Groove Capacitor Structure With Isolated Wet Etching
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Solution Overview
Problem
In semiconductor manufacturing, the miniaturization of capacitor structures makes it difficult to maintain or increase capacitance values, and the formation of double-sided capacitor structures often results in etching defects due to edge size and etching load effects, leading to issues like uneven electrode deposition and leakage holes.
Innovation Solution
A method is introduced where a first supporting layer is placed in the peripheral region to cover the top surface and side walls of the first dielectric layer, and a second supporting layer is arranged in the array region, with the groove-type lower electrode penetrating through the second supporting layer, ensuring that the etching solution only contacts one dielectric layer, thus preventing substrate exposure and maintaining structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the capacitor structure is miniaturized to increase integration density, then the area occupied by each capacitor is reduced, but the capacitance value becomes difficult to maintain or increase
Solution Approach 1:
The patent transitions from a planar capacitor structure to a three-dimensional groove-type structure. The lower electrode extends vertically into grooves etched in the dielectric layer, utilizing the third dimension (depth) to increase electrode surface area without increasing the planar footprint. This dimensional change allows capacitance to be maintained or increased while the capacitor occupies less area on the substrate.
Solution Approach 2:
The lower electrode is nested within grooves formed in the dielectric layer, with the electrode material filling the groove structure. This nesting approach allows the electrode to occupy the vertical space within the dielectric layer, effectively increasing the electrode surface area available for capacitance formation without requiring additional lateral space.
2Strength
If a double-sided capacitor structure with supporting layer is formed, then the structural support is improved, but etching defects occur due to edge size effect and etching load effect
Solution Approach 1:
The patent segments the supporting layer into two distinct layers: a first supporting layer that extends into the peripheral region and a second supporting layer that remains in the array region. This segmentation allows different etching processes to be applied to different regions, with the first supporting layer providing support during peripheral etching operations and the second supporting layer providing support during array region etching operations, thereby reducing etching defects caused by edge effects and load effects.
Solution Approach 2:
The first supporting layer is specifically positioned in the peripheral region where edge size effects and etching load effects are most pronounced. This local placement provides enhanced structural support and etching control precisely where needed, allowing for better etching quality in the critical peripheral regions without compromising the overall structural integrity of the capacitor array.
3Area of moving object
If the groove-type lower electrode penetrates through multiple layers, then the electrode surface area is increased, but the risk of over-etching and substrate exposure increases
Solution Approach 1:
The first supporting layer is formed to extend into the peripheral region and provide protective support before the groove etching process begins. This preliminary structural preparation ensures that when grooves are etched to form the lower electrode, the first supporting layer is already in place to prevent over-etching and substrate exposure, allowing the electrode surface area to be increased safely.
Solution Approach 2:
The first supporting layer acts as an intermediary protective layer between the etching process and the substrate. It provides a buffer that prevents the etching solution from directly contacting and damaging the substrate, while still allowing the groove-type lower electrode to penetrate through the dielectric layer and increase its surface area for capacitance formation.
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 prevents over-etching and peeling of the substrate, ensures even electrode deposition, and maintains the structural and functional integrity of the semiconductor structure by isolating the etching solution, thereby improving the manufacturing efficiency and reducing process complexity.
Implementation Method 1
The third dielectric layer is removed through a wet etching process
Data Source
AI summary
A method for manufacturing a semiconductor structure includes: a substrate is provided, in which the substrate includes an array region and a peripheral region adjacent to each other, and the array region includes a buffer region connected with the peripheral region; a first dielectric layer, a first supporting layer, a second dielectric layer, a second supporting layer and a third dielectric layer, which are successively stacked onto one another, are formed on the substrate; a groove-type lower electrode, which at least penetrates through the third dielectric layer and the second supporting layer, is formed in the buffer region; the third dielectric layer is removed through a wet etching process; and the second supporting layer in the peripheral region is etched after the third dielectric layer is removed.