Wave Profile Capacitor Pillar Manufacturing for DRAM
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Solution Overview
Problem
The pillar-type capacitor structure in DRAM technology faces a significant reduction in plate area and capacitance due to structural weaknesses, leading to collapse issues during processing, which necessitates an increase in plate area to maintain performance.
Innovation Solution
A novel manufacturing method is introduced that forms a capacitor with a sidewall having a wave profile, increasing the plate area by forming a capacitor recess in a sacrificial layer with a wave profile, followed by the deposition of bottom and top electrode layers and a supporting layer, and subsequent removal of the sacrificial layer to create capacitor pillars, enhancing structural strength and capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a pillar-type capacitor structure is used to prevent collapse, then structural strength is improved, but plate area is significantly reduced
Solution Approach 1:
The patent applies curvature by forming the sidewall of the capacitor recess with a wave profile instead of a straight vertical profile. This curved/waved structure increases the surface area of the electrode deposited on the sidewall, thereby increasing the plate area while maintaining the pillar-type structure's structural strength to prevent collapse.
2Reliability
If supporting components are added to reinforce structural strength, then collapse resistance is improved, but plate area is lost
Solution Approach 1:
The wave profile on the sidewall serves as an integrated structural feature that both reinforces the pillar structure against collapse and simultaneously increases the electrode surface area. The curved/waved geometry provides structural rigidity while maximizing the capacitive surface area within the same footprint.
3Ease of manufacture
If a conventional vertical sidewall is used, then manufacturing is simpler, but plate area is reduced
Solution Approach 1:
The wave profile is formed during the recess etching process using standard semiconductor manufacturing techniques such as modified Bosch process or spin-on-glass methods. This approach integrates the curved profile formation into existing process flows, achieving increased plate area without significantly complicating the manufacturing process.
Data Source
AI summary
The present invention discloses a method of manufacturing a capacitor, which includes the steps of forming a capacitor recess in a sacrificial layer, wherein the sidewall of capacitor recess has a wave profile, forming a bottom electrode layer on the sidewall of capacitor recess, filling up the capacitor recess with a supporting layer, removing the sacrificial layer to forma capacitor pillar made up by the bottom electrode layer and the supporting layer, forming a capacitor dielectric layer on the capacitor pillar, and forming a top electrode layer on the capacitor dielectric layer.