I don't see this as an actual sleep disturbance necessarily, but it is a forced deliberate disturbance of your sleep.

You wrote "The thing is I won't actually wake up, but I'll sleep lightly as I'm hitting snooze for hours."

The above sounds like you could sleep if you let yourself, but the action of setting the alarm to wake yourself up seems like you want to be awake for some reason, even if waking up early wouldn't be what you'd naturally do.

Are you really getting manic? Or are you wishing you were manic and wishing you could somehow make yourself manic by disrupting your sleep? If the answer to the latter question is "yes", beware that disrupting your sleep deliberately can have the opposite effect than perhaps what one wants. Sleeping less does in fact sometimes cause depression despite the view that it only causes mania. Again, if the latter is "yes", talk to your doctor or try to self analyze why you really are playing with your sleep so much.

My suggestion would be to set your alarm for 7:45 am and see if you can get a longer night's sleep. Don't set your alarm for 3 am unless you have a 5:30 am flight somewhere. If you allow yourself a normal night's sleep but wake up without an alarm after only a few hours sleep, then I'd think you have a sleep disturbance, which may or may not be related to mania.