At&t Bell Laboratories

Agere Systems Inc.

Agere Systems Guardian Corp.

Chorng-Ping Chang

Chien-Shing Pai

Wei Zhu

Daniel L Flamm

Kin Ping Cheung

Dale E Ibbotson

John A Mucha

The invention is a process for device fabrication that utilizes shallow trench isolation. The process involves the steps of forming an oxidation barrier region, e.g., silicon nitride, above a silicon substrate, providing an opening in the oxidation barrier region and in any underlying regions deposited on the silicon, providing a trench in the silicon substrate at the opening, depositing a dielectric material such as silicon dioxide in the trench, typically planarizing the trench silicon dioxide, and subsequently performing an oxidation step. The oxidation step rounds the otherwise sharp corners of the silicon at the area where the trench silicon dioxide meets the pad oxide. The invention thereby reduces or eliminates sharp corners that contribute to leakage current.

Process for device fabrication

It has been discovered that for semiconductor devices such as MOSFETs, there is significant capacitive coupling in the front-end structure, i.e., the structure from and including the device substrate up to the first metal interconnect level. The invention therefore provides a device comprising a silicon substrate, an isolation structure in the substrate (e.g., shallow trench isolation), an active device structure (e.g., a transistor structure), a dielectric layer over the active device structure, and a metal interconnect layer over the dielectric layer (metal-1 level). At least one of the dielectric components of the front-end structure comprise a material exhibiting a dielectric constant less than 3.5. This relatively low dielectric constant material reduces capacitive coupling in the front-end structure, thereby providing improved properties in the device.

Device comprising thermally stable, low dielectric constant material

Silicon nitride regions suitable for applications such as capping layers in integrated circuit fabrication are produced by an advantageous plasma deposition process. This process utilizes a combination of gases, including a silicon-containing gas, a nitrogen-containing gas, a fluorine-containing gas, and a hydrogen-containing gas. Silicon nitride having a low density of defect states and thus having excellent dielectric properties is produced.

Devices and process for producing devices containing silicon nitride

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Berkeley Heights, NJ, United States of America

Chorng-Ping Chang