3D Memory Conductive Layer Structure With Selective Metal Nitride Deposition
Solution Overview
Problem
Current three-dimensional memory devices face challenges in forming reliable electrically conductive layers that effectively integrate with dielectric metal oxide blocking dielectric structures, particularly in suppressing metal nitride growth on insulating layers during deposition processes.
Innovation Solution
A method involving selective metal nitride deposition is employed, where metal nitride is grown from physically exposed surfaces of dielectric-metal-oxide blocking dielectric portions while retarding growth on insulating layers, forming tubular metal nitride portions that surround dielectric-metal-oxide blocking dielectric portions and metal fill material portions that contact overlying and underlying insulating layers or metal nitride liners with reduced thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional metal deposition methods are used to form electrically conductive layers, then conductivity can be achieved, but structural integrity and material utilization are compromised
Solution Approach 1:
The patent applies local quality by forming metal nitride portions only in specific locations where needed for conductivity, rather than uniformly across all surfaces. The selective deposition process creates metal nitride layers only on certain dielectric portions, optimizing material usage while maintaining structural integrity in critical areas.
Solution Approach 2:
The patent utilizes parameter changes by controlling the deposition conditions to achieve different material phases and properties. By adjusting deposition parameters, the process forms metal nitride portions with specific thicknesses and compositions that optimize both conductivity and structural properties, preventing material wastage through precise control.
2Manufacturing precision
If metal nitride is deposited on all surfaces, then complete coverage is achieved, but unwanted growth on insulating layers increases manufacturing complexity
Solution Approach 1:
The patent employs an intermediary approach by introducing a dielectric metal oxide blocking layer that acts as a selective barrier. This blocking dielectric prevents unwanted metal nitride growth on certain insulating layers while allowing deposition on target areas, simplifying the overall process control without requiring complex selective deposition mechanisms.
Solution Approach 2:
The patent applies segmentation by dividing the deposition process into distinct stages with different selectivity characteristics. The process segments growth into controlled portions (metal nitride on target dielectric) and blocked portions (no growth on insulating layers), achieving precise control through process segmentation rather than complex real-time control.
3Reliability
If thicker metal nitride layers are formed, then conductivity improves, but material consumption and process complexity increase
Solution Approach 1:
The patent applies partial action by forming metal nitride portions with sufficient thickness to achieve the required conductivity in critical areas, rather than uniformly thickening all layers. The selective deposition ensures adequate conductivity where needed while minimizing material consumption in areas where full coverage is not required, balancing performance with material efficiency.
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 enhances the integration of electrically conductive layers with dielectric-metal-oxide blocking dielectric structures, improving the reliability and conductivity of three-dimensional memory devices by controlling metal nitride growth and ensuring proper contact with insulating layers.
Implementation Method 1
performing a selective deposition process which grows a metal nitride material from physically exposed surfaces of the set of dielectric-metal-oxide blocking dielectric portions in the backside recesses while suppressing or retarding growth of the metal nitride material from surfaces of the insulating layers
Data Source
AI summary
A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers, a memory opening vertically extending through the alternating stack, and a memory opening fill structure located in the memory opening and including a set of dielectric-metal-oxide blocking dielectric portions located at levels of the electrically conductive layers, a memory material layer, and a vertical semiconductor channel. Each of the electrically conductive layers includes a tubular metal nitride portion and a metal fill material portion, each of the tubular metal nitride portions laterally surrounds and contacts a respective one of the dielectric-metal-oxide blocking dielectric portions, and each metal fill material portion either contacts respective overlying and underlying insulating layers of the insulating layers, or contacts respective upper and lower metal nitride liner portions which have a smaller thickness than the tubular metal nitride portions.