Lam Research Corporation

Qualcomm Mems Technologies, Inc.

Chok Ho

Chung-Ju Lee

Kuo-Lung Tang

Teruo Sasagawa

Philip Don Floyd

Rao Annapragada

Ian J Morey

Xiaoming Yan

Chuan-Kai Lo

Fang-Ju Lin

The efficiency of an etching process may be increased in various ways, and the cost of an etching process may be decreased. Unused etchant may be isolated and recirculated during the etching process. Etching byproducts may be collected and removed from the etching system during the etching process. Components of the etchant may be isolated and used to general additional etchant. Either or both of the etchant or the layers being etched may also be optimized for a particular etching process.

Etching processes used in MEMS production

Method for etching organic low-k dielectric using ammonia, NH3, as an active etchant. Processes using ammonia results in at least double the etch rate of organic low-k dielectric materials than processes using N2/H2 chemistries, at similar process conditions. The difference is due to the much lower ionization potential of NH3 versus N2 in the process chemistry, which results in significantly higher plasma densities and etchant concentrations at similar process conditions.

Use of ammonia for etching organic low-k dielectrics

Process for stripping photoresist from a semiconductor wafer formed with at least one layer of OSG dielectric. The stripping process may be formed in situ or ex situ with respect to other integrated circuit fabrication processes. The process includes a reaction may be oxidative or reductive in nature. The oxidative reaction utilizes an oxygen plasma. The reductive reaction utilizes an ammonia plasma. The process of the present invention results in faster ash rates with less damage to the OSG dielectric than previously known stripping methods.

Post-etch photoresist strip with O2 and NH3 for organosilicate glass low-K dielectric etch applications

A method for etching features in an integrated circuit wafer, the wafer incorporating at least one dielectric layer is provided. Generally, the wafer is disposed within a reaction chamber. An etchant gas comprising a hydrocarbon additive and an active etchant is flowed into the reaction chamber. A plasma is formed from the etchant gas within the reaction chamber. The feature is etched in at least a portion of the dielectric layer.

Use of hydrocarbon addition for the elimination of micromasking during etching of organic low-k dielectrics

An etch that provides a high oxide to photoresist selectivity in a low-pressure, high-density plasma is provided. An extremely high reverse RIE lag is achieved, wherein the etching of small high-aspect ratio openings is possible, but that of large openings is not. A high-density plasma is generated so that carbon monoxide (CO) is ionized to CO so that at least 1 sccm equivalent of CO is provided. Excited CO neutrals (CO*) are also present within the plasma. Fluorocarbon and hydrofluorocarbon gases are also provided. The excited CO neutrals scavenge free fluorine, near the wafer surface and in the large openings, increasing polymer deposition on the photoresist and in the large openings thus reduce or stop etching in those regions. Concurrently, CO is not hindered by diffusion limitation and is readily accelerated deep into the small openings by an applied electric potential; hence, providing oxygen atoms near the bottom of the small openings which help to remove polymer at the etch front and eliminates the propensity for etch stop.

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Milpitas, CA, United States of America

Chok Ho