METHOD FOR MANUFACTURING CONTROL GATE OF FLASH MEMORY DEVICE

摘要

PURPOSE: A method for manufacturing a control gate of a flash memory device is provided to decrease resistance of a control gate without damage to tungsten silicide, by simultaneously etched the tungsten silicide and a polysilicon layer to reducing damage to a gate in a process for etching the gate. CONSTITUTION: A tunnel oxide layer(11) and the first polysilicon layer(12) are formed on a semiconductor substrate(10), and patterned by using a mask for a floating gate. A dielectric layer(13), the second polysilicon layer(14), tungsten silicide(15) and an anti-reflecting layer(16) are formed on the entire structure including the first polysilicon layer. The anti-reflecting layer is etched for 22-28 seconds at a pressure of 350-450 milli Torr and at a plasma power of 1100-1350 Watts while using CHF3 gas of 18-22 sccm and Ar gas of 550-650 sccm. The tungsten silicide and the second polysilicon layer are etched for 20-24 seconds at a pressure of 4-6 milli Torr and at a plasma power of 380-460 Watts while Cl2 gas of 90-110 sccm and N2 gas of 4.5-5.5 sccm are used and power of 80-100 Watts is applied to the semiconductor substrate.