On 1,100 acres in the Arizona desert north of Phoenix, a newly completed 3.5-million-square foot building is making history as the most advanced chip fabrication plant on U.S. soil. It's Taiwan Semiconductor Manufacturing Company's first of three Arizona fabs, which will total a $65 billion investment when they're complete at the end of the decade. Apple has committed to being the site's largest customer. Full production has been delayed until 2025, but pilot production has begun. CNBC got an exclusive first look at the fab, where TSMC chairman Rick Cassidy says the project is "dang near back on the original schedule."