JENOPTIK Semiconductor and Photovoltaik machines
Pulsed Laser Annealing of Power Devices and Backside Illuminated Image Sensors
Power Transistors like IGBT´s are manufactured on thinned wafers. To improve the ON resistance, wafer thickness is constantly reduced. Handling of these wafers is becoming more and more difficult. One
solution is to bond the thinned wafers to a support carrier. However, the carriers and the bonding materials are not compatible with the temperatures of annealing and activation processes.
The way out of this dilemma is the implementation of pulsed laser annealing. Due to the short pulse duration of less than 1 μs, pulsed laser annealing allows to achieve process temperatures on the exposed surface and simultaneously avoiding excess temperature levels on the bonded surface.
For other vertical power semiconductor products which have metal contacts on the front side, pulsed laser annealing reduces the number of process steps. The front side can be fully processed, including metal contacts, and the back side is annealed with pulsed laser radiation afterwards. The short pulses keep the temperature on the front side low and the metal contacts intact.
Backside illuminated image sensors are another example which benefit from pulsed laser annealing. A shallow implant layer on the surface can be activated while keeping lower lying structures like photodiodes fully intact.
Power Transistors like IGBT´s are manufactured on thinned wafers. To improve the ON resistance, wafer thickness is constantly reduced. Handling of these wafers is becoming more and more difficult. One
solution is to bond the thinned wafers to a support carrier. However, the carriers and the bonding materials are not compatible with the temperatures of annealing and activation processes.
The way out of this dilemma is the implementation of pulsed laser annealing. Due to the short pulse duration of less than 1 μs, pulsed laser annealing allows to achieve process temperatures on the exposed surface and simultaneously avoiding excess temperature levels on the bonded surface.
For other vertical power semiconductor products which have metal contacts on the front side, pulsed laser annealing reduces the number of process steps. The front side can be fully processed, including metal contacts, and the back side is annealed with pulsed laser radiation afterwards. The short pulses keep the temperature on the front side low and the metal contacts intact.
Backside illuminated image sensors are another example which benefit from pulsed laser annealing. A shallow implant layer on the surface can be activated while keeping lower lying structures like photodiodes fully intact.
The INNOVAVENT Pulsed Laser Annealers
The INNOVAVENT VOLCANO and LAVA systems both use the proprietary JenLas® ASAMA thin disk laser. It is designed for the generation of highly uniform laser lines the wafer surface is scanned with. Besides the high uniformity, the JenLas® ASAMA laser allows to program the pulse duration. By optimizing duration and energy density of the laser pulses, depth and temperature of the activation process can be precisely controlled. The result is a very high flexibility of the activation process, combined with high stability and uniformity.
Throughput depends on the process parameters and the installed laser power. More than 60 wafers/h can be realized.
For more product information, click on the link below.
Data sheet - Laser Backside Annealing
Data sheet - Laser Backside Annealing