| 摘要 |
A silicon wafer is immersed in an etchant and the crystal defect portion are selectively etched, the volumetric ratio of hydrofluoric acid, nitric acid, acetic acid, and water in the etchant being (400):(5-10):(10-50):(80-120), and the iodine or iodide content of the etchant being at least 0.03 g per liter of the total volume thereof. An ellipsoidal pattern (LEP) having a diameter of approximately 10 µm thereby appears on the surface of the silicon wafer, and a large portion of the total LEP can be observed as a flow pattern. The rest of the LEP appears as a single pattern in an ellipsoidal shape as in the past. Provided are a method for evaluating a silicon wafer and an etchant for same, said method having performance equivalent to or greater than a secco solution in LEP observation and being capable of observing the LEP easily, without using a fluid containing potassium dichromate, which is a toxic substance. |
