Integrated circuits (IC) are provided. An IC includes a plurality of macros and a top channel. Each macro includes a macro boundary and a main pattern surrounded by the macro boundary. The top channel includes a plurality of first and second sub-channels. Each first sub-channel is arranged between a first macro and a second macro, and is formed by a plurality of first dummy boundary cells. Each second sub-channel is arranged between two of the second macros, and is formed by a plurality of second dummy boundary cells. The macro boundaries of the first macros are formed by the first dummy boundary cells, and the macro boundaries of the second macros are formed by the second dummy boundary cells. A first gate length of dummy patterns within the first dummy boundary cells is greater than a second gate length of dummy patterns within the second dummy boundary cells.