Vertical Memory Staircase Contact With Integrated Dummy Channel Support
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Solution Overview
Problem
Challenges exist in designing and manufacturing vertical memory devices, particularly in the staircase region, where contacts and dummy channels are physically separated, leading to complex structure arrangements and increased stress with multiple layers, which complicates the manufacturing process and increases costs.
Innovation Solution
A combined dummy channel and contact (DCH-CT) structure is introduced, which integrates the functions of both into a single structure, providing electrical connection and support to gate layers, using conductive materials with higher Young's modulus to mitigate bending and simplify the manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If contacts and dummy channels are physically separated in the staircase region, then electrical connection can be established, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent combines the contact structure and dummy channel structure into a single integrated structure. The contact structure includes a conductive plug extending through the stack to contact the gate layer, while also serving as a dummy channel that provides mechanical support to the staircase region. This merging eliminates the need for separate contacts and dummy channels, reducing structural complexity while maintaining both electrical connection and mechanical support functions.
2Quantity of substance
If multiple layers are added to increase storage density, then data storage capacity improves, but stress in the staircase region increases
Solution Approach 1:
The contact structure uses a composite material system consisting of a conductive plug (first material) and an insulating layer (second material) with different mechanical properties. The conductive plug provides electrical connection while the insulating layer provides mechanical support and stress distribution. This composite structure enables the staircase region to support higher numbers of gate layers by distributing and managing the increased stress, thereby allowing higher storage density without excessive stress accumulation.
3Reliability
If separate contacts and dummy channels are used, then electrical connection is provided, but manufacturing steps and costs increase
Solution Approach 1:
The patent merges the contact and dummy channel fabrication into a single manufacturing process flow. The contact structure is formed by depositing the conductive plug material and patterning it to extend through the stack, simultaneously creating both the electrical contact and the dummy channel support structure. This eliminates the need for separate manufacturing steps for contacts and dummy channels, reducing process complexity and manufacturing costs while ensuring reliable electrical connection to the gate layers.
Data Source
AI summary
Aspects of the disclosure provide a semiconductor device. The semiconductor device includes a stack structure and a contact structure. The stack structure comprises interleaved gate layers and insulating layers. The contact structure comprises a conductive structure and one or more insulating structures. The conductive structure can extend through the stack structure and form a conductive connection with one of the gate layers. The one or more insulating structures surround the conductive structure and electrically isolate the conductive structure from remaining ones of the gate layers. The one or more insulating structures further include one or more first insulating structures. Each of the one or more first insulating structures is disposed between an adjacent pair of the insulating layers, and the one or more first insulating structures are disposed on a first side of the one of the gate layers.