Semiconductor Reticle Protrusion for Lithographic Bridging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optical proximity effects during lithographic processes lead to issues such as shortened line features, non-uniform critical dimensions, and bridging between tightly grouped features on semiconductor wafers, due to light diffraction and interference, which existing correction methods struggle to fully address without compromising the etch stop layer removal.
Innovation Solution
A modified reticle pattern with a body portion and a protruding portion is introduced, where the protruding portion ensures sufficient etching of ultra-thick metal layers while maintaining separation to prevent bridging and ensure complete removal of the etch stop layer, using computer algorithms for optical proximity corrections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional lithographic processes are used, then manufacturing simplicity is maintained, but optical proximity effects cause shortened line features, non-uniform critical dimensions, and bridging between tightly grouped features
Solution Approach 1:
The reticle pattern is divided into a body portion and a protruding portion. The protruding portion is a separate structural element that extends from the body portion to address optical proximity effects, allowing the pattern to be segmented into functional regions that correct dimensional variations and prevent bridging between tightly grouped features
Solution Approach 2:
The protruding portion is designed in advance into the reticle pattern to pre-compensate for optical proximity effects before lithographic exposure. This preliminary structural adjustment ensures that the exposed features on the wafer achieve uniform critical dimensions and proper spacing, preventing bridging issues before they occur
2Reliability
If the protruding portion is added to the reticle pattern, then etch stop layer removal is ensured and bridging is prevented, but the reticle design becomes more complex
Solution Approach 1:
The protruding portion is strategically positioned and dimensioned to locally address specific problems: it extends into the space between tightly grouped features to prevent bridging, and its geometry is optimized to ensure complete etch stop layer removal in critical areas. This localized structural modification targets reliability issues without requiring complete redesign of the entire reticle pattern
3Manufacturing precision
If optical proximity corrections are applied, then feature size accuracy is improved, but light diffraction and interference effects are not fully eliminated
Solution Approach 1:
The protruding portion is designed to preemptively counteract the harmful effects of light diffraction and interference. By extending into the gap between tightly grouped features, it creates a physical barrier that prevents optical coupling and reduces diffraction effects, thereby maintaining critical dimension uniformity without requiring additional optical correction steps
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 effectively mitigates optical proximity effects, ensuring accurate and uniform feature sizes and preventing bridging or disconnection between conductive layers, thereby enhancing the manufacturing quality of semiconductor devices.
Implementation Method 1
Optical proximity effects during lithographic processes lead to issues such as shortened line features, non-uniform critical dimensions, and bridging between tightly grouped features on semiconductor wafers, due to light diffraction and interference
Implementation Method 2
Optical proximity effects during lithographic processes lead to issues such as shortened line features, non-uniform critical dimensions, and bridging between tightly grouped features on semiconductor wafers, due to light diffraction and interference
Data Source
AI summary
Some embodiments of the present disclosure provide a semiconductive device. The semiconductive device includes a first conductive layer and a second conductive layer above the first conductive layer. The second conductive layer includes a first portion and a second portion protruding from the first portion. A via structure is under the second conductive layer and on top of the first conductive layer. The via structure is substantially aligned vertically with the second portion.