Substrate Pretreatment for Back Surface Hydrophilic Polishing
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Solution Overview
Problem
Current substrate treatment apparatuses face challenges in effectively reducing the amount of adhered substances on the back surface of semiconductor wafers during the polishing process, as the back surface cleaning is difficult due to working against gravity, leading to potential issues like focal position shifts in lithography processes.
Innovation Solution
A substrate treatment apparatus that includes a pretreatment unit for performing a hydrophilic process on the pre-polishing back surface of the substrate, followed by a polishing unit that polishes the front surface with the back surface having undergone hydrophilic treatment, enhancing the removal of slurry residues and improving cleaning efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If polishing is performed on the front surface of the substrate, then the front surface is planarized, but adhered substances accumulate on the back surface
Solution Approach 1:
The patent applies preliminary hydrophilic treatment to the back surface of the substrate before polishing. This preliminary action modifies the surface properties of the back surface to reduce adhesion of polishing solution and adhered substances, preventing the accumulation problem that would otherwise occur during front surface polishing
Solution Approach 2:
The patent changes the surface parameter of the back surface by applying hydrophilic treatment, which alters the wettability and surface energy characteristics. This parameter change reduces the adhesion force between the back surface and polishing solution residues, thereby reducing adhered substances during the polishing process
2Object-generated harmful factors
If back surface cleaning is performed, then adhered substances are removed, but cleaning is difficult due to working against gravity
Solution Approach 1:
The hydrophilic treatment is applied as a preliminary action before polishing, preparing the back surface to minimize adhered substance accumulation. This reduces the cleaning burden that would otherwise be difficult due to gravitational effects
Solution Approach 2:
The hydrophilic treatment creates a preliminary anti-adhesion effect on the back surface, counteracting the tendency of polishing solution to adhere to the back surface during polishing. This preliminary anti-action reduces the amount of cleaning required against gravity
3Object-generated harmful factors
If hydrophilic treatment is applied to the back surface, then wettability is improved and adhered substances are reduced, but an additional process step is required
Solution Approach 1:
The substrate treatment apparatus is designed to perform both hydrophilic treatment of the back surface and polishing of the front surface within a single integrated system. This multi-functionality approach adds the necessary process step while maintaining operational efficiency and reducing the need for separate equipment
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
The hydrophilic treatment on the back surface reduces the amount of adhered substances, improves wettability, and facilitates easier removal of slurry residues during cleaning, thereby enhancing the cleanliness and reducing defects on the wafer surface.
Implementation Method 1
a pretreatment unit that performs a hydrophilic process on a pre-polishing back surface of a substrate
Data Source
AI summary
A substrate treatment apparatus includes: a pretreatment unit that performs a hydrophilic process on a pre-polishing back surface of a substrate; and a polishing unit that polishes a front surface of the substrate having the back surface subjected to the hydrophilic process performed by the pretreatment unit.