Semiconductor Spacer Structure for Self-Aligned Pattern Transfer
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Solution Overview
Problem
The semiconductor industry faces challenges in forming reliable semiconductor devices at increasingly smaller sizes due to the complexity and difficulty of fabrication processes as feature sizes decrease.
Innovation Solution
A method involving the formation of spacers and filling layers in trenches on a substrate, with specific processes for removing and re-forming spacers to improve alignment accuracy and yield, and transferring patterns to underlying layers, is employed to create semiconductor device structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If feature sizes are decreased to increase functional density, then production efficiency and cost are improved, but fabrication process complexity and difficulty increase
Solution Approach 1:
The fabrication process is divided into multiple sequential steps including forming first spacers, selectively removing portions, forming filling layers, and forming second spacers. This segmentation allows each step to be optimized independently, managing the overall process complexity while achieving smaller feature sizes and improved functional density.
Solution Approach 2:
Filling layers are formed in advance to cover and protect first spacers before the second spacers are formed. This preliminary protective action prevents damage to previously formed structures during subsequent processing steps, thereby managing fabrication complexity while enabling continued scaling.
2Productivity
If feature sizes are decreased to increase functional density, then production efficiency and cost are improved, but manufacturing precision requirements increase
Solution Approach 1:
Filling layers serve as intermediary protective structures between the first and second spacers. These filling layers improve alignment accuracy by providing a stable reference structure and protecting the first spacers from damage during the formation of second spacers, enabling precise manufacturing at smaller feature sizes.
Solution Approach 2:
The filling layers automatically form to cover the first spacers through conformal deposition processes, creating self-aligned protective structures. This self-service mechanism improves alignment accuracy without requiring additional alignment steps, thereby maintaining production efficiency while enabling smaller feature sizes.
3Productivity
If feature sizes are decreased to increase functional density, then production efficiency and cost are improved, but device reliability becomes more difficult to ensure
Solution Approach 1:
Filling layers are formed in advance to provide protective cushioning to the first spacers before subsequent processing steps. This prior protection prevents damage to critical structures during the formation of second spacers and pattern transfer processes, ensuring device reliability while maintaining the ability to fabricate smaller features with improved production efficiency.
Data Source
AI summary
A method for forming a semiconductor device structure is provided. The method includes forming a first spacer over a substrate. The method includes partially removing the first spacer to form a gap dividing the first spacer into a first part and a second part. The method includes forming a filling layer covering a first top surface and a first sidewall of the first spacer. The filling layer and the first spacer together form a strip structure. The method includes forming a second spacer over a second sidewall of the strip structure. The method includes forming a third spacer over a third sidewall of the second spacer. The third spacer is narrower than the second spacer.