Self-Aligned Landing Pad via Fence Structure and Corner Etching
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Solution Overview
Problem
Current semiconductor manufacturing methods face challenges in achieving stable contact between conductors and ensuring process margins, particularly in forming landing pads with precise alignment and reduced lithography processes for highly integrated and minute patterns.
Innovation Solution
The method involves forming a gate line and impurity region on a substrate, creating an insulating film pattern with a through-hole, applying a barrier metal layer, and using a mask pattern for photolithography to form a landing pad, with self-alignment facilitated by a previously patterned fence, and partial etching of the barrier metal layer to remove corners and ensure process margins.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional lithography processes are used to form landing pads, then alignment precision can be maintained, but manufacturing complexity and cost increase
Solution Approach 1:
The patent applies preliminary action by pre-forming the fence structure before landing pad formation. The fence is created as a reference structure that defines the position where landing pads will subsequently be formed, eliminating the need for separate alignment lithography processes. This preliminary structuring enables self-alignment in later manufacturing steps.
Solution Approach 2:
The patent implements self-service through self-aligned landing pad formation where the landing pads automatically align to the pre-formed fence structure. The fence serves as a self-referencing guide that enables subsequent materials to align without external alignment tools or additional lithography steps, making the system self-aligning.
2Manufacturing precision
If complete lithography processes are performed for landing pad formation, then alignment accuracy is ensured, but manufacturing time and cost increase
Solution Approach 1:
The fence structure is formed in advance as a permanent reference feature that eliminates the need for subsequent alignment lithography. This preliminary action of creating the fence structure before landing pad formation removes the time-consuming alignment steps while maintaining precision through the physical presence of the fence as a guide.
Solution Approach 2:
The patent extracts and removes the alignment lithography step from the manufacturing process by using the pre-formed fence as a physical alignment reference. Instead of performing complete lithography processes for alignment, the method takes out the alignment function and achieves it through the existing fence structure, reducing process time.
3Productivity
If landing pads are formed without process margin considerations, then manufacturing steps are reduced, but contact stability deteriorates
Solution Approach 1:
The patent applies local quality by selectively removing corners of the barrier metal layer at specific locations where process margins are needed. Instead of uniformly reducing the barrier metal layer across the entire structure, only the corner regions are removed to provide adequate process margins for contact stability while maintaining the integrity and size of the main landing pad structure.
Solution Approach 2:
The corner removal of the barrier metal layer serves as a preliminary anti-action to prevent potential contact instability. By proactively removing corners that could cause stress concentration or alignment issues, the method prevents future contact problems before they occur, ensuring reliable contact stability.
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 allows for cost-effective self-alignment of landing pads during semiconductor manufacturing, reducing the need for extensive lithography processes and ensuring adequate process margins, thereby improving the manufacturing efficiency and precision of semiconductor devices.
Implementation Method 1
forming a landing pad by performing a photolithography process using the first mask pattern
Implementation Method 2
removing corners by partially etching the barrier metal layer
Data Source
AI summary
Methods for manufacturing a semiconductor device include forming a gate line extending in a first direction in a substrate, and an impurity region on a side surface of the gate line, forming an insulating film pattern on the substrate, the insulating film pattern extending in the first direction and comprising a first through-hole that is configured to expose the impurity region, forming a barrier metal layer on the first through-hole, forming a conductive line contact that fills the first through-hole and that is electrically connected to the impurity region, forming a first mask pattern on the conductive line contact and the insulating film pattern, the first mask pattern extending in a second direction that is different from the first direction and the first mask pattern comprising a first opening, and removing corners of the barrier metal layer by partially etching the barrier metal layer.