Word Line Contact Etching With Barrier Layer Protection
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Solution Overview
Problem
The challenge of securing reliable electrical connections between elements in semiconductor devices becomes increasingly difficult as devices are miniaturized and demand higher integration, leading to potential reliability issues in electrical connections.
Innovation Solution
A method of manufacturing semiconductor devices involves using a specific etching gas mixture of difluoromethane (CH2F2) and octafluorobutyne (C4F8) with a ratio of at least 1:1.5 to form barrier layers on exposed substrate regions, ensuring precise etching processes for contact holes, and employing multiple etching steps to create reliable connections through various layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If device miniaturization and integration are increased to meet electronic device demands, then productivity and functionality are improved, but reliability of electrical connections deteriorates
Solution Approach 1:
A barrier layer is formed on the exposed logic active region surface during the etching process before subsequent processing steps. This preliminary protective action prevents contamination and damage to the logic active region, ensuring reliable electrical connections are maintained throughout further manufacturing steps.
Solution Approach 2:
The barrier layer acts as an intermediary between the etching environment and the logic active region. It provides a protective interface that allows the etching process to proceed while preventing harmful effects on the underlying logic active region, thus maintaining connection reliability during miniaturization.
2Manufacturing precision
If multiple etching processes are performed to form contact holes through various layers, then manufacturing precision is improved, but process complexity increases
Solution Approach 1:
Multiple etching processes are combined into a single integrated etching step that simultaneously forms both the logic active region contact hole and the word line contact hole. This merging approach maintains the precision needed for contacting different structures while reducing the overall number of separate etching processes required.
Solution Approach 2:
The etching process is designed to perform multiple functions simultaneously: forming contact holes through the buried insulation layer, exposing the logic active region, and creating word line contact holes. This multi-functional approach reduces process complexity while maintaining manufacturing precision for all contact structures.
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 enhances the reliability of electrical connections by protecting sensitive substrate regions during etching, allowing for precise formation of contact plugs, thereby improving the integrity of semiconductor device performance.
Implementation Method 1
The first etching gas may include difluoromethane (CH2F2) and octafluorobutyne (C4F8), where a ratio of difluoromethane to octafluorobutyne in the first etching gas may be at least 1:1.5. The first etching process may include forming a barrier layer on the exposed logic active region of the substrate, the barrier layer being formed from the first etching gas reacting with a material of the substrate in the logic active region of the substrate that is exposed by the logic active region contact hole
Data Source
AI summary
A method of manufacturing a semiconductor device may include sequentially forming a word line filling a word line trench of a substrate and a buried insulation layer on the word line, performing a first etching process of forming a logic active region contact hole extending to an inner portion of a logic active region of the substrate and a word line contact hole extending to an inner portion of the buried insulation layer, and performing a second etching process so that the word line contact hole extends to an inner portion of the word line. The first etching process may be performed using a first etching gas, which may include difluoromethane (CH2F2) and octafluorobutyne (C4F8) and where a ratio of difluoromethane to octafluorobutyne may be at least 1:1.5. The first etching gas may react with the logic active region to form a barrier layer.