Method for separating at least two substrates along a selected interface

A process for separating at least two substrates forming part of a structure comprising at least two separation interfaces extending parallel to main faces of the structure, along one interface selected from the at least two separation interfaces, at least one of the two substrates being intended to be used in electronics, optics, optoelectronics and/or photovoltaics, the separation of the at least two substrates being carried out by inserting a blade between the at least two substrates and applying a parting force, via the blade, and at least partially parting the at least two substrates, the method comprising:

• before inserting the blade into an insertion region between the at least two substrates, damaging at least one portion of a peripheral region of the one interface in the insertion region such that a rupture energy in the at least one portion of the peripheral region is lower than a rupture energy of other interfaces of the at least two separation interfaces in the insertion region;
• inserting the blade into the insertion region between the at least two substrates and applying a parting force, via the blade, and partially parting the at least two substrates along the one interface in the damaged region;
• and
• applying a fluid in a space between the partially parted at least two substrates while the blade remains inserted therebetween and decreasing the rupture energy of the one interface by stress corrosion involving breaking of siloxane bonds present at the interface.