Semiconductor Via Plug Metal Etching Stopper
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Solution Overview
Problem
During the etching process for forming openings in semiconductor devices, the plugs are often etched, leading to structural integrity issues and inefficiencies due to the lack of effective etching stoppers.
Innovation Solution
A semiconductor device design that incorporates a metal layer with different metal elements, such as Al, Hf, or Zr, as an etching stopper on the plugs to prevent etching of the via plugs during the formation of openings, while allowing the metal layer to function as an electrical connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If etching is performed to form openings in the substrate, then openings are successfully formed, but the plugs are etched and damaged
Solution Approach 1:
A metal layer comprising a first metal element different from the plug material is introduced as an intermediary between the etching environment and the plug. This metal layer acts as a protective mediator that prevents direct contact between the etching chemicals and the plug, thereby preventing plug etching while allowing opening formation to proceed
Solution Approach 2:
The metal layer is formed on the plug surface before the etching process begins. This preliminary protective coating is deposited in advance to prevent plug etching during subsequent opening formation, eliminating the need for post-etching plug repair or replacement
2Reliability
If a protective layer is added to prevent plug etching, then plug integrity is maintained, but the device structure becomes more complex
Solution Approach 1:
The metal layer is designed to serve multiple functions simultaneously: it acts as an etching stopper to protect the plug, provides electrical connection between components, and can serve as a conductive pathway. This multi-functionality reduces the need for additional separate layers, thereby limiting the increase in device complexity while maintaining plug integrity
3Productivity
If conventional etching is used to form openings, then the process is simple and fast, but the plugs are etched and require additional repair steps
Solution Approach 1:
The metal layer serves as an intermediary protective barrier that enables conventional high-speed etching processes to proceed without damaging the plugs. By introducing this single protective layer, the etching process can maintain its speed and simplicity while the metal layer absorbs the harmful etching effects, preventing plug damage and eliminating subsequent repair steps
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
The metal layer effectively prevents the etching of via plugs, ensuring the structural integrity of the semiconductor device and enabling high-speed etching of the substrate without compromising the plug's integrity.
Implementation Method 1
a metal layer with different metal elements, such as Al, Hf, or Zr, as an etching stopper on the plugs to prevent etching of the via plugs during the formation of openings
Implementation Method 2
allowing the metal layer to function as an electrical connection
Data Source
AI summary
A semiconductor device includes a first substrate, a first insulating film provided on the first substrate, and a first plug provided in the first insulating film. The device further includes a first layer provided on the first insulating film and a first metal layer provided on the first plug in the first layer and electrically connected to the first plug. The device further includes a second metal layer including a first portion provided in the first layer and a second portion provided on the first layer and electrically connected to the first metal layer.