Tokyo Electron Limited

Sangita Kumari

Peter Delia

Shan Hu

Henan Zhang

Eric Chih-Fang Liu

Robert Daniel Clark

Embodiments of improved process flows and methods are provided in the present disclosure to form air gaps between metal interconnects. More specifically, the present disclosure provides improved process flows and methods that utilize a wet etch process to form recesses between metal interconnects formed on a patterned substrate. Unlike conventional air gap integration methods, the improved process flows and methods described herein utilize the critical dimension (CD) dependent etching provided by wet etch processes to etch an intermetal dielectric material formed between the metal interconnects at a faster rate than the intermetal dielectric material is etched in surrounding areas of the patterned substrate. This enables the improved process flows and methods described herein to form recesses (and subsequently form air gaps) between the metal interconnects without using a dry etch process.

Wet etch process and methods to form air gaps between metal interconnects

Embodiments of a wet etch process and methods are disclosed herein to provide uniform wet etching of material within high aspect ratio features. In the present disclosure, a wet etch process is used to etch material within high aspect ratio features, such as deep trenches and holes, provided on a patterned substrate. Uniform wet etching is provided in the present disclosure by ensuring that wall surfaces of the material being etched (or wall surfaces adjacent to the material being etched) exhibit a neutral surface charge when exposed to the etch solution used to etch the material.

Methods to provide uniform wet etching of material within high aspect ratio features provided on a patterned substrate

Embodiments of a wet etch process and methods are disclosed herein to provide uniform wet etching of material formed within features (e.g., trenches, holes, slits, etc.), and on more planar areas of a patterned substrate, when a critical dimension (CD) of the features is relatively small compared to the more planar areas of the patterned substrate. In the present disclosure, uniform wet etching is provided by ensuring that wall surfaces adjacent to the material being etched exhibit a neutral surface charge when exposed to the etch solution used to etch the material.

Methods to prevent surface charge induced cd-dependent etching of material formed within features on a patterned substrate

Embodiments of improved process flows and methods are provided in the present disclosure to control fin height and channel area in a fin field effect transistor (FinFET) having gaps of variable CD. More specifically, the present disclosure provides improved transistor fabrication processes and methods that utilize a wet etch process, instead of a dry etch process, to remove the oxide material deposited within the gaps formed between the fins of a FinFET. By utilizing a wet etch process, the improved transistor fabrication processes and methods described herein provide a means to adjust or individually control the fin height of one or more the fins, thereby providing greater control over the channel area of the FinFET.

Wet etch process and method to control fin height and channel area in a fin field effect transistor (FinFET)

The present disclosure combines chemical mechanical polishing (CMP), wet etch and deposition processes to provide improved processes and methods for planarizing an uneven surface of a material layer deposited over a plurality of structures formed on a substrate. A CMP process is initially used to smooth the uneven surface and provide complete local planarization of the material layer above the plurality of structures. After achieving complete local planarization, a wet etch process is used to etch the material layer until a uniform recess is formed between the plurality of structures and the material layer is provided with a uniform thickness across the substrate. In some embodiments, an additional material layer may be deposited and a second CMP process may be used to planarize the additional material layer to provide the substrate with a globally planarized surface.

Methods for planarizing a substrate using a combined wet etch and chemical mechanical polishing (CMP) process

Embodiments of a wet etch process and method are disclosed to provide uniform etching of material formed within features (such as, e.g., trenches, holes, slits, etc.) having different critical dimension (CD). By combining a non-aqueous organic-based etch solution and an aqueous-based etch solution (either in series or in parallel) within a wet etch process, the disclosed embodiments utilize the opposing effects of CD-dependent etching to provide uniform etching of the material, regardless of CD.

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Albany, NY, United States of America

Sangita Kumari