ELECTRON MICROSCOPE AND FOCUS ADJUSTMENT METHOD THEREOF

• Main Authors: TANIMOTO NORIFUMI, OHASHI KENYOSHI, KIN KEISHIN, ABE YUSUKE
• Format: Patent
• Language: English; Japanese
• Published: 13.12.2021
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRICITY

To reduce a time required to adjust the focus of an electron microscope at a plurality of inspection points.SOLUTION: When the focus is adjusted according to the height of the surface of a sample at each inspection point in order to continuously inspect a plurality of inspection points on a wafer using an electron microscope, even when the variation in the height of the inspection points is larger than a predetermined range, and it is necessary to use both focus adjustment with a high-speed adjustable electrostatic lens and adjustment with a low-speed electromagnetic lens, a focus adjustment flow that reduces the number of adjustments by the electromagnetic lens by using a relationship between the height change of an inspection point, the inspection order, and an electrostatic focusable range has been realized, enabling high-throughput inspection.SELECTED DRAWING: Figure 6 【課題】複数の検査箇所で電子顕微鏡のフォーカス調整に要する時間を短縮する。【解決手段】電子顕微鏡を用いてウエハ上の複数の検査箇所を連続して検査するために各検査箇所で試料の表面の高さに応じてフォーカス調整を行う際、検査箇所の高さのばらつきが所定の範囲より大きく、高速に調整可能な静電レンズによるフォーカス調整と低速な電磁レンズによる調整を併用する必要がある場合にも、検査箇所の高さの変化、検査順序、および静電フォーカス可能な範囲の関係を用いて電磁レンズによる調整の回数を低減したフォーカス調整のフローを実現し、高スループットな検査を可能にした。【選択図】図６