A fin-type field effect transistor comprising a substrate, at least one gate structure, spacers and strained source and drain regions is described. The at least one gate structure is disposed over the substrate and on the isolation structures. The spacers are disposed on sidewalls of the at least one gate structure. First blocking material layers are disposed on the spacers. The strained source and drain regions are disposed at two opposite sides of the at least one gate structure. Second blocking material layers are disposed on the strained source and drain regions. The first and second blocking material layers comprise oxygen-rich oxide materials.