Claims
- 1. A Flash EEPROM memory device including a doped substrate composed of silicon semiconductor material having a gate electrode stack formed on the top surface of the substrate, a source region and a drain region formed in the surface of the doped substrate comprising:the gate electrode stack comprising a floating gate electrode, and a control gate formed over the top surface of the substrate, the source region and the drain region being located in the surface of the substrate, with the source region and the drain region being located aside from the gate electrode stack in overlapping relationship with the gate electrode stack, and a surface halo region formed only in the surface of the source region extending partially into the source region and surrounded by the source region and the halo region being juxtaposed with the gate electrode stack with a slight overlap in position of the halo region with the gate electrode stack, and the drain region being formed without a halo region, whereby the channel erase function can be performed with a similar bias condition to the source erase function.
- 2. The device of claim 1 wherein a contact region is formed in the doped substrate adjacent to the drain region.
- 3. The device of claim 1 wherein the P+ BF2 dopant was ion implanted into the halo region with a dose from about 5 E 14 ions/cm2 to about 5 E 15 ions/cm2 at an energy from about 10 keV to about 30 keV.
- 4. The device of claim 3 wherein a contact region is formed in the doped substrate.
- 5. A device in accordance with claim 4 wherein the tunnel oxide layer has a thickness from about 70 Å to about 120 Å, andthe contact region is doped with boron P type dopant with a dose from about 5 E 14 ions/cm2 to about 5 E 15 ions/cm2.
- 6. The device of claim 1 wherein the device is erased with a negative Voltage on the control gate electrode and a positive voltage on the source region.
- 7. The device of claim 1 wherein the device is erased with a negative voltage from about −10 Volts to about −15 Volts on the control gate electrode and a positive voltage from about 10 Volts to about 5 Volts on the source region.
- 8. The device of claim 1 wherein the device is erased with voltages applied during the erase mode as follows:VCG = −10 V to −15 VVS = 10 V to 5 VVD = FLVSub = FLVCG = Control Gate VoltageVS = Source VoltageVD = Drain VoltageVSub = P-Well Voltage.
- 9. The device of claim 1 wherein the device is erased with voltages applied during the erase mode as follows:VCG = −10 VVS = 5 VVD = FLVSub = FLVCG = Control Gate VoltageVS = Source VoltageVD = Drain VoltageVSub = P-Well Voltage.
- 10. A Flash EEPROM memory device including:a semiconductor substrate comprising doped silicon with the substrate having a surface, a gate electrode stack comprising a tunnel oxide layer, a floating gate electrode, a dielectric layer, and a control gate formed over the surface of the semiconductor substrate, a source region and a drain region formed in the substrate self-aligned with the gate electrode stack with the source region and the drain region overlapping the gate electrode stack, and an asymmetric arrangement with a surface halo region formed only in the surface of the source region surrounded by the source region and juxtaposed with the gate electrode stack and with a slight overlap of the halo region with the gate electrode stack, whereby the channel erase function can be performed with a similar bias condition to the source erase function.
- 11. The device of claim 10 wherein a contact region is formed in the substrate adjacent to the drain region.
- 12. The device of claim 10 wherein the P+ BF2 dopant was ion implanted into the halo region with a dose from about 5 E 14 ions/cm2 to about 5 E 15 ions/cm2 at an energy from about 10 keV to about 30 keV.
- 13. The device of claim 12 wherein a contact region is formed in the doped silicon semiconductor substrate.
- 14. The device of claim 13 wherein:the tunnel oxide layer has a thickness from about 70 Å to about 120 Å, and the contact region is doped with boron P type dopant with a dose from about 5 E 14 ions/cm2 to about 5 E 15 ions/cm2.
- 15. The device of claim 10 wherein the device is erased with a negative voltage on the control gate electrode and a positive voltage on the source region.
- 16. The device of claim 10 wherein the device is erased with a negative voltage from about −10 Volts to about −15 Volts on the control gate electrode and a positive voltage from about 10 Volts to about 5 Volts on the source region.
- 17. A device in accordance with claim 10 wherein the device is erased with voltages applied during the erase mode as follows:VCG = −10 V to −15 VVS = 10 V to 5 VVD = FLVSub = FLVCG = Control Gate VoltageVS = Source VoltageVD = Drain VoltageVSub = P-Well Voltage.
- 18. A device in accordance with claim 10 wherein the device is erased with voltages applied during the erase mode as follows:VCG = −10 VVS = 5 VVD = FLVSub = FLVCG = Control Gate VoltageVS = Source VoltageVD = Drain VoltageVSub = Substrate Voltage.
- 19. A Flash EEPROM memory device including:a semiconductor substrate comprising doped silicon, field oxide regions on the surface of the substrate, a gate electrode stack comprising a tunnel oxide layer, a floating gate electrode, a dielectric layer, and a control gate formed over the formed over the surface of the semiconductor substrate, a source region and a drain region formed in the substrate self-aligned with the gate electrode stack with the source region and the drain region overlapping the gate electrode stack, and an asymmetric arrangement with a surface halo region formed only in the surface of the source region surrounded by the source region and juxtaposed with the gate electrode stack and with a slight overlap of the halo region with the gate electrode stack, whereby the channel erase function can be performed with a similar bias condition to the source erase function.
- 20. The device of claim 19 wherein a contact region is formed in the semiconductor substrate adjacent to the drain region.
- 21. The device of claim 19 wherein the P+ BF2 dopant was ion implanted into the halo region with a dose from about 5 E 14 ions/cm2 to about 5 E 15 ions/cm2 at an energy from about 10 keV to about 30 keV.
- 22. The device of claim 19 wherein a contact region is formed in the semiconductor substrate.
- 23. The device of claim 22 wherein:the tunnel oxide layer has a thickness from about 70 Å to about 120 Å, and the contact region is doped with boron P type dopant with a dose from about 5 E 14 ions/cm2 to about 5 E 15 ions/cm2.
- 24. The device of claim 23 wherein the device is erased with a negative voltage on the control gate electrode and a positive voltage on the source region.
- 25. The device of claim 19 wherein the device is erased with a negative voltage from about −10 Volts to about −15 Volts on the control gate electrode and a positive voltage from about 10 Volts to about 5 Volts on the source region.
- 26. A device in accordance with claim 19 wherein the device is erased with voltages applied during the erase mode as follows:VCG = −10 V to −15 VVS = 10 V to 5 VVD = FLVSub = FLVCG = Control Gate VoltageVS = Source VoltageVD = Drain VoltageVSub = P-Well Voltage.
- 27. The device of claim 19 wherein the device is erased with voltages applied during the erase mode as follows:VCG = −10 VVS = 5 VVD = FLVSub = FLVCG = Control Gate VoltageVS = Source VoltageVD = Drain VoltageVSub = P-Well Voltage.
Parent Case Info
This is a division of patent application Ser. No. 09/102,122, filing date Jun. 19, 1998 now U.S. Pat. No. 6,087,219, Highly Reliable Flash Memory Structure With Halo Source, assigned to the same assignee as the present invention.
US Referenced Citations (6)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0 558 404 |
Jan 1993 |
EP |