Semiconductor Storage Node Contact Inclined Plane Air Gap Prevention
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Solution Overview
Problem
The formation of air gaps within the storage node contact (SNC) structure during semiconductor fabrication due to the trapezoidal trench shape created by dielectric layer deposition, leading to electrical property changes and component failure.
Innovation Solution
An inclined plane is formed at the bottom of the groove containing the SNC structure, allowing polycrystalline silicon to be grown epitaxially, eliminating air gaps and enhancing the yield by ensuring uniform growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If deposition is used to form dielectric layer sidewalls, then the sidewalls can be fabricated, but the trench becomes trapezoidal (narrow at top, wide at bottom) making uniform deposition difficult and causing air gaps
Solution Approach 1:
The patent applies preliminary action by forming an inclined plane at the bottom of the trench before depositing the dielectric layer. This pre-formed geometric feature guides the deposition process to create perpendicular sidewalls rather than trapezoidal ones, preventing air gap formation during subsequent polycrystalline silicon filling.
2Ease of manufacture
If deposition is used to form dielectric layer sidewalls, then the sidewalls can be fabricated, but air gaps are formed inside the SNC causing electrical property changes and component failure
Solution Approach 1:
The inclined plane is formed in advance to control the deposition geometry, ensuring that the dielectric layer and subsequent polycrystalline silicon fill the trench uniformly without forming air gaps, thereby preventing electrical property changes and component failure.
Solution Approach 2:
The patent replaces the conventional deposition-based sidewall formation with a geometric control approach using an inclined plane, fundamentally changing the mechanism from material deposition geometry to geometric template guidance.
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
The solution prevents air gap formation, reduces component failure rates, and improves the yield by ensuring uniform and efficient growth of polycrystalline silicon within the SNC structure.
Implementation Method 1
polycrystalline silicon is grown inside the groove by taking the inclined plane as a substrate
Data Source
Figure 1~2
Figure 3(a)~3(d)
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AI summary
The embodiments provide a semiconductor structure and a fabrication method thereof. The semiconductor structure includes: a substrate, including active regions and shallow trench isolation regions arranged at intervals from each other; a plurality of isolation structures, arranged on a surface of the substrate; a plurality of grooves, arranged between the plurality of isolation structures, wherein a bottom of the groove has a first inclined plane, and the first inclined plane is formed in the active region; and a conductive plug, arranged in the groove. According to embodiments of the present disclosure, it is avoidable that air gaps are formed inside a polycrystalline silicon in the fabrication process of a storage node contact (SNC) structure.