Semiconductor Contact Structure Using Sacrificial Backside Replacement
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Solution Overview
Problem
Current semiconductor devices face challenges in achieving high reliability, high speed, and multifunctionality due to complex and highly integrated structures, which are difficult to manufacture efficiently while maintaining power, performance, area, and cost (PPAC) requirements.
Innovation Solution
A method for manufacturing a semiconductor device involves forming a sacrificial contact pattern on a buffer substrate, followed by the creation of a base layer and active patterns, with a gate electrode and source/drain patterns that overlap the sacrificial contact pattern, allowing for the exposure and replacement of the sacrificial contact to form lower source/drain contacts and backside wiring patterns, enhancing integration and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If complex and highly integrated structures are used to achieve high reliability, high speed, and multifunctionality, then device performance is improved, but manufacturing difficulty and process complexity increase
Solution Approach 1:
The patent applies preliminary action by forming the sacrificial contact pattern before the active pattern and gate electrode. This pre-positioned sacrificial structure guides subsequent manufacturing steps, enabling self-aligned formation of lower source/drain contacts without requiring complex alignment processes, thus improving manufacturing efficiency while maintaining device reliability
Solution Approach 2:
The sacrificial contact pattern serves as an intermediary element that facilitates the formation of lower source/drain contacts. This temporary structure enables precise positioning and direct connection between the source/drain patterns and substrate, simplifying the manufacturing process while ensuring reliable electrical connections in the final device
2Speed
If complex and highly integrated structures are used to achieve high speed and multifunctionality, then device performance is improved, but structural complexity increases
Solution Approach 1:
The patent segments the contact structure into upper source/drain contacts and lower source/drain contacts, with the lower contacts formed through the sacrificial pattern replacement method. This segmentation allows independent optimization of each contact level, reducing overall structural complexity while enabling high-speed performance through direct, low-resistance connections
3Ease of manufacture
If conventional contact formation methods are used, then manufacturing process is simpler, but voids in contacts increase causing voltage drops
Solution Approach 1:
The sacrificial contact pattern enables self-aligned formation of lower source/drain contacts, where the contact holes are automatically positioned by the sacrificial structure itself. This self-service mechanism eliminates the need for separate alignment processes while ensuring complete fill and void-free contacts, improving electrical connection reliability without complicating the manufacturing process
Data Source
AI summary
A method for manufacturing a semiconductor device includes providing a buffer substrate, forming a sacrificial contact film on the buffer substrate, forming a sacrificial contact pattern by patterning the sacrificial contact film, forming a first base layer on the buffer substrate that surrounds the sacrificial contact pattern, forming an active pattern on the first base layer and the sacrificial contact pattern that extends in a first direction, forming a gate electrode on the active pattern extending in a second direction intersecting the first direction, forming a source/drain pattern on a side surface of the gate electrode for connection to the active pattern. The source/drain pattern overlaps the sacrificial contact pattern in a third direction intersecting the first and second directions. The sacrificial contact pattern is exposed by removing the buffer substrate. A lower source/drain contact is formed for connection to the source/drain pattern by replacing the exposed sacrificial contact pattern.