Applied Materials, Inc.

Bi Jang

Li-Qun Xia

Anchuan Wang

Thorsten B Lill

Mihaela A Balseanu

Young Seen Lee

Meihua Shen

Shashank C Deshmukh

Jinhan Choi

Kyeong-Tae Lee

Jin Ho Jeon

Young Soo Kwon

Jae Bum Yu

A method of filling a trench is described and includes depositing a dielectric liner with a high ratio of silicon oxide to dielectric liner etch rate in fluorine-containing etch chemistries. Silicon oxide is deposited within the trench and etched to reopen or widen a gap near the top of the trench. The dielectric liner protects the underlying substrate during the etch process so the gap can be made wider. Silicon oxide is deposited within the trench again to substantially fill the trench.

Gapfill improvement with low etch rate dielectric liners

A method of plasma etching tungsten silicide over polysilicon particularly useful in fabricating flash memory having both a densely packed area and an open (iso) area requiring a long over etch due to microloading. Wafer biasing is decreased in the over etch. The principal etchant include NFand Cl. Argon is added to prevent undercutting at the dense/iso interface. Oxygen and nitrogen oxidize any exposed silicon to increase etch selectivity and straightens the etch profile. SiClmay be added for additional selectivity.

Process for etching tungsten silicide overlying polysilicon particularly in a flash memory

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Yongin, South Korea

Bi Jang