摘要 |
<p>A holder (102) made from an HF-resistant material includes annular suction pads (105, 108). The suction pad (105) is used to hold a small silicon substrate by suction, and the suction pad (108) is used to hold a large silicon substrate by suction. This makes silicon substrates with various sizes processable. A silicon substrate is held by suction by reducing a pressure in a space in a groove of the suction pad by a pump (120). An opening (103) is formed in the holder (102) so that the both surfaces of the silicon substrate are brought into contact with an HF solution (115). The silicon substrate is anodized by applying a DC voltage by using a platinum electrode (109a) as a negative electrode and a platinum electrode (109b) as a positive electrode, and thereby a substrate having a porous layer is produced. <IMAGE></p> |