Plasma Dicing Semiconductor Wafer Tape Frame
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Solution Overview
Problem
Current plasma etching equipment is not compatible with substrates mounted on tape and supported in a frame for dicing, limiting the adoption of plasma dicing techniques for semiconductor substrates, which require additional complex steps and are not compatible with standard downstream processing equipment.
Innovation Solution
A method involving a substrate masked on the front side with conventional techniques, mounted on a thin tape supported within a rigid frame, and processed in a vacuum chamber with a high-density plasma source, where the frame and tape are protected from damage, allowing for complete separation of die and subsequent residue removal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If plasma etching equipment is used for substrate processing, then high etch rates and cost-effective manufacturing are achieved, but the equipment is not compatible with substrates mounted on tape and frame for dicing
Solution Approach 1:
The substrate processing is segmented into two distinct phases: (1) mounting the substrate on tape within a frame using conventional dicing equipment, and (2) transferring the mounted substrate to plasma etching equipment for dicing. This segmentation allows each process to be optimized independently, resolving the compatibility issue between plasma equipment and tape-mounted substrates while maintaining high etch rates
Solution Approach 2:
The tape and frame serve as an intermediary structure that enables the substrate to be handled in a manner compatible with both conventional mounting techniques and plasma etching processes. The tape provides a flexible support that accommodates the substrate during plasma processing, while the frame provides structural stability, acting as a mediator between the substrate and the plasma etching equipment
2Ease of manufacture
If mechanical dicing methods are used, then substrate separation is achieved, but chipping and breakage occur along die edges and kerf area is lost
Solution Approach 1:
The patent replaces mechanical dicing methods (sawing, breaking) with plasma etching to separate the die. The plasma process uses reactive ions to remove material chemically rather than mechanically, eliminating the chipping and breakage associated with mechanical contact while achieving precise die separation with minimal kerf loss
Solution Approach 2:
The patent changes the fundamental parameter of the dicing process from mechanical force to plasma chemistry. By controlling plasma parameters such as gas composition, power, and pressure, the process achieves clean die separation without the physical contact that causes edge damage in mechanical methods
3Ease of manufacture
If mechanical dicing is used for wafers with many small die, then separation is achieved, but dicing time is increased and productivity is decreased
Solution Approach 1:
The plasma etching process enables continuous dicing of all die across the wafer surface simultaneously, rather than sequentially processing each street as in mechanical methods. The plasma field uniformly acts on all exposed substrate areas, allowing parallel processing of multiple die separations and significantly reducing total dicing time
4Ease of manufacture
If mechanical dicing is used, then straight line separation is achieved, but non-rectilinear die formats result in significant loss of useable substrate area
Solution Approach 1:
The plasma etching process provides dynamic flexibility in defining die separation patterns, allowing curved and non-rectilinear streets to be etched with the same precision as straight lines. This dynamic capability enables the dicing pattern to match the actual device topology, maximizing the useable substrate area for non-rectilinear die formats
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
Enables efficient plasma dicing compatible with established handling techniques and standard equipment, reducing breakage, kerf dimensions, and processing time, while allowing for non-rectilinear die formats and improved productivity.
Implementation Method 1
A plasma source is provided which generates a plasma used to etch the substrate
Implementation Method 2
Fluorine containing gases, such as SF6, F2 or NF3 are used to etch silicon at a high rate
Implementation Method 3
A cooling gas (typically Helium) is maintained between the substrate and the support to provide a thermal conductance path for heat removal
Implementation Method 4
An Electrostatic chuck (ESC) is used to provide the clamping force
Data Source
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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 a work piece onto the work piece support, said work piece having a support film, a frame and the substrate; loading the work piece onto the work piece support; applying a tensional force to the support film; clamping the work piece to the work piece support; generating a plasma using the plasma source; and etching the work piece using the generated plasma.