Abstract: Methods of forming EEPROM memory cells having uniformly thick tunnelling oxide layers include the steps of forming a preliminary field oxide isolation region of first thickness at a face of a semiconductor substrate of first conductivity type (e.g., P-type) and then forming a tunneling oxide layer on the face, adjacent the preliminary field oxide isolation region. The memory cell's drain region dopants are then implanted through the preliminary field oxide isolation region and into the substrate to form a preliminary drain region of second conductivity type. The preliminary field oxide isolation region is then grown to a second thickness greater than the first thickness by oxidizing the portion of the substrate containing the implanted dopants, to form a final field oxide isolation region which may have a thickness of about 2000 .ANG..

Abstract: A nonvolatile memory device and a manufacturing method thereof is disclosed. The device includes a gate electrode of a memory cell arranged in a memory cell region and having a floating gate electrode formed of a first conductive layer, an insulating film formed on the floating gate electrode and a control gate electrode formed of a second conductive layer on the insulating film; a gate electrode formed of a second conductive layer and arranged in a peripheral circuit region surrounding the memory cell region; a resistance device formed of the first conductive layer arranged in a boundary region between the memory cell region and the peripheral circuit region and/or the peripheral circuit region; an insulating film formed on a part of a surface of the resistance device; and a capping layer formed of the second conductive layer on the insulating film. Thus, generation of a stringer can be prevented so that malfunction of a device can be prevented.

Abstract: An EEPROM device in which a high voltage is applied to the chip during the memory cell operation and a method for the manufacturing the same are disclosed. On a P-type semiconductor substrate, a first N-well is formed in a surface portion of the substrate in the cell array region and a second N-well is formed in a first surface of the substrate in the peripheral circuit region. An EEPROM memory cell is formed on the first P-well and a first NMOS transistor is formed on the second P-well. Also, a second NMOS transistor is formed on a second surface portion of the semiconductor substrate in the peripheral circuit 10 region and a PMOS transistor is formed on the second N-well. The impurity concentrations of the first and second P-wells are controlled in accordance with the characteristic of the MOS transistors to be formed. Further, a second NMOS transistor having a resistance against a high voltage is directly formed on the P-type substrate. Thus, the electric characteristic of the EEPROM device is enhanced.

Abstract: An EEPROM device in which a high voltage is applied to the chip during the memory cell operation and a method for the manufacturing the same are disclosed. On a P-type semiconductor substrate, a first N-well is formed in a surface portion of the substrate in the cell array region and a second N-well is formed in a first surface of the substrate in the peripheral circuit region. An EEPROM memory cell is formed on the first P-well and a first NMOS transistor is formed on the second P-well. Also, a second NMOS transistor is formed on a second surface portion of the semiconductor substrate in the peripheral circuit 10 region and a PMOS transistor is formed on the second N-well. The impurity concentrations of the first and second P-wells are controlled in accordance with the characteristic of the MOS transistors to be formed. Further, a second NMOS transistor having a resistance against a high voltage is directly formed on the P-type substrate. Thus, the electric characteristic of the EEPROM device is enhanced.