I was contacted the day after I applied by email to request a phone interview later that week. The phone interview question were about half technical and half experiential, such as, "Describe a time when..." Two days passed before I was called in for a panel of interviews, lasting from 9 am to 3 pm. The first interviewer was from HR, and the other 6 were engineers. Most of the technical questions were basic. Three of them asked me to draw a cross-sectional diagram of a MOSFET of various types.
One interviewer asked very detailed questions regarding device physics and system characterization. I recommend studying up on different memory device operations, knowledge gained from C-V plots after burn-in, and how different problems with oxides may be detected.