Gap-Fill Plasma Profile Control for Buried Void Positioning
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Solution Overview
Problem
The increasing aspect ratio of pattern structures in semiconductor devices poses challenges in filling gaps without seams or voids, leading to performance deterioration due to void exposure and metal penetration during subsequent processes.
Innovation Solution
A substrate processing method involving alternating cycles of layer formation and profile change using different plasma conditions to control the position of voids within gaps, ensuring they are formed at lower areas, thereby preventing exposure during planarization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If atomic layer deposition method is used to deposit thin films sequentially, then uniform thickness film can be deposited on walls and bottom surfaces, but voids are generated at boundary surfaces where films come into contact
Solution Approach 1:
The patent changes plasma parameters (power level and frequency) between two different plasma conditions to control film deposition and profile modification. By switching from first plasma (higher frequency) for uniform deposition to second plasma (lower frequency, higher power) for profile change, the method achieves both uniform film thickness and controlled void positioning at lower areas
Solution Approach 2:
The patent employs periodic alternation between two plasma treatment cycles: first plasma application for film deposition, followed by second plasma application for profile modification. This periodic action allows repeated cycles of depositing material uniformly while then modifying the profile to push voids downward, achieving both uniformity and reliability
2Ease of manufacture
If gap structure with high aspect ratio is filled by layer-by-layer deposition, then the gap can be filled, but voids remain at boundary surfaces and may be exposed in subsequent processes
Solution Approach 1:
The patent performs preliminary profile modification using second plasma before the gap is completely filled. By changing the profile of deposited layers during the filling process, voids are pushed to lower areas in advance, preventing their exposure in subsequent planarization and metallization processes
Solution Approach 2:
The patent utilizes parameter changes in plasma treatment to control the filling process. By switching between first plasma (for deposition) and second plasma (for profile modification with different power and frequency), the method controls void positioning to prevent exposure while maintaining ease of manufacture
3Manufacturing precision
If plasma power level and frequency are adjusted, then the profile of deposited layer can be changed to control void position, but process complexity increases
Solution Approach 1:
The patent simplifies complex plasma control by using periodic alternation between two predefined plasma conditions. Instead of continuously adjusting multiple parameters, the system switches between first plasma (higher frequency) and second plasma (lower frequency, higher power) in repeating cycles, making the complex process manageable and repeatable
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 method effectively prevents voids from being exposed during subsequent processes by strategically positioning them at lower levels, maintaining film integrity and preventing metal penetration.
Implementation Method 1
forming a first layer of a first thickness on the pattern structure, wherein a first recess of a first width is formed between the first protrusion and the second protrusion by the formation of the first layer; the forming of the first layer may include applying first plasma
Implementation Method 2
changing a profile of the first layer, wherein the profile of the first layer is changed such that a width of the first recess in a first upper area adjacent to edge portions of the first protrusion and the second protrusion increases, and a width of the first recess in a first lower area below the first upper area decreases; the changing of the profile of the first layer may include applying second plasma
Data Source
AI summary
A substrate processing method for gap-filling a recess between a first protrusion and a second protrusion of a pattern structure includes: changing a profile of a layer formed on the pattern structure, wherein the changing of the profile of the layer includes: in an upper area, increasing a width of the recess to suppress formation of a void in the upper area; and, in a lower area, reducing the width of the recess to contact the layer, thereby inducing formation of a void under the lower area, and thus allows a position of the void to be adjusted.