| 摘要 |
An EEPROM(Electrically Erasable Programmable Read Only Memory) device and a manufacturing method thereof are provided to increase a coupling ratio by forming thickly a second memory gate oxide layer on a floating junction region. An EEPROM device includes a semiconductor substrate(200), a memory gate oxide layer, a tunnel oxide layer, a floating junction region, a floating gate, an insulating pattern and a control gate. The memory gate oxide layer(215) is composed of a first memory gate oxide layer(202a) of a first thickness and a second memory gate oxide layer(210a) of a second thickness. The second thickness is larger than the first thickness. The tunnel oxide layer(214) with a third thickness is formed within the second memory gate oxide layer. The third thickness is smaller than the first thickness. The floating junction region(228) is formed under the second memory gate oxide layer in the substrate. The floating gate(216a), the insulating pattern(218a) and the control gate(220a) are sequentially formed on the memory gate oxide layer and the tunnel oxide layer.
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