Temperature dependence of resistivity $\rho \left(T\right)$ of semiconductors, insulators and metals is significantly based on the following factors

The resistivity of a metallic conductor is given by,
$e=\frac{m}{n{e}^2\tau }$
where, n is number of charge carriers per unit volume which can change with temperature T and $\tau$ is time interval between two successive collisions which decreases with the increase of temperature.