TSV Liner Structure With Polish-Stop Layer for CMP Control
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Solution Overview
Problem
In existing Through Silicon Via (TSV) technology, the polishing rate and thickness cannot be effectively controlled, leading to excessive polishing and potential damage to the conductive layer during the manufacturing process of semiconductor structures.
Innovation Solution
A method is introduced that involves forming a liner layer with polish-stop layers, comprising silicon nitride or silicon carbon nitride, which allows for precise control of the polishing process by adjusting the polishing rate based on resistance changes, preventing excessive polishing and ensuring accurate filling of the TSV with a conductive layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional polishing is used after metal material is filled in TSV, then the TSV can be processed, but the polishing rate and thickness cannot be effectively controlled, leading to excessive polishing
Solution Approach 1:
A polish-stop layer is formed on the sidewall and bottom of the TSV before the conductive layer is deposited. This preliminary structure serves as a predetermined stopping point during polishing, enabling precise control of polishing thickness and preventing excessive polishing that would damage the conductive layer.
Solution Approach 2:
The polish-stop layer acts as an intermediary element between the polishing process and the conductive layer. It provides a mechanical barrier that mediates the polishing action, allowing the polishing head to stop at a predetermined location and protect the underlying conductive layer from being polished away.
2Ease of manufacture
If polishing is performed without a polish-stop layer, then the process is simpler, but excessive polishing occurs and the conductive layer may be damaged
Solution Approach 1:
The polish-stop layer is formed in advance during the TSV structure preparation, before metal filling. This preliminary action integrates the thickness control function into the existing manufacturing flow without requiring complex real-time monitoring or multiple polishing steps, maintaining ease of manufacture while achieving precise thickness control.
3Productivity
If the TSV depth is reduced to less than base thickness, then vertical interconnect stacking can be implemented, but the liner layer and conductive layer formation becomes more critical
Solution Approach 1:
The liner layer and polish-stop layer are formed on the TSV sidewall and bottom before conductive layer deposition. This preliminary preparation ensures that when the conductive layer is subsequently filled, it adheres properly to the prepared surfaces and can be precisely controlled, which is critical for shallow TSV structures where the conductive layer occupies a larger proportion of the overall structure.
Solution Approach 2:
The liner layer provides localized protection and adhesion enhancement specifically on the TSV sidewall and bottom surfaces, while the polish-stop layer provides localized thickness control at the polishing interface. These localized quality enhancements ensure precise conductive layer formation in the critical TSV region without affecting the entire base structure.
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 enhances the precision and efficiency of the polishing process, preventing damage to the conductive layer and ensuring high-density integration in semiconductor structures by allowing real-time adjustment of the polishing rate, thereby improving the manufacturing process.
Implementation Method 1
Each of the first polish-stop layer and the second polish-stop layer comprises a silicon nitride layer or a silicon carbon nitride layer
Data Source
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AI summary
A method for manufacturing a semiconductor structure, comprising: providing a base; forming a Through Silicon Via (TSV) in the base, with a depth of the TSV being less than a thickness of the base; and forming a liner layer on a sidewall and the bottom of the TSV, and forming a conductive layer in the TSV, the liner layer comprising a polish-stop layer.