Contact Structure Manufacturing via Region-Specific Exposure Overlay Shifts
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Solution Overview
Problem
The manufacturing process of integrated circuits (ICs) is prone to defects due to factors like process stability and uniformity, which affects production yield, and there is a need to improve yield by modifying process conditions and inspection approaches.
Innovation Solution
A manufacturing method for contact structures involves performing different exposure steps on various substrate regions with overlay shifts, allowing for easier detection of defects and adjustment of process conditions to enhance yield, including forming a dielectric layer, a photoresist layer, and performing exposure and develop processes with specific overlay shifts to create openings in the photoresist layer, followed by etching to form contact holes and structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If different exposure steps are performed with overlay shifts to different regions of the substrate, then defects can be detected more easily and process conditions can be optimized, but the process complexity increases
Solution Approach 1:
The patent applies local quality by performing different exposure steps with overlay shifts to specific regions of the substrate. First exposure steps are performed to first regions without overlay shifts, while second exposure steps are performed to second regions with overlay shifts by a predetermined distance. This regional differentiation allows defects to be detected more easily in the second regions, enabling optimization of process conditions to improve manufacturing yield.
2Difficulty of detecting and measuring
If overlay shifts are applied in exposure steps, then process margin becomes smaller and defects are detected more easily, but manufacturing precision requirements become more stringent
Solution Approach 1:
The patent applies partial action by performing overlay shifts only in specific second exposure steps targeting second regions of the substrate, rather than applying overlay shifts uniformly across all regions. The overlay shift is applied by a first predetermined distance only where needed for defect detection, allowing the process to benefit from enhanced defect detectability while maintaining manufacturing precision in regions where overlay shifts are not applied.
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 method allows for improved detection and reduction of defects, enabling the modification of process conditions to enhance the manufacturing yield of contact structures by adjusting the process window and improving etching uniformity.
Implementation Method 1
An exposure process is performed. The exposure process includes a plurality of first exposure steps and a plurality of second exposure steps
Data Source
AI summary
A manufacturing method of a contact structure includes the following steps. A substrate is provided, and the substrate includes a first region and a second region. A dielectric layer is formed on the substrate. A photoresist layer is formed on the dielectric layer. An exposure process is performed. The exposure process includes first exposure steps and second exposure steps. Each of the first exposure steps is performed to a part of the first region of the substrate. Each of the second exposure steps is performed to a part of the second region of the substrate. Each of the second exposure steps is performed with a first overlay shift by a first predetermined distance. A develop process is performed for forming openings in the photoresist layer.