Sandisk Technologies Inc.

Kotaro Jinnouchi

Yuji Takahashi

Takuya Futase

Kiyokazu Shishido

Noritaka Fukuo

Hiroto Ohori

Fumiaki Toyama

Ryo Nakamura

Toshiyuki Sega

Erika Kanezaki

Satoshi Kamata

A dielectric layer extending over a substrate has alternating first and second trenches extending in a first direction. The first trenches have a first shape in cross section along a plane that is perpendicular to the first direction and the second trenches have a second shape in cross section along the plane. Bit lines are located in at least the first trenches.

Alternating sidewall assisted patterning

Dummy bit lines of are formed in a sacrificial layer at locations where bit lines are to be formed, with bit lines separated by trenches that extend through the sacrificial layer. Enclosed air gap structures are formed in the trenches between the dummy bit lines. Subsequently, the dummy bit lines are replaced with metal to form bit lines.

Early bit line air gap formation

Wide and narrow mandrels that are used to form sidewall spacers for patterning are formed in a sacrificial layer with openings in wide mandrels near sides of the wide mandrels. Sidewall spacers are formed on the sides of mandrels and the sacrificial layer is removed. The sidewall spacers are then used for patterning of underlying layers.

Conductive line structure with openings

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Yokkaichi, Japan

Kotaro Jinnouchi