Method to code flashROM using LDD and source/drain implant
A new method to form ROM devices in the manufacture of an integrated circuit device is achieved. The method comprises providing a semiconductor substrate. MOS gates are formed overlying the substrate. Ions are implanted into the substrate to form lightly doped drains for the MOS gates. A masking layer is used to offset the lightly doped drains from selective MOS gates to thereby form constant-OFF MOS gates. Spacers are next formed on the sidewalls of the MOS gates. Finally, ions are implanted into the substrate to form source and drain regions for the MOS gates to thereby complete the ROM devices in the manufacture of said integrated circuit device. The method may be extended to form ROM devices from Flash gates in a FlashROM process.
Taiwan Semiconductor Manufacturing Co. Ltd.
H H
H01L H01L
inventional additional
Jiun-Nan
Chen