| 摘要 |
PURPOSE:To make it possible to measure the carrier concentration of semiconductor highly accurately, by externally detecting the AC component of a current, when an electron beam, which undergoes luminance modulation by an AC signal, flows across a depletion layer in the semiconductor. CONSTITUTION:On a sample stage 5 of an electron microscope 1, a semiconductor 6, in which a P-N junction or Schottky junction is formed, is mounted. An electron beam 3, whose intensity is modulated by an AC signal from an electron-beam modulating circuit 4, is projected. A current flows across a depletion layer of the semiconductor 6 owing to the electron beam 3. The AC component of the current is detected and amplified by an amplifier 7 having square- law characteristics. The output is supplied to a display device 8, and the carrier concentration of the semiconductor 6 at the projected position of the electron beam 3 is displayed. |
