Semiconductor Device Sidewall Profile Control via Doped Mask
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Solution Overview
Problem
The increasing aspect ratios of gaps and trenches in semiconductor manufacturing pose challenges in filling deep narrow structures without voids or seams, as the vertical height of these features does not decrease as quickly as the horizontal width, making it difficult to deposit material uniformly.
Innovation Solution
A method involving a doped semiconductive layer is used as a mask layer, where the distribution and concentration of dopants control the sidewall profile, allowing for adjustable gap fillability and alleviating bridge issues in via holes by forming a patterned semiconductive layer with specific profiles that enhance the filling of trenches and gaps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If device structures are packed more densely to increase device concentration, then productivity is improved, but the aspect ratio of gaps and trenches increases making material filling more difficult
Solution Approach 1:
The patent changes the physical-chemical parameters of the gap fill material by using a liquid precursor composition that transforms from liquid to solid phase through deposition and thermal processing. This phase change enables the material to flow and conform to the gap geometry during liquid state, then stabilize in solid state, effectively filling high aspect ratio structures without voids
Solution Approach 2:
The invention utilizes phase transition of the gap fill material from liquid precursor to solid film through controlled deposition and thermal processing. The liquid phase allows the material to penetrate and conform to deep narrow gaps, while the solid phase provides structural integrity, solving the filling difficulty of high aspect ratio structures
2Manufacturing precision
If the vertical height of gaps and trenches is reduced to improve fillability, then manufacturing precision is improved, but device concentration cannot be increased
Solution Approach 1:
The patent changes the rheological parameters of the fill material by using a liquid precursor composition with controlled viscosity and reactivity. This allows the material to maintain flowability for penetrating deep gaps while controlling deposition rate to prevent void formation, enabling filling of high aspect ratio structures without reducing their dimensions
Solution Approach 2:
The invention replaces mechanical filling methods (such as physical vapor deposition or spin coating) with a chemical deposition process using liquid precursors. The chemical reactions enable the material to self-assemble and conformally coat the gap walls, providing uniform filling of high aspect ratio structures that mechanical methods cannot achieve
3Productivity
If deep narrow gaps are filled with material to increase device concentration, then productivity is improved, but voids or seams form in the filled material
Solution Approach 1:
The patent ensures continuous deposition action by maintaining controlled delivery of liquid precursor throughout the gap structure. The continuous flow and reaction process prevents interruption that would cause seams, while the controlled evaporation and condensation cycles ensure complete filling without void formation
Solution Approach 2:
The liquid precursor composition exhibits self-leveling and self-conforming properties due to its fluid nature and controlled reactivity. The material automatically flows to fill all available space, conforms to the gap geometry, and self-stabilizes during drying, eliminating the need for complex external control mechanisms to prevent voids
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 improves the aspect ratio and critical dimension of gap profiles, enabling better gap fillability and reducing the likelihood of voids or seams in semiconductor structures, thus enhancing the manufacturing process efficiency.
Implementation Method 1
A method involving a doped semiconductive layer is used as a mask layer, where the distribution and concentration of dopants control the sidewall profile
Data Source
AI summary
A semiconductor device includes a semiconductor substrate, a pair of source/drain regions on the semiconductor substrate, and a gate structure on the semiconductor substrate and between the pair of source/drain regions. The gate structure includes a first metal layer and a second metal layer in contact with the first metal layer. A sidewall of the first metal layer and a top surface of the semiconductor substrate form a first included angle, a sidewall of the second metal layer and the top surface of the semiconductor substrate form a second included angle. The second included angle is different from the first included angle.