Spacer Patterning for Different Critical Dimensions at Uniform Pitch
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Solution Overview
Problem
The Self-Aligned Double Patterning (SADP) technique in microelectronics fails to produce patterns with varying critical dimensions on a substrate, as all spacers formed have the same critical dimension, limiting the ability to create patterns with different dimensions and pitches, and requires precise control over spacer fusion, which is restrictive.
Innovation Solution
A method is developed to form patterns with different critical dimensions by creating first and second sacrificial patterns with distinct dimensions, followed by the conformal deposition and anisotropic etching of structural layers to form spacers, allowing for the selective removal of sacrificial patterns and achieving the desired critical dimension difference using Atomic Layer Deposition (ALD) techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If SADP technique is used to form patterns, then pattern density is doubled, but all patterns have the same critical dimension and pitch
Solution Approach 1:
The substrate is divided into multiple regions, each with different sacrificial pattern critical dimensions. This segmentation allows different regions to produce patterns with different critical dimensions while maintaining the same pitch, resolving the contradiction between pattern density and critical dimension variation.
Solution Approach 2:
Different regions of the substrate are assigned different sacrificial pattern dimensions tailored to local requirements. This local quality approach enables each region to have optimized pattern characteristics while maintaining overall process compatibility, allowing both high density and dimension variation.
2Adaptability or versatility
If multiple sacrificial patterns with different critical dimensions are formed, then patterns with different critical dimensions can be achieved, but pitch control becomes more difficult
Solution Approach 1:
The self-aligned spacer formation process automatically ensures uniform pitch between patterns. The spacer width is determined by the sacrificial pattern dimensions and the conformal deposition thickness, eliminating the need for separate pitch control steps and maintaining manufacturing precision while enabling critical dimension variation.
3Manufacturing precision
If structural layers are conformally deposited to form spacers, then spacer thickness is controlled, but all spacers have the same critical dimension
Solution Approach 1:
Sacrificial patterns with different critical dimensions are formed in different regions before the conformal deposition step. This preliminary action ensures that when the structural layer is deposited conformally, spacers formed on different sacrificial patterns will have different critical dimensions while maintaining controlled thickness through the deposition process.
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 method enables the formation of patterns with varying critical dimensions while maintaining identical pitches, providing greater control over critical dimension differences and improving the precision and efficiency of pattern formation in microelectronics.
Implementation Method 1
conformal deposition of a first structural layer in the first and second regions
Implementation Method 2
the anisotropic etching of the first structural layer
Implementation Method 3
conformal deposition of a second structural layer in the first and second regions
Implementation Method 4
the anisotropic etching of the second structural layer
Implementation Method 5
removal of the second structural layer in the first region
Implementation Method 6
selective removal of the first and second sacrificial motifs from the first and second spacers
Data Source
Figure 1(a)~2(e)
Figure 3A~3E
Figure 3F~3I
AI summary
One aspect of the invention relates to a method for forming a first group of patterns and a second group of patterns on a substrate surface, the first group of patterns being located in a first region of the substrate surface and the second group of patterns being located in a second region of the substrate surface, the method comprising the following steps: - formation of a first sacrificial pattern and a second sacrificial pattern on the substrate, the first sacrificial pattern being located in the first region and having a first critical dimension, the second sacrificial pattern being located in the second region and having a second critical dimension strictly smaller than the first critical dimension; - formation of first spacers in the first region, on flanks of the first sacrificial pattern, and in the second region, on flanks of the second sacrificial pattern;- formation of a second spacer on one flank of each first spacer located in the second region, the formation of the second spacers including in particular a substep of conformal deposition of a second structural layer in the first and second regions, the second structural layer having a thickness equal to the difference between the first critical dimension and the second critical dimension; - selective removal of the first and second sacrificial motifs from the first and second spacers.