Ion Beam Activated Directional Deposition for Semiconductor Trenches
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Solution Overview
Problem
Current thin film deposition methods, such as CVD and ALD, lack control over where deposition occurs, leading to voids and non-uniformity in high aspect ratio features in semiconductor manufacturing, particularly in the formation of conformal dielectric films for sub-micron integrated circuits.
Innovation Solution
The method involves directional ion beam activation in conjunction with atomic layer deposition (ALD) cycles, where a precursor is chemisorbed and reacted with a capping compound, followed by selective ion implantation to activate specific portions of the capping layer, allowing precise control over deposition within trenches of semiconductor devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional CVD or ALD techniques are used for depositing dielectric films in high aspect ratio features, then conformal coverage is achieved, but void-free gap-fill cannot be provided
Solution Approach 1:
The ion beam activation is performed as a preliminary action before the precursor deposition step. By activating the surface with ions in advance, the subsequent precursor deposition becomes selective to activated regions, enabling directional conformal coverage that prevents void formation in high aspect ratio features
Solution Approach 2:
The ion beam activation creates local quality differences on the substrate surface by selectively activating specific regions. This spatial variation in surface activation state enables the precursor to deposit conformally only in activated areas, achieving both conformal coverage and void-free gap-fill in high aspect ratio structures
2Manufacturing precision
If ALD is used with self-limiting adsorption for thin conformal dielectric films, then uniform thickness is achieved, but areal selectivity is lost
Solution Approach 1:
Ion beam activation is performed as a preliminary step to create spatially selective reactive sites on the substrate surface. This preliminary activation pattern determines where subsequent ALD cycles will deposit material, providing areal selectivity while maintaining the self-limiting nature of ALD for uniform thickness control
Solution Approach 2:
The ion beam creates local quality variations by selectively activating specific areas of the substrate. This spatial differentiation in surface reactivity allows the ALD process to deposit material uniformly in thickness while being selective in areal distribution, combining both advantages
3Productivity
If PECVD is used for dielectric deposition, then deposition occurs, but bread-loaf shape results due to ion-induced deposition
Solution Approach 1:
The ion beam activation is performed as a preliminary step that creates controlled reactive sites before precursor introduction. This preliminary action directs the deposition to occur only in activated regions, preventing the uncontrolled ion-induced deposition that causes bread-loaf shaping in PECVD while maintaining efficient deposition rates
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 enables precise areal surface reaction and selective growth of trench-fill materials with improved atomic level thickness control, minimizing voids and ensuring uniformity in high aspect ratio features.
Implementation Method 1
performing an ion implant to the semiconductor device to activate a portion of the capping layer
Implementation Method 2
chemisorbing a precursor along a set of surfaces of the trench
Implementation Method 3
reacting the precursor with a capping compound to form a capping layer along the set of surfaces of the trench
Data Source
AI summary
Approaches herein provide precise areal surface reaction with directional ion beam activation. Exemplary approaches include selectively forming a material within a trench of a semiconductor device using a plurality of successive deposition and activation cycles. Each of the plurality of deposition and activation cycles includes forming a precursor conformally along a set of surfaces of the trench, reacting the precursor with a capping compound to form a capping layer along the set of surfaces of the trench, and performing an ion implant to the semiconductor device to activate just a portion of the capping layer. In one approach, the ion implant activates just a portion of the capping layer along a bottom surface of the trench. In another approach, the ion implant activates just a portion of the capping layer along an upper section of a sidewall of the trench.