| 摘要 |
PURPOSE:To form elements with high accuracy on the single crystal islands of dielectric isolation type wafer by using cross alignment marks having at the end point a plurality of striped wings. CONSTITUTION:The single crystal islands 5a-5n are formed on the dielectric isolation type wafer with SiO2 film 3 which is a dielectric isolation wall. Then, one of the separated single crystal islands 5a-5n, for example, the island 5b is selected as the single crystal island for reference pattern. A cross-shaped alignment mark 6 having a plurality of striped wings 6a-6c at the end is located to the center of single crystal island 5b. Here, the mark 6 has such a size that any of the wings 6a-6c bridges over the SiO2 film 3 exposed at the surface of island 5b and the accurate alignment is carried out depending on the positional relation between wings 6a-6c and SiO2 film 3. Since such mark 6 is used, elements can be formed with high accuracy on the single crystal island of dielectric isolation type wafer. |
