SILICON

Nonmetallic element used in integrated circuits (in a California valley?) (7)

Solution has appeared in 2 crosswords (2 across and 0 down):

• Quick crossword No 16,515 — 2023-04-11 23:00:04
  23A: Nonmetallic element used as a semiconductor in transistors (7)
• Quick crossword No 15,957 — 2021-06-28 23:00:00
  21A: Nonmetallic element used in integrated circuits (in a California valley?) (7)