Formation of porous structures in GaN/SiC heterostructures in light of the need for porous templates for improved GaN epitaxial growth has been studied. It has been observed that the built-in stress in the heterostructures greatly affects the process of porous structure formation. As a result, it is shown that two major issues are necessary to consider when fabricating a porous GaN/SiC template: firstly, the initial heterostructures must be selected according to the built-in stress value, and secondly, anodization parameters necessary to achieve a homogeneous porous structure must be used. Having considered these, we achieved 30% stress reduction in 2” GaN/SiC templates. Improvements of GaN growth result from employing porous templates and have been shown to depend on growth conditions.