  Silicon crystal puller (SCP) is a key equipment in silicon wafer manufacture,
which is, in turn, the base material for the most currently used integrated
circuit (IC) chips. With the development of the techniques, the demand for
longer mono-silicon crystal rod with larger diameter is continuously increasing
in order to reduce the manufacture time and the price of the wafer. This demand
calls for larger SCP with increasing height, however, it causes serious swing
phenomenon of the crystal seed. The strong swing of the seed causes difficulty
in the solidification and increases the risk of mono-silicon growth failure.The
main aim of this paper is to analyze the nonlinear dynamics in the FSRL system
of the SCP. A mathematical model for the swing motion of the FSRL system is
derived. The influence of relevant parameters, such as system damping,
excitation amplitude and rotation speed, on the stability and the responses of
the system are analyzed. The stability of the equilibrium, bifurcation and
chaotic motion are demonstrated, which are often observed in practical
situations. Melnikov method is used to derive the possible parameter region
that leads to chaotic motion. Three routes to chaos are identified in the FSRL
system, including period doubling, symmetry-breaking bifurcation and interior
crisis. The work in this paper explains the complex dynamics in the FSRL system
of the SCP, which will be helpful for the SCP designers in order to avoid the
swing phenomenon in the SCP.
