Temperature dependence of the surface thickness parameter b in the original version of proximity formalism is investigated by including the modification effects of equation of state (EOS) at finite temperature on nuclear potential. Here, this modification is performed using the evaluation of the increasing of total energy in the overlapping region by the EOS extracted from the extended Thomas-Fermi approach for asymmetric nuclear matter at finite temperature. This EOS is also supplemented with the saturation effects of nuclear matter density. Our results show a different temperature dependence for surface thickness b of the excited compound nucleus, which is formed during the fusion process. The original version of Proximity 77 with this new form of b(T ) provides a reasonable result for theoretical values of the barrier characteristics and fusion cross section. Our obtained results are also compared with other theoretical approaches.
