Method for converting a floating gate non-volatile memory cell to a read-only memory cell and circuit structure thereof

A method of making a ROM cell comprising:

• forming an EEPROM cell having a floating gate, a control gate, a first well and a selection gate;
• forming a metal line overlying the EEPROM cell;
• and
• converting the EEPROM cell to ROM cell by forming a contact between the metal line and the floating gate, wherein the contact connects the floating gate to the first well.

A method of forming a memory comprising:

• forming an EEPROM cell, the EEPROM cell having a well, a floating gate overlying the well, a control gate and a selection gate;
• and
• converting the EEPROM cell into a ROM cell, wherein the converting comprises:
• electrically connecting the floating gate to the selection gate.

A method of forming a memory comprising:

• forming an EEPROM cell, the EEPROM cell having a well, a floating gate overlying the well, a control gate and a selection gate;
• and
• converting the EEPROM cell into a ROM cell, wherein the converting step comprises:
• electrically connecting the floating gate to the well.

A method of making a ROM cell, comprising:

• forming an EEPROM cell having a floating gate, a control gate, a first well and a selection gate;
• forming a metal line overlying the EEPROM cell;
• converting the EEPROM cell to ROM cell by forming a contact between the metal line and the floating gate;
• and
• forming a second well at the same time the first well is formed, wherein the control gate is in the second well.