DRAM Lower Electrode Height Maximization via Support Pattern Protection
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Solution Overview
Problem
Current DRAM devices face challenges in achieving high performance and operation speed while maintaining a small size, particularly in forming capacitors with high capacitance on limited silicon substrates, where the lower electrode of the capacitor needs to be maximized without damaging the support pattern during manufacturing.
Innovation Solution
A method involving the sequential formation of mold and support layers on a substrate, followed by etching to create a contact hole, filling it with a lower electrode layer, and removing the mask pattern without damaging the support pattern, allowing the lower electrode to protrude and maximize capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the lower electrode is formed as high as possible to increase capacitance, then the capacitance of the capacitor is improved, but the support pattern may be damaged during the manufacturing process
Solution Approach 1:
The support layer is formed before the mold layer and etching process, serving as a pre-prepared protective structure that prevents damage to the support pattern during subsequent manufacturing steps. This preliminary action ensures the support pattern remains intact while allowing the lower electrode to be formed to maximum height for increased capacitance.
Solution Approach 2:
The support layer acts as an intermediary protective layer between the mold layer and the support pattern. During the etching process that forms contact holes, the support layer protects the underlying support pattern from damage while allowing the lower electrode to extend to maximum height, thus resolving the contradiction between maximizing capacitance and maintaining support pattern integrity.
2Quantity of substance
If the lower electrode height is maximized on limited substrate area, then the capacitance is increased, but the manufacturing process becomes more complex
Solution Approach 1:
The manufacturing process is segmented into distinct sequential steps: forming the support layer, forming the mold layer, performing selective etching to create contact holes, and forming the lower electrode. This segmentation allows each step to be optimized independently, enabling maximum lower electrode height while maintaining manageable process complexity through clear separation of functions.
Solution Approach 2:
Instead of increasing substrate area to accommodate larger capacitors, the solution extends the lower electrode in the vertical dimension (height) by utilizing the support layer as a protective foundation. This dimensional transition from horizontal expansion to vertical growth allows capacitance increase without expanding the limited substrate footprint, though it does add vertical process steps.
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 the formation of lower electrodes that are as high as possible, thereby increasing capacitance without damaging the support pattern, which would otherwise limit the electrode's height and capacitance.
Implementation Method 1
partially removing the support layer and the mold layer by an etching process using the mask pattern as an etching mask
Implementation Method 2
forming a lower electrode layer on the mask pattern to fill up the contact hole, such that the lower electrode layer is in contact with the interconnector in the contact hole
Data Source
AI summary
Disclosed are semiconductor devices and methods of manufacturing the same. A support layer and a mold layer are partially etched off from the substrate, to form a mold pattern and a support pattern on the substrate such that a contact hole is formed through the support pattern and the mold pattern and an interconnector is exposed therethrough. A lower electrode layer is formed on the mask pattern to fill the contact hole, and a lower electrode is formed in the contact hole by partially removing the lower electrode layer and the mask pattern. The lower electrode is contact with the interconnector and is supported by the support pattern having the same thickness as the support layer.