Fin structure of FinFET

摘要

A fin structure disposed over a substrate and a method of forming a fin structure are disclosed. The fin structure includes a mesa, a channel disposed over the mesa, and a convex-shaped feature disposed between the channel and the mesa. The mesa has a first semiconductor material, and the channel has a second semiconductor material different from the first semiconductor material. The convex-shaped feature is stepped-shaped, stair-shaped, or ladder-shaped. The convex-shaped feature includes a first isolation feature disposed between the channel and the mesa, and a second isolation feature disposed between the channel and the first isolation feature. The first isolation feature is U-shaped, and the second isolation feature is rectangular-shaped. A portion of the second isolation feature is surrounded by the channel and another portion of the second isolation feature is surrounded by the first isolation feature.

主权项

1. A fin structure, comprising:
a mesa having a first semiconductor material, the mesa having a height, a length and width, where the length is greater than the width; a first isolation feature formed in and extending above the mesa, the first isolation feature having a width substantially equal to the width of the mesa; a channel disposed over the first isolation feature, wherein the channel has a second semiconductor material different from the first semiconductor material; and a second isolation feature disposed in the first isolation feature, the second isolation feature having a width less than the width of the first isolation feature and extending above the first isolation feature, wherein the channel extends from a side of the second isolation feature, over the top of the second isolation feature and onto the other side of the second isolation feature.