Trench Capacitor Integration Using Dual Hydrogen Barrier Layers
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Solution Overview
Problem
Integration of capacitor devices with ferroelectric or paraelectric materials on the same plane as logic devices is challenging due to hydrogen damage and scaling issues, requiring alternative methods for forming effective barrier layers to achieve high-density capacitor arrays.
Innovation Solution
A dual hydrogen barrier system is implemented, comprising an insulative hydrogen barrier directly adjacent to the memory device and a conductive hydrogen barrier integrated into the contact electrode, along with a high film density dielectric to protect the capacitor sidewalls and prevent hydrogen diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If capacitor devices with ferroelectric or paraelectric materials are integrated on the same plane as logic devices, then high-density capacitor arrays are achieved, but hydrogen damage occurs due to hydrogen diffusion into the capacitor materials
Solution Approach 1:
A dual barrier layer structure is introduced as an intermediary between the capacitor devices and the surrounding environment. The first barrier layer (e.g., titanium nitride, tungsten nitride, or tantalum nitride) and the second barrier layer (e.g., silicon nitride or silicon oxide) work together to block hydrogen diffusion pathways, preventing hydrogen from reaching the capacitor materials while allowing the high-density integration to proceed
Solution Approach 2:
The barrier system uses composite material structure with two distinct barrier layers having different material properties. The first barrier layer provides primary hydrogen blocking, while the second barrier layer provides additional protection and structural support. This composite approach creates a more effective hydrogen barrier than a single layer could provide, enabling reliable high-density capacitor integration
2Quantity of substance
If spacing between devices is scaled down to achieve high density, then capacitor array density increases, but formation of barrier layers becomes challenging
Solution Approach 1:
The barrier protection is segmented into two distinct layers with different functions and material compositions. This segmentation allows each layer to be optimized independently for its specific role in hydrogen blocking, making the overall barrier system more manufacturable even at scaled dimensions. The first barrier layer can be deposited using atomic layer deposition (ALD) while the second layer can be formed using different processes
Solution Approach 2:
The barrier layer formation process utilizes parameter changes in deposition techniques, particularly atomic layer deposition (ALD), to achieve conformal coverage at scaled dimensions. By controlling deposition parameters such as temperature, pressure, and precursor flow rates, high-quality barrier layers can be formed even when device spacing is reduced, maintaining manufacturing feasibility at high density
3Reliability
If barrier layers are formed to prevent hydrogen diffusion, then hydrogen damage is reduced, but device complexity increases
Solution Approach 1:
The dual barrier layer structure serves multiple functions simultaneously: the first barrier layer provides primary hydrogen blocking, the second barrier layer provides additional hydrogen protection and structural support, and together they enable high-density integration. This multi-functionality justifies the increased structural complexity by delivering multiple benefits in a single integrated solution
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
The dual hydrogen barrier effectively prevents hydrogen damage, enabling the integration of high-density capacitor arrays with improved charge storage capacity and reliability by minimizing hydrogen diffusion into the capacitor devices.
Implementation Method 1
a high film density dielectric to protect the capacitor sidewalls and prevent hydrogen diffusion
Data Source
AI summary
A device includes, in a first region, a first conductive interconnect, an electrode structure on the first conductive interconnect, where the electrode structure includes a first conductive hydrogen barrier layer and a first conductive fill material. A trench capacitor including a ferroelectric material or a paraelectric material is on the electrode structure. A second dielectric includes an amorphous, greater than 90% film density hydrogen barrier material laterally surrounds the memory device. A via electrode including a second conductive hydrogen barrier material is on at least a portion of the memory device. A second region includes a conductive interconnect structure embedded within a less than 90% film density dielectric material.