Hello,
Verbs that show movement, change in state, and sein, werden, and bleiben take "sein" when in perfect form and the rest of the verbs take "haben". Since "aufstehen" which means "to get up", it indicates a change of state and therefore we need to use "ist" (form of sein).
As suggested in some of the other questions on the forum as well, it does not help to try to use the rules of English language when you are writing in German because both are distinct languages with their own sets of grammatical rules and usages.
Hope this helps.