Staircase Interconnect Assembly With Etch-Stop Landing Pads
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Solution Overview
Problem
It is challenging to form interconnects in the staircase region of integrated assemblies, particularly to very deep tiers, due to the high aspect ratios of the deep openings used to reach these tiers.
Innovation Solution
A method involving a stack of alternating sacrificial and insulative levels, where sacrificial material is removed, and conductive layers are formed within these levels, with etch-stop and fill materials used to facilitate the formation of conductive interconnects through anisotropic etching, allowing for improved interconnect formation to deep steps in the staircase region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If conventional methods are used to form interconnects to deep tiers, then the interconnects can reach the tiers, but the high aspect ratios of the deep openings make the process challenging and less reliable
Solution Approach 1:
The patent applies preliminary action by forming an etch-stop material layer before creating the deep openings. This etch-stop layer serves as a landing pad during the etching process, providing a controlled termination point that improves etching precision and reduces the harmful effects of high aspect ratios. The etch-stop material is deposited in advance to ensure reliable interconnect formation to deep tiers without compromising manufacturing precision.
2Quantity of substance
If deeper tiers are accessed in the staircase region, then more memory capacity is available, but the aspect ratio of openings increases making interconnect formation more difficult
Solution Approach 1:
The patent introduces an etch-stop material as an intermediary element between the fill material and the deep tiers. This intermediary layer facilitates the etching process by providing a controlled landing pad, thereby simplifying the manufacture of interconnects to deep tiers while enabling access to greater memory capacity. The etch-stop material mediates the interaction between the etching process and the deep openings, making the overall process easier to manufacture.
3Adaptability or versatility
If the staircase region is used for interconnect formation, then location flexibility is improved, but the high aspect ratios of deep openings create manufacturing challenges
Solution Approach 1:
The patent applies preliminary action by pre-forming the etch-stop material layer in the staircase region before creating the deep openings. This preliminary structure provides a reliable landing pad that maintains manufacturing precision even when utilizing the location flexibility of the staircase region for interconnect formation. The etch-stop material ensures that the high aspect ratio openings can be formed with adequate precision despite the geometric challenges of the staircase configuration.
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 method enhances the formation of conductive interconnects to deep tiers by using an etch-stop material as a landing pad for openings, improving scalability and location flexibility in staircase contact structures.
Implementation Method 1
with etch-stop and fill materials used to facilitate the formation of conductive interconnects through anisotropic etching
Data Source
AI summary
Some embodiments include an integrated assembly having a stack of alternating first and second levels. The first levels contain conductive material and the second levels contain insulative material. At least some of the first and second levels are configured as steps. Each of the steps has one of the second levels over an associated one of the first levels. A layer is over the steps and is spaced from the stack by an intervening insulative region. Insulative material is over the layer. Conductive interconnects extend through the insulative material, through the layer, through the intervening insulative region and to the conductive material within the first levels of the steps. Some embodiments include methods of forming integrated assemblies.