| 摘要 |
PURPOSE:To determine the terminal point of ion milling operation accurately by a method wherein both ends of reference wafer arranged on a metallic sheet are pressed with electrodes to be coated with wax etc. while the time when a metallic film is deprived of the electric conduction thereof by exposing an insulating film of reference wafer to be ion milled is monitored as the terminal point of ion milling operation. CONSTITUTION:A reference wafer 2 with the same component as that of a wafer to be processed is bonded on a fixed metallic sheet 11 with wax 3. 2a and 2b represent a semiconductor substrate and an insulating film respectively while a metallic film 2c to be milled and electrodes 4 for conduction are connected to each other at both ends of the reference wafer 2. Electric wirings 5 are led from the electrodes 4 to the backside of metallic sheet 1 to be connected to a power supply and conduction detector 6. Besides, the electrodes 4 and the electric wirings 5 are insulated from the metallic sheet 1 while the electrodes 4 are coated with wax 3. When the exposed metallic film 2c is milled away, the insulating film 2b is exposed to deprive the metallic film 2c of the electric conduction thereof. At this time, the ion milling operation is to be terminated. |
