US 6,635,532 B2Granted

Method for fabricating NOR type flash memory device

AssigneeSamsung Electronics Co., Ltd.

InventorsYun-Heub Song, Woon-Kyung Lee

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Abstract

Disclosed is a method for fabricating a NOR flash memory device where a buried common source line made of an impurity diffusion layer has an even surface or a lower step difference. The method includes forming adjacent isolation layers that define an active region there between within a semiconductor substrate. Then, a floating gate pattern is formed overlying the active region. An inter-gate dielectric film and a control gate film are sequentially formed overlying the floating gate pattern. The control gate film, the inter-gate dielectric film, and the floating gate pattern are sequentially patterned, thereby forming a plurality of word lines extending across the active region. The active region between the adjacent isolation layers and the isolation layers are removed, adjacent to one sidewall of the word lines, thereby forming a common source line region. Next, impurities are implanted into the common source line region, thereby forming a common source line made of an impurity diffusion layer.

Claims17

Dependent claims

A method for fabricating a NOR flash memory device, the method comprising:

forming adjacent isolation layers that define an active region therebetween within a semiconductor substrate;
forming a floating gate pattern overlying the active region;
sequentially forming an inter-gate dielectric film and a control gate film, overlying the floating gate pattern;
sequentially patterning the control gate film, the inter-gate dielectric film, and the floating gate pattern, thereby forming a plurality of word lines extending across the active region, the word lines each having sidewalls;
forming a photo resist pattern exposing the active region and the isolation layers along one sidewall of the word line;
etching the exposed active region, using the photo resist pattern, the word lines, and the exposed isolation layers as an etch mask;
removing the exposed isolation layers, using the photo resist pattern and the word lines as an etch mask, to form a common source line region;
and
removing the photo resist pattern;
and
implanting impurities in the common source line region, thereby forming a common source line made of an impurity diffusion layer.

8 more elements

Dependencies are inferred from the claim text.