Semiconductor Substrate Polishing via Multi-Angle Ion Implantation
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Solution Overview
Problem
Existing semiconductor substrate polishing methods, such as mechanical abrasion and chemical-mechanical polishing (CMP), are limited in effectively improving surface roughness and structural uniformity.
Innovation Solution
A method involving multiple ion implantations with varying orientations, followed by selective removal of the modified upper substrate portion, to achieve improved surface smoothing and structural refinement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If mechanical abrasion or chemical-mechanical polishing (CMP) is used, then surface roughness is reduced, but structural uniformity and surface smoothness are not effectively improved
Solution Approach 1:
The patent replaces mechanical abrasion and chemical-mechanical polishing with an ion implantation process. Ions are implanted into the semiconductor substrate at controlled energies and angles to modify the upper portion's structure, creating a more uniform and smooth surface without the limitations of mechanical or chemical methods. This substitution enables effective improvement of both surface roughness and structural uniformity.
Solution Approach 2:
The patent employs multiple ion implantations with varying parameters including different implantation energies (e.g., 50 keV, 100 keV, 200 keV), different angles (e.g., 0°, 45°, 60°), and different ion types (e.g., Helium, Neon, Argon). By systematically changing these parameters across multiple implantation steps, the method achieves superior surface smoothing and structural uniformity compared to conventional single-step approaches.
2Manufacturing precision
If multiple ion implantations with different orientations are performed, then surface smoothness and structural uniformity are improved, but process complexity increases
Solution Approach 1:
The patent divides the surface modification process into multiple discrete ion implantation steps, each with specific orientations and energies. For example, the method may include a first implantation at 0° with 50 keV energy, a second at 45° with 100 keV, and a third at 60° with 200 keV. This segmentation allows precise control over the modified layer's structure and properties, achieving superior surface smoothness while maintaining process manageability through systematic parameter variation.
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 effectively reduces the surface roughness and structural irregularities of the semiconductor substrate, enhancing its smoothness and uniformity.
Implementation Method 1
a) a step of multiple implantations of ions from an upper surface of the substrate, to modify the material of an upper portion of the substrate
Implementation Method 2
the method further comprises, after step a), a step of solid phase recrystallization of a lower portion of said upper portion of the substrate
Implementation Method 3
at step b), the selective removal of the upper portion of the substrate is carried out by a method of thermal etching by means of a gaseous mixture
Data Source
AI summary
A method of polishing a semiconductor substrate, including: a) a step of multiple implantations of ions from an upper surface of the substrate, to modify the material of an upper portion of the substrate, the multiple implantation step comprising a plurality of successive implantations under different respective implantation orientations; and b) a step of selective removal of the upper portion of the substrate.