This study examines the effect of etching modes and their combination on the design, microstructure and optical properties of compliant substrates based on porous silicon. Data obtained from microstructural and spectroscopic methods of analysis showed that, under invariable parameters of the crystal lattice, the value of residual stresses, size of the crystallites, volume of crystalline fraction, and the reflectivity and energy of direct transitions in the porous layer of silicon all depend on the combination of the etching modes. However, they do not always correlate with the value of the layer porosity calculated from an analysis of SEM images. Competent selection of these parameters can provide additional advantages in case of monolithic integration of A_IIIB_V layers and the obtained compliant silicon substrate. Proper selection also ensures an efficient solution to problems concerning the control of deformation and residual stresses in the epitaxial layer. As an outcome, this will open up new methods of design and development for effective devices related to silicon-based electronics.