  Lattice models are useful for understanding behaviors of interacting complex
many-body systems. The lattice dimer model has been proposed to study the
adsorption of diatomic molecules on a substrate. Here we analyze the partition
function of the dimer model on an $2 M \times 2 N$ checkerboard lattice wrapped
on a torus and derive the exact asymptotic expansion of the logarithm of the
partition function. We find that the internal energy at the critical point is
equal to zero. We also derive the exact finite-size corrections for the free
energy, the internal energy, and the specific heat. Using the exact partition
function and finite-size corrections for the dimer model on finite checkerboard
lattice we obtain finite-size scaling functions for the free energy, the
internal energy, and the specific heat of the dimer model. We investigate the
properties of the specific heat near the critical point and find that
specific-heat pseudocritical point coincides with the critical point of the
thermodynamic limit, which means that the specific-heat shift exponent
$\lambda$ is equal to $\infty$. We have also considered the limit $N \to
\infty$ for which we obtain the expansion of the free energy for the dimer
model on the infinitely long cylinder. From a finite-size analysis we have
found that two conformal field theories with the central charges $c = 1$ for
the height function description and $c = -2$ for the construction using a
mapping of spanning trees can be used to describe the dimer model on the
checkerboard lattice.
