Why turkey has the same name as Turkey
A region on the San Francisco Peninsula in California where the miniaturized electronics industry is centered, so called because most of the devices built there are made of semiconductors such as silicon.
Note: The term is often used as a catchword to describe the development of high-tech industry: “If we can attract this corporation to our town, we could become another Silicon Valley.”
The Santa Clara Valley south of San Francisco in California: smack in the middle of Silicon Valley
[1974+; fr the concentration of manufacturers of silicon chips for computers, watches, etc, in the Santa Clara Valley]