Photo Lithography
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Transcript of Photo Lithography
![Page 1: Photo Lithography](https://reader031.fdocuments.net/reader031/viewer/2022032123/563dba48550346aa9aa43ec3/html5/thumbnails/1.jpg)
Photolithography
![Page 2: Photo Lithography](https://reader031.fdocuments.net/reader031/viewer/2022032123/563dba48550346aa9aa43ec3/html5/thumbnails/2.jpg)
Purpose
The purpose of photolithographyis to deposit a layer of photoresist
on a wafer
This layer is then developed and the pattern is transferred
onto the wafer
![Page 3: Photo Lithography](https://reader031.fdocuments.net/reader031/viewer/2022032123/563dba48550346aa9aa43ec3/html5/thumbnails/3.jpg)
Rinse and spin dry
Wafer Cleaning
Before applying photoresist, it is important to remove dust, dirt, and other contaminants from
the wafers
![Page 4: Photo Lithography](https://reader031.fdocuments.net/reader031/viewer/2022032123/563dba48550346aa9aa43ec3/html5/thumbnails/4.jpg)
Bake after applying photoresist
Apply Photoresist
Apply photoresist evenly in a circular motion
![Page 5: Photo Lithography](https://reader031.fdocuments.net/reader031/viewer/2022032123/563dba48550346aa9aa43ec3/html5/thumbnails/5.jpg)
Mask Alignment and Exposure
Masks are used to produce patterns on wafers
![Page 6: Photo Lithography](https://reader031.fdocuments.net/reader031/viewer/2022032123/563dba48550346aa9aa43ec3/html5/thumbnails/6.jpg)
GLASSCr
Masks are made of glass and chromium
WAFERMETALPHOTORESIST
Shining UV light through the mask exposes some of the photoresist
PR
The photoresist that has been exposed can then be easily removed, leaving the unexposed photoresist on the wafer
![Page 7: Photo Lithography](https://reader031.fdocuments.net/reader031/viewer/2022032123/563dba48550346aa9aa43ec3/html5/thumbnails/7.jpg)
Once aligned, expose to UV lightBefore exposing, align mask and wafer
![Page 8: Photo Lithography](https://reader031.fdocuments.net/reader031/viewer/2022032123/563dba48550346aa9aa43ec3/html5/thumbnails/8.jpg)
Develop
Place wafer in developer to remove photoresist that has been exposed to UV light
After developing, hard-bake the wafer, and then you are ready to etch!