Patent ID: 7863922

Claim:
An insulating film evaluation method, employing a measurement circuit which comprises: a first MOS diode including: a first diffusion layer formed on a semiconductor substrate of one conductivity type and having an opposite conductivity type, a first insulating film formed on the first diffusion layer, and a first electrode formed on the first insulating film; a second MOS diode including: a second diffusion layer formed close to the first diffusion layer, a second insulating film formed on the second diffusion layer, and a second electrode formed on the second insulating film; a first terminal connected to the first electrode and the second diffusion layer; a second terminal connected to the second electrode and the first diffusion layer; a current source interposed between the first terminal and the second terminal; and a voltmeter placed in parallel to the current source, the insulating film evaluation method comprising: applying an electric current flow in one direction between the first terminal and the second terminal to measure a change in voltage between the terminals.