Semiconductor Contact Hole Formation via Cap Layer Protection
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Solution Overview
Problem
In semiconductor manufacturing, overlapping contact holes during etching processes can lead to damaged components and reduced yield rates due to repeated etching in overlapped regions.
Innovation Solution
A method involving the sequential formation of first and second contact holes in a dielectric layer, with a third contact hole overlapping the first and second holes, minimizing overlapped regions and preventing component damage by using a cap layer as an etching stop and precise photoresist layer structures for accurate pattern transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple contact holes are formed by overlapping etching processes, then the pattern transfer efficiency is improved, but the components under the contact holes are damaged due to repeated etching
Solution Approach 1:
A cap layer is formed over the components before the contact hole etching process. This cap layer serves as a protective barrier that prevents the etching chemistry from damaging the underlying components during the etching of contact holes, allowing efficient overlapping etching processes while protecting sensitive structures
Solution Approach 2:
The cap layer acts as an intermediary protective layer between the etching process and the components. It is selectively etched or removed after serving its protective function, enabling the etching process to proceed efficiently without directly contacting and damaging the components underneath
2Device complexity
If contact holes are formed in overlapping regions, then the process complexity is reduced, but the manufacturing precision deteriorates due to pattern contour distortion
Solution Approach 1:
The cap layer is prepared in advance with precise patterning that defines the contact hole locations. This preliminary structuring allows subsequent etching processes to follow well-defined contours without distortion, maintaining manufacturing precision even when multiple contact holes are formed in overlapping regions
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 reduces component damage and increases process yield by minimizing overlapped regions during contact hole formation, ensuring precise alignment and reducing defects in contact holes.
Implementation Method 1
Photolithography processes have been used as essential processes in semiconductor manufacturing procedures. They includes steps of providing a photomask or photomasks having designed patterns such as circuit patterns, doped region patterns, or contact layout patterns and transferring said patterns to a photoresist formed on a substrate by an exposure step and a development step
Implementation Method 2
After a photolithography process has been carried out, corresponding implantations or etching processes are performed to construct intricate circuit structures
Data Source
AI summary
A manufacturing method of a semiconductor device is disclosed in the present invention. First, at least one gate structure and plurality of source/drain regions on a substrate are formed, a dielectric layer is then formed on the substrate, a first contact hole and a second contact hole are formed in the dielectric layer, respectively on the gate structure and the source/drain region, and a third contact hole is formed in the dielectric layer, wherein the third contact hole overlaps the first contact hole and the second contact hole.