Optimization of Reaction Conditions in a Fluidized‐Bed for Silane Pyrolysis

Abstract

The fluidized‐bed chemical vapor deposition (CVD) process for polycrystalline silicon production is considered to be the most attractive alternative to the conventional bell‐jar process. In order to obtain stable operation, high space‐time‐yields and high purity of the product several obstacles have to be eliminated. Reaction conditions must be optimized to avoid the homogeneous decomposition of silane and minimize silicon dust formation. The effect of temperature, silane partial pressure, gas velocity and the size of bed particles has to be identified. These dependencies and the interaction between hydrodynamics and kinetics of homogeneous and heterogeneous CVD‐reactions were studied in a laboratory‐scale fluidized‐bed reactor.

Manufacture of Granular Polysilicon from Trichlorosilane in a Fluidized‐Bed Reactor

“…The cross section of the final particles confirmed that the adding of fine silicon dust onto large seed particles significantly contributed to the particle growth [27]. In literature it is described that the surface of the product from silane pyrolysis was not as monolithic as the seed particles because the dust particles attached caused a rough surface of the grains.…”

Multifluid Eulerian modelling of a silicon Fluidized Bed Chemical Vapor Deposition process: Analysis of various kinetic models

“…This development explains the significant increase in the demand for solar grade (SG) silicon since polycrystalline silicon based solar cells are the predominant solar cell technology [2].…”

Hydrogen Terminated Silicon Nanopowders: Gas Phase Synthesis, Oxidation Behaviour, and Si-H Reactivity

“…The chemical behaviour of silicon surfaces and interfaces have, therefore, been investigated extensively [1,2]. Nanocrystalline silicon (nc-Si) powders were synthesised by thermal decomposition of monosilane in a hot wall reactor [3] or a fluidized bed reactor [4][5][6] and gas phase deposition (CVD or CVS). Alternatively, the hot-wire (HW) technology was advantageous due to its high deposition rates, efficient source gas utilization, lack of ion bombardment, and low equipment cost.…”