I was a Masters student when I was interviewed, so they asked me basic questions like cross section of an NMOS, its V-I characteristics, a couple of logical questions on this like how the curves shift if a resistor is added at its drain, etc, a couple of questions on DRAM, its leakage paths, clocking, etc, CMOS logic, temperature effects on the mobility of charge carriers in an NMOS, etc and some basic C programming questions about pointers, etc. Some questions were quite tricky like "Write a C program which performs multiplication operation without using the multiplication operator", etc.
The interview started at 10 AM in the morning and ended at 4 PM in the evening. I had six interview sessions and each session had two interviewers, one the manager of the respective test division (e.g., burn-in) and a head engineer from that division. After the first interview, I was fortunate enough to be invited for lunch with one of the senior test engineers there, we talked about a lot of things ranging from my technical interests to Micron's past to the city of Boise. He also took me on a tour of their testing and fabrication facilities. It felt truly enticing to know that the memory chips that sit in our computers come from here! The final interview session consisted of the DRAM and the Probe and Test Managers. This was mentally slightly stressful in comparison to the others and most of it was C-programming. In the end, at around 4 PM, my recruiter escorted me out from the manager's cabin to the front desk and let me off.