Semiconductor Device Dummy Pattern Homogeneity
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Solution Overview
Problem
In semiconductor technology, particularly at nodes 22 nm and below, improper design of dummy patterns can lead to overlay defects, incompatibility with other processes, and unreliable circuit simulations due to differences in shape and layout between dummy devices and transistors on stress layers, affecting yield and reliability.
Innovation Solution
A semiconductor device design where the core and dummy devices share the same shape and stress layer material, with stress layers formed of embedded silicon carbide or silicon germanium, disposed uniformly on opposing sides of gates, enhancing compatibility and predictability with other semiconductor processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If dummy patterns are designed with different shape and layout from transistors on stress layer, then dummy devices can be fabricated to ensure uniform device density, but overlay defects and processing incompatibility occur during subsequent processing
Solution Approach 1:
The patent applies homogeneity by designing the dummy device to have the same shape, layout, and stress layer configuration as the core transistor. Specifically, both the dummy device and core device include stress layers (e.g., embedded silicon carbide or silicon germanium) disposed on opposing sides of the gate in identical arrangements. This homogeneous design ensures that both device types respond uniformly to subsequent processing steps, eliminating overlay defects while maintaining uniform device density across the semiconductor substrate.
2Manufacturing precision
If dummy patterns are designed with different shape and layout from transistors on stress layer, then dummy devices can be fabricated to prevent pattern mismatch, but incompatibility with other semiconductor processes occurs
Solution Approach 1:
The patent applies universality by designing the dummy device to be structurally identical to the core device, including identical stress layer materials (such as embedded silicon carbide for NMOS or silicon germanium for PMOS), identical gate configurations, and identical overall geometry. This universal design allows the dummy device to serve multiple functions: maintaining uniform device density, preventing pattern mismatch, and ensuring compatibility with all subsequent semiconductor processing steps that are optimized for the core device structure.
3Manufacturing precision
If dummy patterns are designed with different shape and layout from transistors on stress layer, then dummy devices can be fabricated, but unreliable circuit simulation models result
Solution Approach 1:
The patent applies copying by creating the dummy device as an exact structural copy of the core device. The dummy device replicates all critical geometric and material characteristics of the core transistor, including the stress layer composition (embedded silicon carbide or silicon germanium), layer thicknesses, gate dimensions, and overall device footprint. This precise copying ensures that circuit simulation models can accurately predict the electrical behavior of both core and dummy devices, as the dummy device provides a reliable reference that matches the actual transistor structure.
Data Source
AI summary
A semiconductor device is provided. The semiconductor device includes a semiconductor substrate, and a core device and a dummy device disposed on the semiconductor substrate. The core device includes a first gate disposed on the semiconductor substrate and a first stress layer disposed on opposing sides of the first gate. The dummy device includes a second gate disposed on the semiconductor substrate and a second stress layer disposed on opposing sides of the second gate.