As strange as it may sound, you may actually practice getting up on the sound of alarm clock. This is a known (not famous though) pshycological technique.
Mamals works on reflexes. Google conditioned reflex by Ivan Pavlov for technical details (not on waking up but on reflexes and actions).
In the evening, when you're not stressed. Just set the alarm after 5 minutes past current time. Go to bed, and pretend to sleep. Yes! You are trying to fool your mind. When it rings simply get out of the bed, and go wash your face. Do this 3-4 times daily for 5-7 days, I bet you'll see the difference.
Disclaimer: I am not claiming to have invented this technique, just sharing what I have learned. Hope this helps.