“Pop-out” effect in silicon is a large studied phenomenon, which have been considered and analyzed in many articles [1-3]. The revelation of this effect is inseparably linked with appearance of the dynamic methods of the material indentation, where the depth of the indenter penetration is continuously measured in dependence on the applied load. In this work the “pop-out” effect was studied in the ITO/Si and SnO2/Si composite structures, and in the silicon crystals doped with phosphorus, used as a substrate for above mentioned structures.FIGUREFig. Correlation between indenter deepening (hmax) (a) and depth of “pop-out” appearance (hpop-out) (b) for ITO/Si, SnO2/Si composite structures and Si substrate with maximal load (Pmax) applied to indenter The fulfilled research revealed a characteristic peculiarity: the value of the K=Ppop-out/Pmax coefficient at the first stage (Pmax ≤100 mN) was less than at the second stage for the all studied materials. It confirms the existence of more high internal stresses on second stage, which lead to more sharp increase of the indenter penetration depth in material, activation of the relaxation processes at an earlier stage of unloading und, accordingly, to changing of the curve slope angle Pmax(hmax) and Pmax(hpop-out) (Fig.). Thereby, for investigated materials (ITO/Si and SnO2/Si structures, Si substrate), follow regularity was detected: the appearance of “pop-out” effect essentially depends on the Pmax value and weaker depends on the unloading velocity. It is a definite loading interval (40-400 mN) where the “pop-out” effect appears with a greater probability. [1]. G.M. Pharr, W.C. Oliver, D.R. Clarke. J. of Electronic Mat., 1990, v. 19, nr.9, 881-887 [2]. J.E. Bradby, J.S. Williams, J. Wong-Leung, M.V. Swain, P. Munroe. Appl. Phys. Lett., 2000, v. 77, 3749-3751 [3]. I. Zarudi, L.C. Zhang, W.C.D. Cheong, T.X. Yu. Acta Mater., 2005, v. 53, 4795-4800