Method for manufacturing dual FinFET device

A method for manufacturing a semiconductor device, the method comprising:

• providing a substrate comprising a first region and a second region;
• forming a hard mask on the first region of the substrate;
• forming a mask layer on the second region of the substrate;
• recessing the substrate by using the hard mask and the mask layer to form a first raised structure in the first region and a second raised structure in the second region;
• forming a plurality of first isolation structures and two second isolation structures, wherein forming the plurality of first isolation structures comprises removing portions of the first raised structure to form at least two fin structures which extend along a direction, wherein lower portions of two opposite sidewalls of each of the at least two fin structures are covered by two of the plurality of first isolation structures, and two opposite sidewalls of the second raised structure are completely covered by the two second isolation structures;
• forming a first gate structure extending on first portions of the at least two fin structures and portions of the plurality of first isolation structures, and a second gate structure extending on a first portion of the second raised structure and portions of the two second isolation structures, wherein the first gate structure covers upper portions of the two opposite sidewalls and top surfaces of the first portions of the at least two fin structures;
• and
• forming a first source and a first drain respectively on two opposite sides of the first gate structure on the at least two fin structures, and a second source and a second drain respectively on two opposite sides of the second gate structure in the second raised structure.

A method for manufacturing a semiconductor device, the method comprising:

• providing a substrate comprising a first region and a second region;
• recessing the substrate by using a hard mask and a mask layer to form a first raised structure in the first region and a second raised structure in the second region, wherein the hard mask is formed on the first region on a sidewall of at least one fin mandrel, and the mask layer is formed on the second region;
• forming two first isolation structures and two second isolation structures respectively covering two opposite sidewalls of the second raised structure, wherein forming the two first isolation structures comprises removing portions of the first raised structure to form a fin structure, wherein lower portions of two opposite sidewalls of the fin structure are respectively covered by the two first isolation structures;
• forming a first gate structure extending on a first portion of the fin structure and portions of the two first isolation structures, and a second gate structure extending on a first portion of the second raised structure and portions of the two second isolation structures, wherein the first gate structure covers upper portions of the two opposite sidewalls and a top surface of the first portion of the fin structure;
• and
• forming a first source and a first drain respectively on two opposite sides of the first gate structure on the fin structure, and a second source and a second drain respectively on two opposite sides of the second gate structure in the second raised structure.