Interconnect Barrier Deposition With Boron Surface Blocking
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Solution Overview
Problem
Current self-assembled monolayers fail to inhibit the growth of tantalum nitride barrier layers on tungsten surfaces while inhibiting their growth on aluminum oxide surfaces, leading to reduced electrical performance in microelectronic devices.
Innovation Solution
A method involving the use of boron-containing compounds to form a blocking layer selectively on metal surfaces, preventing the deposition of barrier layers on dielectric and aluminum oxide or aluminum nitride surfaces, thereby allowing selective deposition of barrier layers on dielectric surfaces over metal surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If selective deposition is used to remove lithographic steps for device miniaturization, then device scaling is improved, but selective inhibition of barrier layer growth on specific surfaces becomes challenging
Solution Approach 1:
The self-assembled monolayer acts as an intermediary layer between the deposition precursor and the substrate surfaces. This intermediary provides selective chemical interaction - it blocks the deposition pathway on metal surfaces through strong chemisorption while allowing deposition to proceed on dielectric surfaces. The SAM mediates the deposition process by creating different chemical environments at different locations, enabling selective barrier layer formation without requiring complex lithographic patterning.
Solution Approach 2:
The self-assembled monolayer is formed on the substrate surfaces before the barrier layer deposition process. This preliminary action prepares the surfaces with different chemical properties that will guide subsequent selective deposition. By pre-modifying the surface chemistry with the SAM, the system establishes a template that directs where the barrier layer will form, eliminating the need for lithographic steps to define deposition regions and enabling direct selective deposition based on surface chemistry alone.
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 reduces via resistance by at least 20% and improves the overall electrical performance of microelectronic devices by enabling selective deposition of barrier layers, maintaining low resistance benefits and facilitating easier desorption of molecules.
Implementation Method 1
exposing a feature extending into a semiconductor substrate to a boron-containing compound having a general formula of R(3-n)BXn or H3B—BH3... to form a blocking layer. The blocking layer forms selectively on the metal surface over the dielectric surface and one of the aluminum oxide surface or the aluminum nitride surface
Implementation Method 2
selectively depositing a barrier layer on the dielectric surface and one of the aluminum oxide surface or the aluminum nitride surface over the blocking layer
Data Source
AI summary
Methods of forming semiconductor devices by enhancing selective deposition are described. In some embodiments, a blocking layer is deposited on a metal surface before deposition of a barrier layer. The methods include exposing a substrate with a metal surface, a dielectric surface and an aluminum oxide surface or an aluminum nitride surface to a blocking molecule, such as a boron-containing compound, to form the blocking layer selectively on the metal surface over the dielectric surface and one of the aluminum oxide surface or the aluminum nitride surface.