1. Fabrication of a Photodetector Array on Thin Silicon Wafer
Kim Manser (RIT, MicroE Co-Op)
Background
RIDL is currently designing and fabricating a focal plane array that could be used on future NASA astrophysics and planetary space missions.
This detector does stuff that’s different than current detectors
Device Fabrication Flow Chart
Goals
Kim is working on something towards the overall goal of making the detector
Plan
Kim will do certain tasks to work towards completing the goal stated above …
Device Operation
The device is made up of a detector (collects light and generates a current) and the ROIC (to translate the detector’s signals into image information).
When a photon is incident on the detector, it excites an electron-hole pair, which are then freed from the silicon crystal lattice and carried to opposite sides of the device (where the current is collected in localized areas called pixels).
The detector ouput circuit converts the integrated charge into a voltage that represents a signal that is proportional to light.
Above is a flow chart of how this device will be fabricated
The readout integrated circuit (ROIC) has been designed by a team headed by Dr. Zeljko Ignjatovic at the University of Rochester and is being fabricated by an outside facility.
The detector design is currently under fabrication at RIT in the Semiconductor and Microsystems Fabrication Laboratory, a class-100 clean room.
Photodetector
ROIC
n-Si
Thermal oxide
n+ Si
p+ Si Al
LTO In
Bonds to ROIC
Section describing Kim’s work in the fabrication process
Kim is working on the photodetector fabrication….
She is modeling the fabrication process…
Cross-Sectional View
photons