2022-09-21 10:16 Status: # Lithography Chooose where on the wafer processing is going to happen. e.g. only put gate material where you want it to be.  Then shine a light through a lens, mask and onto the wafer. Photoresist - harden without light or with light (inverts the mask).  The developed photoresist protects the area.  Light: ~320nm (hard UV) Feature size ~10nm (order of magnitude smaller than wavelength of light). Solutinons: - Immersion Lithography (use a higher refractive index liquid) - Diffraction Patterns ### Expenses and Difficulty 1. Fabricating the mask is the most expensive part - not easy to do. 2. Alignment - very accurate between process steps.  [^1] --- # References [^1]: [vr-4602-wk01-sc03-lithography](../../Spaces/University/ELEC4602%20–%20Microelectronics%20Design%20and%20Technology/Lectures/W1/vr-4602-wk01-sc03-lithography.mp4)