If you're having a hard time waking up on time in the morning, you might need to adjust your schedule to align with your sleep cycles. The closer you can line up with the 90-minute rule, the better.
As the video above from video essay channel Ismonoff explains, your brain goes through roughly 90-minute cycles of sleep every night. The process begins once you start sleeping -- not once you lay down in bed to read your phone -- and repeats every hour and a half or so. If you wake up in the middle of that cycle, you're going to have a harder time waking up and you'll feel less rested throughout the day.
On top of this, your brain needs sleep to be a "time off" period. That's why screen reading at night is so bad. If you put your brain to work right before it rests, you're still stressing it a bit. Instead, turn off the gadgets and let your brain take a break. The sooner you get in bed and rest, the easier it will be to wake up in the morning.
How To Wake Up Early Everyday [Ismonoff]