Spot the correct spelling of a microchip printing method.

Correct — A. Build the word from its three parts:
photo-, 'light', spelt ph
litho-, 'stone', spelt th
-graphy, 'writing or drawing', as in photography

Join them with nothing dropped: Photolithography → option (a).

Why the others are wrong

• (b)
  Photolithographe — Photolithographe ends in -e, a French-looking tail. The English suffix is -graphy, as in photography and geography.
• (c)
  Photolitography — Photolitography drops the h from litho-. The root is Greek lithos, 'stone', spelt th in English, as in lithograph and monolith.
• (d)
  Potolithography — Potolithography drops the h from photo-. The prefix meaning light is spelt ph, as in photograph and photon.

Photolithography is an optical exposure process used to make integrated circuits. Light shone through a patterned mask transfers the circuit design onto a light-sensitive coating on the chip's wafer.

The word also has a printing sense: making printing plates by a photographic process. Lithography, 'stone drawing', was named for its original stone printing surfaces.

For spelling, the parts do the work: ph, th and -graphy.

Key facts

• Photolithography is an optical exposure process used in making integrated circuits.
• Photo- means light and is spelt ph, as in photograph.
• Litho- means stone, from Greek lithos, and is spelt th.
• Lithography was named for its original stone printing surfaces.

Common traps

• Dropping one h from a long word, because ph and th each read as a single sound
• Accepting the French-looking -graphe ending

No directly related past PYQ was found.