistors, and especially thin film solar cells for its low optical absorption, high carrier mobility and high doping efficiency compared with their amorphous counterparts. Also, because of its more ordered structure, nc-Si could provide better stability against light induced degradation [4,5]. Silicon solar cells made of entirely nanocrystalline material with marked improvement in the near-infrared absorption of the solar spectrum and in possible absence of light induced degradation have also been reported [6].…”

In situ real time studies of the formation of polycrystalline silicon films on glass grown by a layer-by-layer technique

“…4 Thick poly-Si films ͑ϳ1 m͒ with high crystalline content were built up by the layerby-layer ͑LBL͒ technique. 5 The poly-Si thin films fabricated by the LBL technique exhibit a highly textured structure with grain sizes more than 0.2 m. 5 The films also have a high Hall mobility of electrons despite a low fabrication temperature around 300°C. 6 Some elements of the growth process by the HR-CVD have been studied by means of real-time ellipsometry measurements.…”

“…In our previous study, the optimal thickness was 10 nm. 5 This evidence suggests that there is an optimal thickness of the subsurface for atomic hydrogen stimulation of the structural relaxation, which is determined by preparation conditions such as substrate temperature, deposition rate, atomic hydrogen flux, etc.…”

Control of Grain Size and Texture of Poly-Si with Atomic Hydrogen Under In Situ Ellipsometric Observation

“…[6] Both monovalent elements, H and F, remaining in the amorphous tissue were reduced to the levels, <1.5x10 20 and < 5x10 19 cm-3 , respectively, as a result of the formation of the secondary ordered structure. [6] Both monovalent elements, H and F, remaining in the amorphous tissue were reduced to the levels, <1.5x10 20 and < 5x10 19 cm-3 , respectively, as a result of the formation of the secondary ordered structure.…”