  We consider a model of self-avoiding walk on a lattice with on-site repulsion
and an attraction for every vertex of the walk visited on the surface to study
force-induced desorption of a linear polymer chain adsorbed on an attractive
surface and use the exact enumeration technique for analyzing how the critical
force for desorption $f_c(T)$ depends on the temperature. The curve $f_c(T)$
gives the boundary separating the adsorbed phase from the desorbed phase. Our
results show that in two dimensions where surface is a line the force $f_c(T)$
increases monotonically as temperature is lowered and becomes almost constant
at very low temperatures. In case of three-dimensions we, however, find
re-entrance, i. e. $f_c(T)$ goes through a maximum as temperature is lowered.
The behaviour of the polymer chain at different values of temperature and force
is examined by calculating the probability distribution of the height from the
surface of the vertex at which external force is applied.
