| 摘要 |
PURPOSE:To accurately control the thickness of a film to be etched by piercing a hole having an arc-shaped cross-section in the film so that the hole reaches a layer under the film and by comparing a circle drawn by the peripheral edge of the hole with a circle drawn by the boundary between the film and the under layer during etching. CONSTITUTION:The surface of a semiconductor substrate 2 is coated with an insulating layer 1 of SiO2 or the like and a semiconductor film 3 of single crystal silicon is grown on the layer 1 in a vapor phase. A hole 4 having an arc-shaped cross-section is pierced in the film 3 with a pole lap so that the hole reaches the layer 1. The size of a circle 6 drawn by the peripheral edge 5 of the hole 4 is compared with the size of a circle 8 concentric with the circle 6 and drawn by the boundary 7 between the film 3 to be etched and the under layer 1 to judge the thickness of the film 3 during etching.
|
