| 摘要 |
PURPOSE:To obtain the distribution of traps precisely by measuring flat band voltage as a semiconductor wafer is left as it is fixed to an electrode, a relative position thereof with a mercury electrode is fixed, while etching an insulating film as the electrode is left as it is fastened to the back of the semiconductor wafer. CONSTITUTION:The back of a semiconductor substrate 3 to which a MOS capacitor 7 is formed is bonded and fixed to a metallic layer 21 by using conductive adhesives 21a. An electrode for the MOS capacitor and a mercury electrode 8 are positioned, pulse voltage is applied, and electrons are injected to an SiO2 film 2 just under the electrode from the Si substrate 3 and electrons are capsured by electron traps. Capacitance-voltage are measured, and flat band voltage VFB is acquired. The predetermined thickness of the Al electrode and the SiO2 film 2 is etched by employing hydrofluoric acid. The flat bond voltage VFB of the SiO2 film in which electrons are trapped by using a mercury prober 12 is obtained. Etching and flat band voltage VFB are repeated. Accordingly, mercury can be struck against the same position of a semiconductor wafer at all times, thus accurately acquiring the distribution of the traps. |
