| 摘要 |
PROBLEM TO BE SOLVED: To reduce charge-up on conductive layers when the layers are scanned several times with an electron beam, by using recessed sections formed in the conductive layers as alignment marks. SOLUTION: Alignment marks are composed of notched grooves 101 and 201 formed by exposing surfaces of semiconductor substrates 104 and 204 between conductive layers 11-14 and 21-24 formed on the surfaces of the substrates 104 and 204. The positions of the marks 101 and 201 are specified by detecting quantities of reflected electrons discharged from the substrates 104 and 204 and conductive layers 11-14 and 21-24 by scanning the substrates 104 and 204 and layers 11-14 and 21-24 with an electron beam 202. Since the conductive layers 11-14 and 21-24 have large volume and the contact areas between the layers 11-14 and 21-24 and the substrates 104 and 204 are also large, the electrons reaching the surfaces of the layers 11-14 and 21-24 are efficiently diffused to the layers 11-14 and 21-24 or substrates 104 and 204. Therefore, no charge-up occurs on the conductive layers 11-14 and 21-24 even when the layers 11-14 and 21-24 are scanned several times with the electron beam 202. |
