Semiconductor device and method of inspecting a semiconductor device
View Patent ↗Provided is a semiconductor device including a MOS analog circuit which has a high reliability and a low manufacturing cost, and in which latent failure is easily detected. The MOS analog circuit is switched to a test state or an operating state based on a control signal that is externally supplied. In the test state, a voltage between a power supply terminal and a reference terminal is applied to a gate oxide film of a MOS transistor included in the MOS analog circuit.
1. A semiconductor device, comprising:
a MOS analog circuit comprising a MOS transistor; and
a power supply terminal and a reference terminal for supplying a voltage to the MOS analog circuit,
wherein the MOS analog circuit is configured to switch to one of a test state and an operating state based on a control signal that is externally supplied, and
wherein, in the test state, a current path formed, when the MOS transistor is turned on, between the power supply terminal and the reference terminal is blocked, and a voltage between the power supply terminal and the reference terminal is applied to a gate oxide film of the MOS transistor.
2. A semiconductor device according to claim 1 ,
wherein the MOS analog circuit further comprises:
a switching circuit; and
a constant current source,
wherein, in the test state, a drain terminal of the MOS transistor is placed in an open state when the switching circuit is turned off, and
wherein, in the operating state, a current based on an output current of the constant current source is supplied to the drain terminal of the MOS transistor when the switching circuit is turned on.
3. A method of inspecting a semiconductor device,
the semiconductor device comprising:
a MOS analog circuit comprising a MOS transistor; and
a power supply terminal and a reference terminal for supplying a voltage to the MOS analog circuit,
the method comprising:
switching, based on a control signal that is externally supplied, the MOS analog circuit to a test state in which a current path formed, when the MOS transistor is turned on, between the power supply terminal and the reference terminal is blocked, and a voltage between the power supply terminal and the reference terminal is applied to a gate oxide film of the MOS transistor;
measuring a current flowing between the power supply terminal and the reference terminal; and
detecting failure of the semiconductor device.