not able to withstand the hydrodynamic pressure exerted by the hydrogen molecules this results in horizontal cracks 26 in the layer the presence of sufficient horizontal cracks results in the separation of the layer from the substrate the layer can then detach from the substrate as shown in fig5 g and h for the case of 25 hf solution and 150 ma cm 2 current density the separation of the psl occurs at around 45 55 seconds because of the high current density reaction occurs very fast the centre portion of the layer gets detached with the wafer but the periphery remains attached with the silicon because of the construction of the experimental set up therefore after the formation of separation layer if the reaction is allowed to continue the by product hydrogen gathers underneath the layer and exerts pressure on the film the film breaks because of this pressure therefore exact control of the reaction is required in another approach which comprises two steps one can exploit the use of electro polishing together with the electrochemical etching for the formation of separation layer for the purpose of this invention polishing shall be understood as etching a rough surface such that the uneven topography of the surface decreases.