| 摘要 |
PURPOSE:To enable measurement in a fine area along with a higher measuring accuracy, by phase detection of a signal as obtained by amplifying the current generated from photoelectrons released from the surface of a sample. CONSTITUTION:A detecting section 1 houses an ultraviolet ray source 2 and a collector 4 for catching photoelectrons released from the surface of a Si wafer 3. With a Si wafer 3 having a clean surface, current flows to the collector 4 as photoemission current. But when any contamination film exists on the surface of the Si wafer 3, the photoemission current decreases as compared with the Si wafer 3 with a clean surface, thereby enabling the evaluation of contamination of the surface of the Si wafer 3. Furthermore, the phase detection of photoemission current amplified with a preamplifier 8 is performed with a lock-in amplifier 9 using a signal wave generated from a pulse generator 6 as reference wave to permit highly sensitive measurement with decrease in the effect of noise. This enables decrease in the quantity of light of an ultraviolet ray source or the like, thereby assuring accurate measurement in a fine area. |
