An integrated circuit (IC) device includes a circuit region including an active region along a first axis and a gate region along a second axis transverse to the first axis, and a clock distribution system configured to supply a clock signal to the circuit region. The clock distribution system includes, in a first metal layer over the circuit region, a plurality of first metal patterns oblique to both the first axis and the second axis. The clock distribution system further includes, in a second metal layer over the circuit region, a plurality of second metal patterns transverse to the plurality of first metal patterns and oblique to both the first axis and the second axis. The plurality of first metal patterns in the first metal layer includes at least one clock spine having a greater width than other first metal patterns among the plurality of first metal patterns.