This could be so many different things it's going to be hard to give you an answer. First of all, you haven't stated what you're doing. Is this a SELECT query and your drive is filling up? Then we need to look, probably, at what the query is doing and how much it's using tempdb to satisfy the code. Hash joins or hash aggregates can use quite a lot of tempdb. Sort operations. Other aggregates. Calculations. It's really hard to say without a lot of detail.
Are you moving data around, INSERT/UPDATE/DELETE. Well, how much. Is it doing sorts, etc.?
Server settings, to a lesser degree, can affect this, as can database settings.
However, with no knowledge of what's happening, I can't tell you what's happening.