Isolation structure of fin field effect transistor

摘要

The disclosure relates to a fin field effect transistor (FinFET). An exemplary FinFET comprises a substrate comprising a major surface; a fin structure protruding from the major surface comprising a lower portion comprising a first semiconductor material having a first lattice constant; an upper portion comprising the first semiconductor material, wherein a bottom portion of the upper portion comprises a dopant with a first peak concentration; a middle portion between the lower portion and upper portion, wherein the middle portion comprises a second semiconductor material having a second lattice constant different from the first lattice constant; and an isolation structure surrounding the fin structure, wherein a portion of the isolation structure adjacent to the bottom portion of the upper portion comprises the dopant with a second peak concentration equal to or greater than the first peak concentration.

主权项

1. A fin field effect transistor (FinFET) comprising:
a substrate comprising a major surface; a fin structure protruding from the major surface, the fin structure comprising:
a lower portion comprising a first semiconductor material having a first lattice constant;an upper portion comprising the first semiconductor material, wherein a bottom portion of the upper portion comprises a dopant with a first peak concentration; anda middle portion between the lower portion and upper portion, wherein the middle portion comprises a second semiconductor material having a second lattice constant different from the first lattice constant; and an isolation structure adjacent to the fin structure; wherein:
a first region of the isolation structure laterally adjacent to the bottom portion of the upper portion comprises the dopant with a second peak concentration equal to or greater than the first peak concentration;a second region of the isolation structure laterally adjacent to a bottom portion of the middle portion, the second region comprising the dopant with a third peak concentration equal to or greater than the first peak concentration; anda third region of the isolation structure laterally adjacent to a portion of the upper portion above the bottom portion of the upper portion, the third region comprising the dopant with a fourth peak concentration equal to or greater than the first peak concentration.