Patent ID: 8466028
Filing Date: 2013-06-18
Classification: H01L

Abstract:
1. A method for manufacturing a multigate device, comprising: providing a semiconductor substrate; etching the semiconductor substrate to form a protruding fin; etching the semiconductor substrate at the bottom of the fin so as to form a gap between the fin and the semiconductor substrate; forming a dielectric layer which covers the semiconductor substrate and the fin and fills the gap; and etching the dielectric layer so as to expose the top and a portion of sidewalls of the fin; wherein, the protruding fin is formed by anisotropic etching, during which reaction a polymer is formed; and the step of etching the semiconductor substrate at the bottom of the fin so as to form a gap between the fin and the semiconductor substrate comprises: etching the semiconductor substrate at the bottom of the fin by isotropic etching and using the polymer formed from the anisotropic etching as a mask, so as to form a gap between the fin and the semiconductor substrate.