Method of fabricating flash memory device
AssigneeHynix Semiconductor Inc.
InventorsEun Soo Kim, Jung Geun Kim, Suk Joong Kim
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Abstract
The present invention relates to a method of fabricating a flash memory device and includes forming an air-gap having a low dielectric constant between word lines and floating gates. Further, a tungsten nitride (WN) layer is formed on sidewalls of a tungsten (W) layer for a control gate. Hence, the cross section of the control gate that is finally formed can be increased while preventing abnormal oxidization of the tungsten layer in a subsequent annealing process. The method of the present invention can improve interference between neighboring word lines and, thus improve the reliability of a device. Accordingly, a robust high-speed device can be implemented.
Claims20
A method of fabricating a flash memory device, comprising:
- providing a semiconductor substrate in which a tunnel dielectric layer, a first conductive layer, a dielectric layer, and a second conductive layer are formed;
- patterning the second conductive layer and the dielectric layer;
- forming an anti-oxidization layer over the first conductive layer, including the patterned second conductive layer and the patterned dielectric layer;
- etching the anti-oxidization layer, while etching the first conductive layer, in such a manner that the anti-oxidization layer remains on sidewalls of the second conductive layer and the first conductive layer is patterned;
- forming a first insulating layer surrounding each element of the remaining anti-oxidization layer and having a top with an overhang shape;
- and
- forming a second insulating layer having an air-gap between the first insulating layer on sidewalls of adjacent elements of the patterned first conductive layer.
Dependencies are inferred from the claim text.