FABRICATION METHOD OF SRAM DEVICE

摘要

PURPOSE: A fabrication method of SRAM device is provided to improve VCC min(minimum operation power supply voltage) characteristics. CONSTITUTION: A fabrication method of SRAM device comprises steps of: preparing a semiconductor substrate on which first to third active areas are defined; forming a first mask pattern for masking the first active area; injecting threshold voltage control ions for NMOS into the exposed area by using the first mask pattern as an ion injection mask; removing the first mask pattern; forming a second mask pattern exposing the second/third active areas; injecting threshold voltage control ions for NMOS into the exposed second/third active areas by using the second mask pattern as an ion injection mask; removing the second mask pattern; forming a third mask pattern exposing only the second active area; injecting threshold voltage control ions for NMOS into the exposed second active area by using the third mask pattern as an ion injection mask; and removing the third mask pattern.