This paper successfully used inclined exposure technology to fabricate $45°$ polymer optical grade micromirrors ( $\sim 1.4\mathrm{mm}$ thick) while applying the surface free energy minimization principle to improve sidewall indentation. This paper tests the effect of the reflow process on the surface roughness of inclined surfaces. Experimental results are considered in light of the theory of minimizing free energy. The smallest surface roughness achieved in the experiments using SU-8 material with a thickness of $1.4\mathrm{mm}$ was less than $20\mathrm{nm}$ . The effect of the reflow process on the surface indentation of inclined microstructures showed that the 1D WYKO profile of maximum height fell from $0.81\mathrm{\mu m}$ to $0.08\mathrm{\mu m}$ ( R_t ), which is an improvement of 90% after the reflow process. This type of micromirror can be used as a key component in Blu-Ray optical pickup heads used in portable, high-density storage systems.