Various embodiments include approaches for predicting unity gain frequency in a MOSFET. In some cases, a method includes predicting a unity gain frequency (f.sub.T) in a MOSFET device in a manufacturing line, the method including: measuring a first set of in-line direct current (DC) parameters of the MOSFET on the manufacturing line at a first drain voltage (V.sub.d1); extracting a transconductance (G.sub.m) from the first set of in-line DC parameters as a function of a gate-voltage (V.sub.g) and the first drain-voltage (V.sub.d1); measuring a second set of in-line DC parameters of the MOSFET on the manufacturing line at a second drain voltage (V.sub.d2); extracting a total gate capacitance (C.sub.gg) from the second set of in-line DC parameters as a function of the gate-voltage (V.sub.g); and predicting the unity gain frequency (f.sub.T) of the MOSFET based upon the extracted transconductance (G.sub.m) and the extracted total gate capacitance (C.sub.gg).

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.

Provided is a method of determining a gate capacitance of a semiconductor device having a source, a drain, a gate, and a channel, the semiconductor device being arranged in a circuit further comprising an electrical resonator, wherein one of the source, the drain, and the gate is connected to the electrical resonator. The method comprises: measuring a resonance frequency of the circuit; and calculating, based on the resonance frequency, the gate capacitance. Since it is not necessary to pass a current through the semiconductor device, an accurate measurement of gate capacitance may be achieved. Also provided are an apparatus for determining a gate capacitance, a probe for measuring gate capacitance, and a related computer program product.