Mask Layer Patterning With Organic Compensation for RIE Lag
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Solution Overview
Problem
Existing semiconductor fabrication methods face challenges in patterning mask layers due to reactive-ion etch (RIE) lag, which causes openings of different widths and shapes to be etched differently, leading to inefficiencies and inconsistencies.
Innovation Solution
A method involving the use of a photoresist layer to compensate for etch rate differences, combined with thermal treatment or additional etch processes, to pattern mask layers with varying critical dimensions, ensuring uniformity and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If reactive-ion etching is used to pattern mask layers with different critical dimensions, then the etching process can be performed efficiently, but RIE lag causes openings of different widths to be etched differently, leading to manufacturing precision degradation
Solution Approach 1:
An organic layer is deposited over the patterned second mask layer before etching the first mask layer. This organic layer serves as a preliminary protective barrier that compensates for RIE lag effects during the etching process, ensuring more uniform opening widths across different regions with varying critical dimensions.
Solution Approach 2:
The organic layer acts as an intermediary between the etching process and the first mask layer. It modulates the etching rate by providing a protective effect that compensates for the width-dependent etching variations caused by RIE lag, thereby achieving more consistent patterning results.
2Manufacturing precision
If multiple etching processes are used to compensate for RIE lag, then manufacturing precision improves, but process complexity increases
Solution Approach 1:
The organic layer serves as a single intermediary that replaces the need for multiple separate etching processes. By depositing this layer before etching, the method achieves compensation for RIE lag effects in one unified process rather than requiring multiple sequential etching steps with different parameters.
Solution Approach 2:
The method changes the physical-chemical parameters of the etching system by introducing the organic layer, which alters the etching rate profile. This parameter change enables uniform etching of openings with different widths without requiring multiple process steps, thus reducing overall process complexity.
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
The method effectively addresses RIE lag by uniformly etching mask layers with different widths, enhancing the precision and consistency of semiconductor fabrication processes.
Implementation Method 1
removing the organic layer over the third and fourth regions of the substrate includes performing a thermal treatment on the organic layer, the thermal treatment disintegrating the organic layer
Implementation Method 2
exposing a coating of photoresist comprising a radiation-sensitive material to a pattern of actinic radiation to define a relief pattern
Implementation Method 3
transferring a pattern of the patterned first mask layer to the target layer
Implementation Method 4
transferring a pattern of the patterned first mask layer to the target layer
Data Source
AI summary
A method includes forming a first mask over a substrate, forming a second mask over the first mask, and patterning the second mask to form a patterned second mask. The patterned second mask includes first, second, third, and fourth openings over a first, second, third, and fourth regions of the substrate, respectively. The method further includes forming an organic layer over the patterned second mask, forming a photoresist over the organic layer and patterned second mask, patterning the photoresist to expose the organic layer and the patterned second mask over the first and second regions, etching the organic layer and the first mask to extend the first and second openings into the first mask, removing the organic layer over the third and fourth regions, and etching the first mask to extend the first, second, third, and fourth openings through the first mask and form a patterned first mask.