Particle Film Planarization for Semiconductor Device Structures
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Solution Overview
Problem
Conventional chemical-mechanical polishing (CMP) processes for semiconductor device fabrication face challenges in efficiently forming planar surfaces, as they often require complex and costly methods to differentiate between elevated and recessed regions, leading to material removal inefficiencies and stress on fragile device structures.
Innovation Solution
A method involving the formation of a particle film with discrete particles on the non-planar surface, which is then subjected to a CMP process, providing protection to recessed regions and facilitating efficient planarization with reduced processing complexity and stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If protective additives are incorporated into the polishing slurry to remove elevated regions faster than recessed regions, then material removal selectivity is improved, but the protective additives are physically removed from recessed regions when they are relatively large, limiting the protection provided
Solution Approach 1:
The patent introduces an intermediary protective film formed from protective additives that mediates between the polishing slurry and the semiconductor material. This film selectively protects recessed regions during CMP by adhering more strongly to elevated regions where it is removed by the polishing action, while remaining on recessed regions to prevent their removal. The film acts as a temporary intermediary layer that enables selective material removal without directly exposing the recessed regions to the abrasive slurry.
Solution Approach 2:
The patent employs parameter changes by controlling the concentration, molecular weight, and chemical composition of protective additives in the polishing slurry. By adjusting these parameters, the protective film's adhesion strength and thickness are optimized to ensure it remains on recessed regions during CMP. The slurry's pH, abrasive particle size, and chemical reactivity are also tuned to work synergistically with the protective film for selective material removal.
2Manufacturing precision
If a continuous solid film is formed over the surfaces of the material prior to CMP to protect recessed regions, then material removal selectivity is improved, but the process becomes complex and costly requiring multiple processing acts and materials
Solution Approach 1:
The patent merges the protective film formation and material removal functions into a single integrated CMP process. Instead of separate steps for forming a protective coating and then performing CMP, the protective additives are incorporated directly into the polishing slurry, allowing the protective film to form in-situ during the CMP process itself. This consolidation eliminates multiple processing acts and reduces overall process complexity.
Solution Approach 2:
The protective film is self-forming during the CMP process through the action of protective additives in the slurry. The film automatically adheres to elevated regions and is removed by the polishing action, while simultaneously protecting recessed regions. This self-regulating mechanism eliminates the need for external coating equipment or separate film formation steps, simplifying the overall manufacturing process.
3Manufacturing precision
If a continuous solid film is formed over the surfaces of the material prior to CMP to protect recessed regions, then material removal selectivity is improved, but significant downward force is required to remove the solid film, applying undesirable stress on the fragile semiconductor device structure
Solution Approach 1:
The protective film in the patent is dynamic rather than static, continuously forming and reforming during the CMP process. As the polishing pad contacts the surface, the film forms on elevated regions and is dynamically removed by the mechanical action, while remaining stable on recessed regions. This dynamic behavior allows the film to be removed without applying significant additional downward force, reducing stress on the fragile semiconductor structure.
Solution Approach 2:
The protective film undergoes periodic formation and removal cycles during CMP. It forms continuously during the polishing process, is periodically removed from elevated regions by the abrasive action, and reforms as the pad continues to move across the surface. This periodic action enables the film to be removed in small increments rather than requiring a single high-force removal step, minimizing stress on the device 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 planarization efficiency by selectively protecting recessed regions during CMP, reducing material usage and processing steps, and minimizing stress on the semiconductor device structure, thereby improving the formation of planar surfaces with fewer acts and materials.
Implementation Method 1
forming a particle film comprising a plurality of discrete particles on a non-planar surface... The particle film may include a plurality of discrete particles directly attached to the non-planar surface
Implementation Method 2
The chemically reactive material chemically modifies at least some of the material to promote removal of the material by the abrasive material
Implementation Method 3
The abrasive material and the rotating polishing pad physically modify and remove at least some portions of the material
Data Source
AI summary
A method of forming a planar surface for a semiconductor device structure. The method comprises forming a particle film comprising a plurality of discrete particles on a non-planar surface of a semiconductor device structure. The semiconductor device structure is subjected to at least one chemical-mechanical polishing process after forming the particle film on the non-planar surface of the semiconductor device structure. Methods of forming a semiconductor device structure are also described.