This misconception is commonly held because the microchip manufacturers themselves chose to headquarter in California in the early 80's. The tech' industry revolution, however, started in Texas.
I got no dawg in that hunt . In fact I have no technical background in microelectronics, and my first microcomputer was a Radio Shack (Tandy) TRS-80 Model III bought in 1981. But here goes.
The scientific basis for solid state semiconductors was developed by William Shockley, who went on to invent the transistor at Bell Labs in what? New Jersey? Shockley left Bell Labs in the 50’s to open his own transistor company in Mountain View California. In nearby Palo Alto, the framework for the electronics industry complex that came to be known as “Silicon Valley” was put in place by Hewlett Packard in the late 1930’s. (I preferred their “reverse Polish” calculators to Texas Instruments’, but I may have been in the minority.)
The first integrated circuit was invented by Jack Kilby,of Texas Instruments in Jan 1959. But in Mountain View, CA, Bob Noyce (who previously worked for Shockley) was working on the IC simultaneously, and came out with his integrated circuit about 6 months later. Noyce’s IC became the industry standard.
Noyce started up Intel in the late 1960’s, where he developed the first semiconductor memory chip.
In the early 70’s one of Noyce’s engineers, Ted Hoff, came up with the microprocessor, which put all the essential functions of a computer on a single chip and it was just a small step from that to the personal computer revolution.