The invention pertains to formation of a semiconducting portion (60) by epitaxial growth on a strained germination portion (40), comprising the steps in which a cavity (21) is produced under a structured part (11) by rendering free a support layer (30) situated facing the structured part (11), a central portion (40), termed the strained germination portion, then being strained; and a semiconducting portion (60) is formed by epitaxial growth on the strained germination portion (40), wherein the structured part (11) is furthermore placed in contact with the support layer (30) in such a way as to bind the structured part (11) of the support layer.

A cyclic deposition and etch method is provided. The method includes depositing an epitaxial layer over a substrate at a first temperature and etching a portion of the deposited epitaxial layer at a variable temperature higher than the first temperature. The step of etching is performed while varying the temperature.