It has been recently shown that manufacturing of an implanted-junction rectifier in a semiconductor heterostructure for optimal relationship between energy of implanted ions, materials and thicknesses of layers of the heterostructure (H) after annealing of radiation defects gives us possibility to increase sharpness of p-n-junction and at the same time to increasing of homogeneity of dopant distribution in the doped area (Pankratov, Phys Lett A 372(11):1897, 2008 Proc SPIE 7521:75211D, 2010a, b). In this paper we consider a possibility to decrease quantity of radiation defects, which were generated during ion implantation, using porous epitaxial layers of the heterostructure.