The full cycle is about two years, and the longest manufacturing is three months.
How long the production of chips depends on what type of chip you want to do, if you do a new AI chip, from design to mass production takes at least two years, of which chip design and verification needs at least one year, the flow, testing, mass production is basically close to a year, two years for the chip is actually a very normal cycle. Even iterating on a chip can take a year to upgrade. For chip manufacturing, a little longer than three months, the low-end process may be a few days.
First to design the chip, and then find a foundry to process the chip, generally takes 2 to 3 years.