At Lam Research Corporation we want to hire those with at least a basic understanding of semiconductors. Why are some semiconductors made of silicon?

The interviewer is testing your basic industry knowledge. The better you understand a topic, the more clearly you should be able to answer a question like this. Keep your answer concise. 'I don't know' is never an acceptable answer. You should be transparent with the interviewer that you are unsure of the solution but offer any piece of knowledge that you may have.

If you know the answer: "From my understanding, some semiconductors are made of silicon because the semiconductor can then be used at much higher temperatures; for electronics, for example."