Intel Corporation Process Engineer interview questions

Applied for Process Engineer position at Intel (Wafer processing area) and got an email from Manager/Supervisor to schedule an interview time. Phone interview was an hour long, and very in depth. He asked very in depth questions about my research and work. For example: I mentioned I worked with synthesis and my background was in Chemistry, he proceeded to ask me what "pH" stood for and to define it to fully judge my knowledge. Asked for me to describe in detail the components of analytical instruments like XRD, SEM, TEM, even though that's nothing like what the position was for at all. He was very knowledge and though I didn't give perfect answers, I tried. At the end I was offered an on-site interview.

Got an email to schedule a 1 h phone interview. After passed this process, I was invited to an onsite interview. It was scheduled from 8 am to 5 pm including a research presentation and 7 one-to-one interviews without any rest time. Some tough question to my research projects since interviewers had various backgrounds from physics, engineering, etc.