Semiconductor Gate Patterning With Sidewall Spacers for Contact Reliability
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Solution Overview
Problem
The challenge of achieving effective connection between the gate and contact structure becomes urgent as the gate size shrinks in semiconductor manufacturing, particularly in dynamic random access memory (DRAM) devices, where ensuring proper contact is crucial for circuit design and transistor formation.
Innovation Solution
The method involves forming sidewall layers on the activated region, using them as a mask to pattern the initial gate, which allows for the creation of a gate structure with a protruding part connected to the body part, enhancing the contact area with the contact structure and ensuring reliable electrical connections, even with smaller feature sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the gate size is continuously shrunk to increase memory density, then the storage capacity is improved, but the connection between the gate and contact structure becomes difficult to achieve
Solution Approach 1:
The gate structure transitions from a simple planar shape to a three-dimensional structure with protruding parts that extend toward the contact structure. This dimensional change allows the gate to maintain effective electrical connection even as the overall gate footprint is reduced to increase memory density.
Solution Approach 2:
The gate is divided into multiple segments including a body part and one or more protruding parts. This segmentation allows different portions of the gate to serve different functions: the body part provides the primary gate function while the protruding parts ensure reliable connection to the contact structure, resolving the contradiction between miniaturization and connection reliability.
2Quantity of substance
If the gate feature size is reduced to improve circuit integration, then the storage capacity increases, but the manufacturing precision required becomes more difficult to achieve
Solution Approach 1:
Sidewall layers are formed on the mask structure before the actual gate patterning step. These pre-formed sidewall layers serve as spacers that define the final gate dimensions, allowing precise gate feature sizes to be achieved without requiring extremely precise direct patterning of the gate material itself.
Solution Approach 2:
The sidewall layers act as an intermediary element between the mask and the final gate structure. By using these intermediate spacer layers, the patent achieves precise gate dimensions through a self-aligned process that reduces the direct patterning precision requirements.
3Ease of manufacture
If a traditional gate patterning process is used, then the process simplicity is maintained, but only one gate can be formed per patterning step limiting circuit design flexibility
Solution Approach 1:
The patent combines multiple gate formation functions into a single patterning process. By forming sidewall layers on a mask and then patterning the gate material, the process simultaneously creates multiple gates with precise spacing and positioning, achieving both process efficiency and circuit design versatility.
Solution Approach 2:
The sidewall layer formation and gate patterning process serves multiple functions: it defines gate positions, sets gate dimensions, ensures proper spacing, and creates the protruding parts for contact connection. This multi-functional approach maintains process simplicity while enabling flexible circuit designs.
Data Source
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AI summary
The embodiments of the disclosure relate to the field of semiconductor and provide a method for manufacturing a semiconductor structure and the semiconductor structure. The method for manufacturing a semiconductor structure includes: providing an activated region; forming an initial gate located on the activated region; forming a first mask layer on a top surface of the initial gate, in which a first opening penetrating the first mask layer is provided in the first mask layer, and the first opening at least has opposite two sides extending along a first direction; forming sidewall layers located at least on sidewalls of both sides of the first opening extending in the first direction; removing the first mask layer; patterning the initial gate with the sidewall layers on both sides of the first opening as a mask to form gates. The gate can be in better contact with the contact structure when it is smaller.