Plasma Dicing Semiconductor Wafer Tape Frame Assembly
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current plasma etching technologies for dicing semiconductor wafers are not compatible with standard wafer handling techniques, particularly those using substrates mounted on tape and supported in a frame, limiting the adoption of plasma dicing methods that could reduce breakage and increase productivity.
Innovation Solution
A plasma processing apparatus that mounts the substrate on a thin tape supported within a rigid frame, allowing the substrate/tape/frame assembly to be processed in a vacuum chamber with a reactive gas plasma to separate the die without damaging the frame or tape, and subsequent removal of residues, enabling compatibility with established dicing techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If plasma etching is used to dice semiconductor wafers, then breakage is reduced and productivity is increased, but compatibility with standard wafer handling techniques is lost
Solution Approach 1:
The apparatus segments the wafer processing by separating the plasma etching chamber from the wafer handling system. The wafer is mounted on a carrier with a frame structure that can be selectively positioned, allowing the wafer to be exposed to plasma only in the etching chamber while remaining protected during handling. This segmentation enables plasma dicing to be integrated into existing handling workflows without requiring complete system replacement.
Solution Approach 2:
A frame structure acts as an intermediary between the wafer and the plasma environment. The frame provides mechanical support and protection during handling while being transparent or accessible to plasma during etching. This intermediary component allows the wafer to be processed by plasma etching while maintaining compatibility with standard carrier-based handling techniques used in semiconductor manufacturing.
2Strength
If mechanical clamping is used to secure the substrate, then the substrate is held firmly, but contamination occurs due to contact between clamp and substrate
Solution Approach 1:
The patent replaces direct mechanical contact clamping with an electrostatic chuck system that uses electrostatic forces to hold the substrate. The electrostatic chuck creates a strong holding force through electrical attraction between the chuck surface and the substrate, eliminating the need for mechanical clamps that would physically contact and potentially contaminate the wafer surface. This substitution maintains strong securing while preventing contamination.
3Object-generated harmful factors
If electrostatic chuck is used to provide clamping force, then contamination is avoided, but work piece bowing occurs due to pressurized fluid force
Solution Approach 1:
The apparatus applies local quality by creating zoned pressure distribution through the frame structure. The frame provides localized mechanical support at specific points while the electrostatic chuck provides distributed holding force across the wafer surface. This combination allows the wafer to be held firmly without excessive uniform pressure that would cause bowing, as the frame structure compensates for local pressure variations and maintains overall flatness.
4Strength
If thick wafers are processed, then mechanical strength is maintained, but processing time increases
Solution Approach 1:
The plasma etching process enables parameter changes in wafer thickness processing. Unlike mechanical dicing that requires serial cutting through the entire thickness, plasma etching can selectively remove material at controlled rates. The process parameters (power, gas flow, pressure) can be adjusted to optimize etch rate for different thicknesses, allowing thin wafers to be processed quickly while maintaining adequate etch control for thicker wafers, thereby reducing overall processing time across all thickness ranges.
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 reduces breakage and kerf dimensions, increases productivity by reducing processing time for thinner wafers, and allows for non-rectilinear die formats, while maintaining compatibility with standard dicing equipment.
Implementation Method 1
plasma etching to separate the wafer into individual die
Implementation Method 2
an electrostatic chuck (ESC) is used to provide the clamping force
Implementation Method 3
A pressurized fluid, typically a gas such as Helium is maintained between the substrate and the support to provide a thermal conductance path for heat transfer
Data Source
AI summary
The present invention provides a method for plasma dicing a substrate. The method comprising: providing a process chamber having a wall; providing a plasma source adjacent to the wall of the process chamber; providing a work piece support within the process chamber; placing the substrate on a carrier support to form a work piece; providing an intermediate ring interposed between the substrate and the frame; loading the work piece onto the work piece support; generating a plasma through the plasma source; and etching the work piece through the generated plasma.