A method for manufacturing a semiconductor structure comprising clusters and/or nanocrystals of silicon described which are present in distributed form in a matrix of silicon compound. The method comprises the steps of depositing a layer of thermally nonstable silicon compound having a layer thickness in the range between 0.5 nm and 20 nm especially between 1 nm and 10 nm and in particular between 1 nm and 7 nm on a support and thermal treatment at a temperature sufficient to carry out a phase separation to obtain clusters or nanocrystals of silicon in a matrix of thermally stable silicon compound. The claims also cover semiconductor structures having such distributed clusters or nanocrystals of silicon The method described enables the economic production of high density arrays of silicon clusters or nanocrystals with a narrow size distribution.