Self-Calibrating DRAM Capacitor Pillar Manufacturing
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Solution Overview
Problem
The existing methods for manufacturing capacitors in DRAM elements require complex processes and high production costs due to the need for multiple photoresists and result in structures with a high aspect ratio, leading to bending issues and reduced production yield.
Innovation Solution
A method that forms a first and second oxide layer on a substrate, creates etching holes, deposits a pillar layer, forms self-calibration holes, and removes the oxide layers via anisotropic etching to reduce the number of photoresists needed and prevent excessive aspect ratios, thereby simplifying the process and preventing bending.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple photoresists are used to form the upstream structure, then the manufacturing precision is improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts and removes the second oxide layer to form self-calibration holes, eliminating the need for complex photoresist patterns. This simplifies the manufacturing process while maintaining precision by using the oxide layer removal itself to define the hole geometry.
Solution Approach 2:
The self-calibration holes are formed automatically through the selective removal of the second oxide layer, which self-organizes to create the necessary structure. This self-service mechanism eliminates the need for multiple photoresist layers and complex alignment processes.
2Productivity
If the aspect ratio of the pillar structure is increased to reduce capacitor size, then the productivity is improved, but the manufacturing precision deteriorates due to bending
Solution Approach 1:
The patent introduces self-calibration holes that extend in the vertical dimension, providing structural support that counteracts bending forces. This dimensional addition allows the pillars to maintain straightness even with high aspect ratios, enabling capacitor size reduction without sacrificing precision.
Solution Approach 2:
The self-calibration holes are formed in advance to provide structural framework before the final pillar formation. This preliminary action prevents bending during subsequent processing steps, allowing high aspect ratio structures to be manufactured with high precision.
3Use of energy by moving object
If the capacitor electrode area is enlarged to increase charge capacity, then the energy storage is improved, but the area occupied increases
Solution Approach 1:
The patent transitions from planar electrode expansion to vertical dimension utilization through self-calibration holes and high aspect ratio pillars. This allows charge capacity to be increased by extending electrodes vertically rather than horizontally, maintaining small footprint while improving energy storage.
Solution Approach 2:
The patent implements nested structures where electrodes are positioned within the self-calibration holes and along the pillar structures. This nesting allows maximum electrode surface area to be packed into minimal horizontal space, increasing charge capacity without increasing footprint.
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 reduces manufacturing complexity and costs by eliminating the need for multiple photoresists and minimizing the aspect ratio, enhancing production yield and quality by avoiding bending issues during wet etching.
Implementation Method 1
the oxide layer 3 is removed via a wet etching process to form a plurality of tubular pillars 8
Implementation Method 2
removing the first oxide layer via wet etching by injecting an etchant into the self-calibration holes to retain the pillar tubes
Data Source
AI summary
A method of manufacturing a charging capacity structure includes steps of: forming a first oxide layer, a support layer and a second oxide layer on a substrate in sequence; forming a plurality of etching holes on the surface of the second oxide layer in a matrix to run through the substrate that are spaced from each other at a selected distance; forming a plurality of pillar layers in the etching holes; removing the second oxide layer by etching; forming an etching protection layer on the surfaces of the support layer and pillar tubes that is formed at a thickness one half of the spaced distance between the etching holes such that the pillar tubes at diagonal locations form a self-calibration hole; and finally removing the first oxide layer from the self-calibration hole by etching. Through the self-calibration hole, the invention needn't to provide extra photoresists to form holes.