Semiconductor Wiring Layout With Self-Aligned Small Via Formation
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Solution Overview
Problem
The challenge in manufacturing semiconductor devices lies in forming small vias that accurately align with transmission lines, as current methods struggle to precisely locate and fabricate these structures, leading to manufacturing difficulties.
Innovation Solution
The approach involves forming transmission lines and vias using a multi-step process with phototools and stop layers, where overlapping patterns define regions for cavity formation, allowing for the creation of vias that are integral with the transmission lines, enabling accurate alignment and reduced manufacturing complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional via formation methods are used, then the manufacturing process is simple, but the via size cannot be sufficiently small and alignment precision is poor
Solution Approach 1:
The via formation process is segmented into multiple lithography and etching steps. First, a via mask is formed and a first etch creates a via opening. Then, a trench mask is formed and a second etch creates a trench. This segmentation allows independent optimization of via size and alignment precision without compromising process simplicity
Solution Approach 2:
The via opening is formed in advance before the trench formation. The via mask and first etch step prepare the via opening preliminarily, establishing a precise alignment reference before the trench mask and second etch step create the trench. This preliminary action ensures that the final conductor structure achieves both small via size and high alignment precision
2Productivity
If separate filling operations are used for trench and via, then the process is simpler to control, but productivity is reduced due to multiple deposition steps
Solution Approach 1:
The trench filling and via filling operations are merged into a single conductor deposition step. The conductor material is deposited simultaneously to fill both the trench and the via opening, eliminating the need for separate deposition processes. This merging significantly improves productivity while the underlying segmented etching process maintains controllability
Solution Approach 2:
The conductor structure formed is composite in nature, filling both the trench and via opening in a single operation. This composite filling approach allows the deposition process to handle multiple structures simultaneously, improving efficiency without requiring complex separate deposition sequences
Data Source
AI summary
Apparatus and methods are disclosed, including transistors, semiconductor devices and systems. Example semiconductor devices and methods include a first transmission line and a second transmission line located over one another. A via is shown connecting the first transmission line and a second transmission line wherein a first side of the via and a side of the second transmission line are coplanar. A via is also shown connecting the first transmission line and a second transmission line wherein the second transmission line tapers downward from a line width to a via width.