The thing that works for me is waking up (with an alarm) every day at the same time (6 o'clock) including week-ends.
I have a "dawn simulator" clock so most of the time I'm already awake when the alarm rings. But no matter what, when it rings I get out of bed immediately. You snooze you loose!
If you know you have to be up by X then be sure to go to bed at X-Y. I would imagine the struggle is winding down for bed early rather than waiting till you "feel tired" to go to sleep. Artificial light and stimulation makes it easy to stay up way later than intended.
Once you're tired from waking early, you're far less likely to look at your phone too late.
However - then I started a job where I had to travel between time zones, and I still haven't figured out how to get the body to know that it's traveled quickly other than mealtime & nap manipulation the day before, and even then I still need alarms.
That’s what it felt like, like I had very limited time to shove x amount of things into my brain which only processes at y rate, so if I had too many things to shove in at a time due to taking a full courseload, that meant staying up since I cant change the rate my brain digests information without abusing stimulants like some of my friends.
So then you end up with a few nights of 5 hour sleep which you pay for by sleeping for 13 hours on the weekend. Not healthy, but it became a matter of necessity due to also having to make time for a part time job.
When I had an important exam or something else I really didn't want to miss, I'd set an alarm for a while. But then I just went all in, and never set an alarm. That made me pay more attention to when I was going to bed at night, and the quality of my sleep. When I started working I would set an alarm for about half an hour after I typically woke up, just in case, so I wouldn't be late for work. But after six months of that, I stopped setting my backup alarm as well. I was late for work maybe twice in five years, and it was never significantly late, and it was at times where my body really needed sleep and it probably helped me avoid getting sick. These days I only set an alarm if I have to catch a 6am flight, or if I'm getting up super early to climb a mountain or something.
If you're battling your alarm every day, I highly encourage you to experiment with not setting an alarm.