Selective Deposition Using Inhibitor Layers on Mixed Film Surfaces
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Solution Overview
Problem
The challenge in semiconductor manufacturing is the need for selective deposition of specific films on surfaces with multiple materials, particularly in environments involving low-k materials, SiOx, and metal oxides, where existing methods struggle to selectively deposit layers without affecting adjacent films.
Innovation Solution
A method involving the use of an inhibitor layer, such as an alkyl or aryl aldehyde, is applied to selectively deposit a layer of interest by forming an inhibitor layer on a first film surface, exposing a second film surface, and removing the inhibitor to deposit the layer of interest only on the second film, which includes materials like low-k materials, SiOx, and metal oxides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional deposition methods are used on surfaces with multiple materials, then deposition can be performed on all surfaces, but selective deposition of specific films cannot be achieved
Solution Approach 1:
An inhibitor layer is introduced as an intermediary substance that selectively adsorbs to metal film surfaces (W, Mo, Ru, Cu, Co and their oxides) but not to dielectric surfaces (low-k, SiOx). This inhibitor layer acts as a mediator that prevents deposition on metal surfaces while allowing deposition on dielectric surfaces, achieving selective film formation without complex process modifications
Solution Approach 2:
The inhibitor layer is formed in advance before the deposition of the layer of interest. This preliminary action of adsorbing the inhibitor to metal surfaces ensures that when deposition subsequently occurs, the metal surfaces are already protected, enabling selective deposition on dielectric surfaces without requiring post-processing intervention
2Manufacturing precision
If deposition is performed on all exposed surfaces, then complete coverage is achieved, but adjacent films are inadvertently affected
Solution Approach 1:
The inhibitor layer serves as a protective intermediary that specifically binds to metal surfaces, creating a barrier that prevents the deposition of the layer of interest on metal films while leaving dielectric surfaces exposed and receptive to deposition, thus avoiding unintended film formation on adjacent structures
Solution Approach 2:
The inhibitor layer provides locally differentiated protection: it adsorbs strongly to metal surfaces (W, Mo, Ru, Cu, Co and their oxides) to prevent deposition, while showing no affinity for dielectric surfaces (low-k materials, SiOx). This local differentiation in chemical interaction enables precise spatial control over where deposition occurs
3Reliability
If existing inhibitor materials are used, then some selectivity is achieved, but reliable selective deposition in low-k and metal oxide environments cannot be achieved
Solution Approach 1:
The invention changes the chemical parameters of the inhibitor material from conventional options to specifically selected compounds (2,6-di-tert-butylpyridine, 4-tert-butylpyridine, or 2,6-di-tert-butuaniline) that exhibit optimized adsorption characteristics. These parameter changes in inhibitor chemistry enable reliable differentiation between metal and dielectric surfaces including low-k and metal oxide environments, achieving consistent selective deposition across diverse material compositions
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for precise deposition of layers like tantalum nitride without forming on metal films, reducing via resistance and improving process flexibility through in-situ and ex-situ processes.
Implementation Method 1
forming an inhibitor layer on the first surface of the first film... the inhibitor layer comprises an alkyl aldehyde... forming a layer of interest surrounding the second surface of the second film
Data Source
AI summary
Provided discloses an inhibitor capable of selectively adsorbing in a plurality of film environments and selectively depositing a subsequent film. Also provided are methods for selective deposition of a layer of interest with improved reliability by using an inhibitor having a superior selective deposition capability which can include forming of an inhibitor layer on a first surface wherein the inhibitor layer is chemically-adsorbed only to the first surface and is not adsorbed to a second surface.