Dummy Gate Structure Height Uniformity in Semiconductor Devices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing dummy gate structures in semiconductor devices often have height differences from actual gate structures, leading to uneven insulation layer heights and potential breakdown voltage issues due to the formation on isolation layers with lower heights than the substrate surface.
Innovation Solution
A semiconductor device design where a dummy gate structure is formed on an active region with the same height as the gate structures, using the same materials, and including a wider control gate to increase total gate density and prevent breakdown voltage reduction, while an impurity region is added to prevent channel formation under the dummy gate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the dummy gate structure is formed on the isolation layer to reduce cell interference, then the effective field oxide height is lowered, but the height difference between the dummy gate structure and actual gate structures increases
Solution Approach 1:
The patent changes the formation position parameter of the dummy gate structure from the isolation layer to the active region. This parameter change allows the dummy gate structure to be formed at the same height as the actual gate structures, eliminating the height difference while still achieving cell interference reduction through the impurity region configuration.
2Reliability
If the isolation layer is formed lower than the substrate surface to reduce effective field oxide height, then cell interference is reduced, but the dummy gate structure height becomes different from gate structure height
Solution Approach 1:
The patent applies local quality by forming an impurity region in a specific location (adjacent to the lower portion of the isolation layer) to prevent channel formation. This allows the dummy gate structure to be formed on the active region at the same height as gate structures, maintaining insulation layer uniformity while still achieving cell interference reduction through the localized impurity region.
3Manufacturing precision
If the dummy gate structure is formed to have the same height as gate structures, then insulation layer height uniformity is improved, but the effective field oxide height may increase
Solution Approach 1:
The patent changes the formation position parameter of the dummy gate structure from the isolation layer to the active region. This allows the dummy gate structure to have the same height as actual gate structures, improving insulation layer uniformity. The impurity region is configured to prevent channel formation, maintaining breakdown voltage despite the position change.
Solution Approach 2:
The impurity region acts as an intermediary element that prevents channel formation between the dummy gate structure and the substrate. This mediator allows the dummy gate structure to be formed at the same height as gate structures without compromising breakdown voltage, as the impurity region blocks potential leakage paths.
4Manufacturing precision
If the dummy gate structure is formed on the active region with the same height, then height difference is reduced, but channel formation under the dummy gate may occur
Solution Approach 1:
The patent applies preliminary anti-action by forming an impurity region adjacent to the lower portion of the isolation layer before completing the dummy gate structure formation. This impurity region preemptively prevents channel formation under the dummy gate structure, allowing the dummy gate to be formed at the same height as gate structures without creating harmful leakage paths.
Data Source
AI summary
A semiconductor device and method of manufacturing a semiconductor device include a plurality of first active regions and a second active region being formed on a substrate. The second active region is formed between two of the first active regions. A plurality of gate structures is formed on respective first active regions. A dummy gate structure is formed on the second active region, and a first voltage is applied to the dummy gate structure.