ION BEAM PROCESS METHOD

• Main Authors: HARAICHI SATOSHI, SHIMASE AKIRA, AZUMA JUNZO, TAKAHASHI TAKAHIKO, ITO FUMIKAZU
• Format: Patent
• Language: English
• Published: 22.04.1992
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PURPOSE:To form a mark with high detecting accuracy without adding photo process, by carrying out a process of high process selectivity, which generates locally a great difference in process speed, in the case of mark material in comparison with the case of films laminated on its upper layer. CONSTITUTION:In order to actualize an aluminum mark 1 under SiO2, a reactive gas 5, which accelerates processing of SiO2 but does not accelerate processing of aluminum, is used. When XeF2 is used for this gas, for example, and a mark 1 area is processed with convergent Ga ion beam 4, SiO2 is accelerated in etching, but aluminum is not accelerated. Therefore, SiO2 is processed and after aluminum is exposed, processing almost stops. So, when processing is advanced further, aluminum mark is completely exposed. As process selectivity of SiO2 and that of aluminum are in approx. 50:1 ratio at this time, dullness of aluminum mark edge is small, and the shape of a mark 1 does not differ from the shape when the mark 1 is formed by a photo process. Therefore, detecting signal changes sharply by a mark detection at the mark edge part, resulting in high accurate mark detection.