Provided is a semiconductor chip to generate an identification key. The semiconductor chip may include a first inverter having a first logic threshold, a second inverter having a second logic threshold, and a first switch. The first switch may include a first terminal and a second terminal, and may short or open a connection between the first terminal and the second terminal according to an first input voltage value. An input terminal of the first inverter, an output terminal, and the first terminal of the first switch may be connected to a first node. An output terminal of the first inverter, an input terminal of the second inverter, and the second terminal of the first switch may be connected to a second node.