Elastic Coating Layer on Suction Protrusions for Wafer Planarity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional suction apparatuses for holding materials like wafers suffer from foreign material interference, leading to deformation and excessive polishing, which results in defects during planarization, and existing solutions either fail to completely eliminate these issues or introduce new problems like undulations and manufacturing difficulties.
Innovation Solution
A suction apparatus with a rigid substrate and an elastic coating layer on the suction surface, where the coating layer is configured with a polyurethane, acrylic, or fluorine-based resin, and an undercoat layer to reduce foreign material effects and enhance planarization, while preventing localized excessive polishing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a rigid suction substrate with pin-like protrusions is used to hold the wafer, then the wafer can be held planarly against the protrusions, but foreign materials can become interposed between the wafer and suction surface causing deformation and excessive polishing
Solution Approach 1:
The patent applies this principle by coating the rigid suction substrate with an elastic coating layer that has flexibility. This elastic layer acts as a buffer between the rigid protrusions and the wafer, allowing it to deform and accommodate foreign materials without transmitting deformation forces to the wafer, thereby preventing bulge formation while maintaining planar holding capability
Solution Approach 2:
The patent combines rigid and elastic materials to create a composite suction substrate structure. The rigid substrate provides structural support and planarity, while the elastic coating layer provides flexibility to absorb foreign material interference. This composite structure resolves the contradiction by integrating both hardness for planar holding and elasticity for foreign material tolerance
2Object-affected harmful factors
If the contact surface area between wafer and suction surface is reduced to tip-end faces of protrusions, then foreign material interposition is reduced, but the suction holding reliability decreases
Solution Approach 1:
The elastic coating layer on the protrusions maintains the reduced contact area configuration while adding flexibility. This allows the system to benefit from reduced foreign material interposition probability while the elastic material compensates for the reduced contact area by providing conformal contact and distributed pressure, thereby maintaining suction holding reliability
3Object-affected harmful factors
If an elastic layer is affixed to the tip-end faces of protrusions using double-side adhesive tape, then foreign material effects are reduced, but the thickness increases causing undulations in the wafer
Solution Approach 1:
The patent uses a thin elastic coating layer instead of a thick affixed elastic layer. This coating layer provides the necessary flexibility to reduce foreign material effects while maintaining a thin profile that does not cause undulations in the wafer during polishing, thereby resolving the contradiction between foreign material protection and manufacturing precision
Solution Approach 2:
The coating layer is integrated as part of the suction substrate composite structure rather than being a separate affixed layer. This integration ensures proper adhesion and thickness control, preventing the delamination and thickness-related undulation problems associated with double-side adhesive tape applications
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 solution effectively reduces the impact of foreign materials, improves planarization, and prevents excessive polishing, leading to better semiconductor device manufacturing yields and lower costs by maintaining a stable and uniform surface during the suction process.
Implementation Method 1
at least one elastic coating layer coated on said suction substrate on said side to which said material to be suctioned is suctioned
Implementation Method 2
a negative pressure is created in depressions between the protrusions in a state in which the tip-end faces of the protrusions are in contact with a wafer to ensure the wafer is held planarly
Data Source
AI summary
A suction apparatus 1 holds a wafer W by performing vacuum-suctioning on the wafer W. The suction apparatus 1 comprises a suction substrate 2. The suction substrate 2, which is rigid, comprises a plurality of pin-like protrusions 2a formed so that the tip-end faces (upper surfaces) thereof are the same height. An elastic coating layer is coated by way of an undercoat layer 4 on the tip-end faces of the protrusions 2a. When the wafer W is suctioned, even if a foreign matter is interposed between the wafer W and the suction surface, because the foreign matter embeds itself into the coating layer 3, the planarization of the wafer W is improved. In addition, because the coating layer 3 can be made comparatively thinner, undulations in the wafer W can be reduced and, to that end, the planarization of the wafer W in the suctioned state can be improved.