Wafer breakage at flash heating
Wafer breakage within the flash heating system:
The flash heating with the upper lamp created the gradient of the temperature of the air. The fast-changing of temperature results in the wind (tornado) formation that leads to the movement of the wafer. The moving of the wafer may result in a mechanical hit followed by the wafer breakage.
Wafer breakage occurs at flash heating
Run additional wafers to compensate for the broken wafers
0
A mechanical hit occurs
Redesign the pedestal or add a ring having no "walls" - no parts that the wafer can hit
3
Wafer moves due to air pressure difference appearing due to flash heating
Keep the wafer static - no movements at all (vacuum keeper?)
1
The pedestal has a special configuration: the wafer moves and can get a mechanical hit
Redesign the pedestal to exclude a mechanical hit
2
How wafer breakage occurs while the flash heating process:
Operational Effectiveness – OE
Effective
Ineffective
OE 2.17
Operational Perfectness - OP
Basic functions
Components
Supersystems
OP 0.62
Pedestal | 10 |
Low lamp | 7.5 |
Bumps | 5 |
Centering pins | 5 10 |
Upper light (flash) | 5 |
Atmosphere (N2) | 5 |
The main conclusion is that we need to exclude either movement of the wafer or vertical solid parts that the wafer can hit
If | we exclude the wafer movement |
|---|---|
Then | no breakage will occur due to a mechanical hit |
But | The thermal stress could appear and affect the parameters of the product or even result in breakage due to thermal stress |
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