Surface Modification for Selective Deposition in Semiconductor Fabrication
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Solution Overview
Problem
Conventional methods for semiconductor processing, such as CMP, face challenges like dishing, erosion, high costs, and limited applicability for low-k materials, and existing plating techniques struggle with selective deposition on workpieces, leading to defects and inefficiencies in forming interconnects for integrated circuits.
Innovation Solution
A method involving a surface modification agent is applied to selectively modify the top surface of a workpiece, preventing material deposition on field areas while allowing deposition into recesses, using a system that includes a solid-state chemistry carrier and deposition apparatus to control the deposition process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional CMP processing is used for planarization, then material removal is achieved, but dishing, erosion, high costs, and limited applicability for low-k materials occur
Solution Approach 1:
The patent applies preliminary action by chemically modifying the workpiece surface before material deposition to create selective adhesion properties. This pre-treatment enables subsequent selective deposition without requiring post-deposition CMP planarization, thereby avoiding dishing, erosion, and damage to low-k materials while achieving the desired planarization effect
Solution Approach 2:
The patent replaces the mechanical CMP process with a chemical surface modification approach. Instead of using mechanical abrasion to remove material and achieve planarization, the invention uses chemical agents to selectively modify surface properties, enabling selective deposition that inherently produces planar surfaces without mechanical contact, thus eliminating dishing and erosion
2Quantity of substance
If conventional plating techniques are used for material deposition, then conductive material is deposited into recesses, but selective deposition is difficult to achieve, leading to defects and inefficiencies
Solution Approach 1:
The patent applies local quality by creating non-uniform surface properties through selective chemical modification. The surface modification agent is applied in a controlled manner to create regions with different adhesion characteristics - recess areas are modified to promote material deposition while field areas are modified to inhibit deposition, enabling precise spatial control over where conductive material is deposited
Solution Approach 2:
The patent changes the chemical parameters of the workpiece surface through surface modification. By altering surface chemistry (not just physical topology), the invention creates regions with different surface energies and adhesion properties, which directly control the deposition behavior of conductive materials. This chemical parameter change enables selective deposition without relying solely on geometric features
3Productivity
If conventional deposition methods are used, then material is deposited on both recesses and field areas, but additional processing steps like etching and CMP are required to remove excess material
Solution Approach 1:
The patent extracts the selectivity function from the deposition process itself by pre-modifying the surface. Instead of relying on complex deposition control mechanisms to prevent material deposition on field areas, the invention extracts this function to a preliminary surface treatment step, allowing subsequent deposition to automatically achieve selective filling without requiring additional etching or CMP steps to remove excess material
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 eliminates the need for planarization steps like CMP, reduces defects, and enables the use of fragile low-k materials, allowing for precise and efficient selective deposition of conductive materials in semiconductor fabrication, improving interconnect formation.
Implementation Method 1
The top surface is selectively contacted, relative to surfaces of the recess, with a surface modification agent to chemically modify the top surface
Implementation Method 2
material is selectively deposited into the recesses. Deposition of the material is inhibited on the top surface
Data Source
AI summary
In some embodiments, a workpiece-surface-influencing device preferentially contacts the top surface of the workpiece, to chemically modify the surface at desired field areas of the workpiece without affecting the surfaces of cavities or recesses in the field areas. The device includes a substance which is chemically reactive with material forming the workpiece surface. The substance can be in the form of a thin film or coating which contacts the surface of the workpiece to chemically modify that surface. The workpiece-surface-influencing device can be in the form of a solid state applicator such as a roller or a semi-permeable membrane. In some other embodiments, the cavities are filled with material that prevents surface modification of the cavity surfaces while allowing modification of the field areas, or which encourages surface modification of the cavity surfaces while preventing modification of the field areas. The modified surface facilitates selective deposition of materials on the workpiece.