In this work, we present a methodology which enables to optimize the composition x of (AIN)(x)(SiC)(1-x) buried layers implanted in 6H-SiC host material. Our approach is based on the elasticity theory of strained interfaces which successfully predicts the formation of stable phases induced by epitaxial strains as well as their composition. In the investigated system, the two parent materials of the (AIN)(x)(SiC)(1-x) solid solution are AIN and SiC. The used elastic properties of these two host materials take account of the specific implantation method as a perturbative method inducing local modifications into the SiC matrix. The optimization procedure involves fitting of two parameters associated with the (AIN)(x)(SiC)(1-x)/6H-SiC interface structure, namely (i) the elastic-constant, density-related parameter S and (ii) the geometric parameter n(S). When these parameters fulfill continuity and inter-phase pseudomorphism conditions, respectively, an optimal composition is determined, in agreement with experimental results.