Chemical Planarization via Selective Dissolution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current chemical mechanical polishing (CMP) methods for semiconductor surfaces face challenges such as yield reduction due to polishing damage from abrasive grains and inefficiencies in achieving high flatness, particularly for small features, where scratches occur and etch-pits degrade the surface.
Innovation Solution
A chemical planarization method involving the formation of a surface layer on the semiconductor film that binds or adsorbs along irregularities, allowing selective dissolution of convex portions over concave portions using a processing solution without abrasive grains, thereby achieving high flatness and minimizing scratches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If chemical mechanical polishing (CMP) with abrasive grains is used for planarization, then the surface flatness is improved, but polishing damage (scratches) occurs causing yield reduction
Solution Approach 1:
The patent replaces the mechanical polishing action with abrasive grains with a chemical dissolution process. A processing solution chemically dissolves the convex portions of the film surface, achieving planarization without mechanical contact that causes scratches. This substitution of mechanical action with chemical action resolves the contradiction between achieving flatness and avoiding polishing damage.
Solution Approach 2:
The patent applies local quality by making the dissolution rate spatially non-uniform across the film surface. The processing solution selectively dissolves convex portions at a higher rate than concave portions, creating a local difference in dissolution degree that progressively flattens the surface while avoiding uniform damage across the entire surface.
2Manufacturing precision
If conventional CMP method is used, then planarization is achieved, but scratches occur on the surface reducing yield
Solution Approach 1:
The patent eliminates the mechanical polishing system that causes scratches by using chemical dissolution instead. The processing solution chemically removes material from convex portions without the mechanical contact that creates scratches, thereby maintaining planarization capability while preserving yield by avoiding scratch-induced defects.
3Object-affected harmful factors
If chemical polishing without physical agent is used, then scratches are suppressed, but dissolution uniformity is poor causing etch-pits
Solution Approach 1:
The patent implements local quality by creating spatial variation in dissolution rate across the film surface. The processing solution is formulated to dissolve convex portions at a different rate than concave portions, with the dissolution degree being higher for convex portions. This local difference in dissolution behavior achieves uniform planarization without creating etch-pits, resolving the contradiction between scratch suppression and dissolution uniformity.
Solution Approach 2:
The patent changes the dissolution parameters by controlling the composition and properties of the processing solution, as well as the contact conditions between the film and solution. By adjusting parameters such as solution chemistry, temperature, and contact pressure, the dissolution rate is optimized to be selective for convex portions while maintaining overall uniformity, preventing etch-pit formation.
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 suppresses scratch generation and enhances planarization efficiency by selectively dissolving convex portions, achieving high accuracy and utility in semiconductor processing without mechanical damage, applicable to various film materials like SiO2.
Implementation Method 1
The surface layer binds to or adsorbs onto the to-be-processed film along the irregularity to suppress dissolution of the to-be-processed film
Implementation Method 2
planarizing the to-be-processed film in a processing solution dissolving the to-be-processed film, by rotating the to-be-processed film and a processing body while the to-be-processed film contacting the processing body via the surface layer, removing the surface layer on convex portions of the irregularity while leaving the surface layer on concave portions of the irregularity and making dissolution degree of the convex portions larger than dissolution degree of the concave portions
Data Source
AI summary
According to one embodiment, a method is disclosed for chemical planarization. The method can include forming a surface layer on a to-be-processed film having irregularity. The surface layer binds to or adsorbs onto the to-be-processed film along the irregularity to suppress dissolution of the to-be-processed film. The method can include planarizing the to-be-processed film in a processing solution dissolving the to-be-processed film, by rotating the to-be-processed film and a processing body while the to-be-processed film contacting the processing body via the surface layer, removing the surface layer on convex portions of the irregularity while leaving the surface layer on concave portions of the irregularity and making dissolution degree of the convex portions larger than dissolution degree of the concave portions.