METHOD FOR MANUFACTURING FLASH MEMORY DEVICE

摘要

A method for manufacturing a flash memory device is provided to prevent fail of a word line by improving a target of a pre-cleaning process for removing a buffer oxide layer. A buffer oxide layer is formed on a semiconductor substrate defined with an active region. Threshold voltage of a memory cell is controlled by implanting dopants into the active region. The buffer oxide layer is then removed by a pre-cleaning process, wherein a target of the pre-cleaning process sets 1~1.5 times of the thickness of the buffer oxide layer. A tunnel oxide layer is then formed on the exposed active region.