Structure and method for providing line end extensions for fin-type active regions

A semiconductor structure, comprising:

• a semiconductor substrate;
• a first fin-like active region protruding from a surface of the semiconductor substrate and extending horizontally in a first direction, the first fin-like active region having a first end portion;
• a second fin-like active region protruding from the surface of the semiconductor substrate and extending horizontally in the first direction and collinear with the first fin-like active region, the second fin-like active region having a second end portion;
• a shallow trench isolation feature disposed at a location between the first fin-like active region and the second fin-like active region, the shallow trench isolation feature being in direct contact with the first end portion and the second end portion;
• and
• a first functional structure, a second functional structure and a dummy structure, each comprising a main portion and two sidewall spacer elements disposed on opposite sidewalls of the respective main portions;
• wherein the main portion of the first functional structure is a transistor gate electrode of a first field-effect transistor, the first field-effect transistor further comprising a first source/drain feature and a second source/drain feature formed in the first fin-like active region at opposite sides of the first functional structure, the second source/drain feature being adjacent to the first end portion;
• and
• wherein the main portion of the second transistor gate electrode is a transistor gate electrode of a second field-effect transistor, the second field-effect transistor further comprising a third source/drain feature and a fourth source/drain feature formed in the second fin-like active region at opposite sides of the second functional structure, the third source/drain feature being adjacent to the second end portion;
• wherein the main portion of the dummy structure overlies the shallow trench isolation, and the two sidewall spacer elements of the dummy structure include a first sidewall spacer element and a second sidewall spacer element, the first sidewall spacer element overlying the first end portion, and the second sidewall spacer element overlying the second end portion;
• wherein the first and the second source/drain features comprise epitaxial regions, and the third and the fourth source/drain features comprise epitaxial regions;
• wherein the epitaxial regions of the first and second source/drain features are spaced from the shallow trench isolation feature;
• wherein the first fin-like active region is one of a first plurality of fin-like active regions, and the second fin-like active region is one of a second plurality of fin-like active regions;
• wherein the first plurality of fin-like active regions are parallel to each other in a second direction perpendicular to the first direction, and the second plurality of fin-like active regions are parallel to each other in the second direction;
• wherein the shallow trench isolation feature extends in the second direction between the first plurality of fin-like active regions and the second plurality of fin-like active regions;
• wherein the first functional structure extends over each of the first plurality of fin-like active regions;
• wherein the second functional structure extends over each of the second plurality of fin-like active regions;
• wherein the first sidewall spacer extends over end portions of each of the first plurality of fin-like active regions;
• and wherein the second sidewall spacer element extends over end portions each of the second plurality of fin-like active regions.