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
A mechanical hit occurs
Redesign the pedestal or add a ring having no "walls" - no parts that the wafer can hit
Wafer moves due to air pressure difference appearing due to flash heating
Keep the wafer static - no movements at all (vacuum keeper?)
The pedestal has a special configuration: the wafer moves and can get a mechanical hit
Redesign the pedestal to exclude a mechanical hit
How wafer breakage occurs while the flash heating process:
Pedestal | 10 |
Low lamp | 7.5 |
Bumps | 5 |
Upper light (flash) | 5 |
Centering pins | 5 5 |
Atmosphere (N2) | 10 |
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 |
Similar projects
Wet cleaning is widely used in microchip manufacturing. Single wafer equipment is working as follows. A wafer rotates, and chemistry is poured from a movable nozzle. Water rinsing is performed at the end of the process. Loading of a new batch of the chemistry resulted in excursion - a strongly increased amount of defects was observed on the wafer after the processing. The project is dedicated to the failure analysis and creation of innovative solutions.
