Motorola Corporation

Joy Kimi Watanabe

Terry Grant Sparks

Nigel Graeme Cave

Matthew Thomas Herrick

John J Stankus

In accordance with embodiments of the present invention a trench-level dielectric film ( ) and a via-level dielectric film ( ) are formed overlying a semiconductor device substrate ( ). A via opening ( ) is etched in the trench-level dielectric film with a first etch chemistry that has a higher etch selectivity to the trench-level dielectric film ( ) than to the via-level dielectric film ( ). A trench opening ( ) is patterned in a photoresist layer ( ) overlying the trench-level dielectric film ( ). The via-level dielectric film ( ) is etched with a second etch chemistry to extend the via opening ( ) into the via-level dielectric film ( ). The trench-level dielectric film ( ) is etched to form a trench opening.

Method for forming a semiconductor device

In accordance with embodiments of the present invention a trench-level dielectric film (26) and a via-level dielectric film (24) are formed overlying a semiconductor device substrate (10). A via opening (42) is etched in the trench-level dielectric film with a first etch chemistry that has a higher etch selectivity to the trench-level dielectric film (26) than to the via-level dielectric film (24). A trench opening (54) is patterned in a photoresist layer (52) overlying the trench-level dielectric film (26). The via-level dielectric film (24) is etched with a second etch chemistry to extend the via opening (42) into the via-level dielectric film (24). The trench-level dielectric film (26) is etched to form a trench opening.

A buffer film (154, 164) is formed over an underlying film (153, 162) to protect that underlying film (153, 162) from damage during a removal sequence, such as polishing. Scratches, gouging, smearing that can occur to the underlying layer (153, 162) are less likely to occur because of the presence of the buffer film (154, 164). In some embodiments, an insulating film (162) is to be protected. The buffer film (164) is formed over the insulating film (162), and the insulating and buffer films (162 and 164) are patterned. During a subsequent conductive layer polishing operation in an embodiment, most of the buffer film (164) is removed. In still another embodiment, a buffer film (154) is formed over a conductive layer (153) to protect it during 'gap fill' process sequence. Although residual portions of the buffer film (154, 164) are usually removed, in some instances, those residual portions can remain if there are no significant adverse affects.

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Austin, TX, United States of America

Joy Kimi Watanabe