An integrated circuit (IC) structure includes a substrate and a fin structure. The substrate includes a first cell region and a second cell region abutting the first cell region. The fin structure includes a first plan-view profile within the first cell region and a second plan-view profile within the second cell region. The first plan-view profile includes a first sidewall and a second sidewall opposing the first sidewall. The second plan-view profile includes a third sidewall and a fourth sidewall opposing the third sidewall. A width between the first sidewall and the second sidewall is greater than a width between the third sidewall and the fourth sidewall.