Lithography

What is the material called, used to make photomasks, consisting of a quartz glass substrate pre-coated with a light-blocking film and similar?

  1. AMask blanks
  2. BWafer
  3. CPellet
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Answer: A. Mask blanks

Mask blanks are high-purity quartz glass substrates coated with a light-blocking film such as chromium (or, for EUV, multilayers and absorber) and resist. Patterns are written on them with an electron beam and etched to make photomasks. Japanese companies hold large shares in this field.

  • A. Correct. It is the starting material for masks.
  • B. A wafer is the silicon disk on which devices are made.
  • C. A pellet is material formed into granules.
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More Lithography questions

  1. Which correctly describes writing patterns directly into resist on the wafer with an electron beam, without a mask?
  2. How is 13.5 nm light generated in the light source of an EUV lithography tool?
  3. What is the process called that removes, with solvent, the resist that builds up around the wafer edge after spin coating?
  4. In current scanner exposure tools, what is the typical maximum area on the wafer that can be exposed in one exposure (one shot)?
  5. Which technique uses computation to jointly optimize the illumination shape of the exposure tool and the mask pattern to improve resolution?