Ultra-thin self-supporting silicon membrane and associated manufacturing process

Abstract

The invention relates to a method for manufacturing a self-supporting monocrystalline silicon membrane, comprising the following steps: a) supplying a monocrystalline silicon donor substrate, the front face of which extends along a principal plane and has at least one lateral dimension greater than or equal to 50 mm, b) forming, by ion implantation of hydrogen and helium in the donor substrate, with doses between 1E16 H / cm2 and 5E16 H / cm2 and between 2E16 He / cm2 and 1E17 He / cm2 respectively, a buried brittle plane, parallel to the principal plane, defining with the front face of the donor substrate, a surface layer of thickness less than 2 μm, c) applying a separation heat treatment to the donor substrate to propagate a fracture wave in the buried brittle plane and separate the surface layer from the donor substrate, the front face of the donor substrate not being attached to any stiffener.Step c) is carried out such that a displacement of the surface layer, perpendicular to the principal plane, exceeding 200 μm, is prevented during the propagation of the fracture wave, said displacement being prevented at least at a peripheral edge of the surface layer. At the end of step c), a self-supporting membrane corresponding to the separated surface layer is formed, having a thickness of less than 2 μm and at least one lateral dimension greater than or equal to 50 mm. The invention also relates to said self-supporting membrane. Figure to be published with the abstract: No figure.