Been there, done that, bought the tshirt. Our unwakeable highschooler is now 22 and let me just say, he’s amazing. Here’s what we did. In 9th & 10th, we woke him up everyday. Then in 11th grade we started to have concerns about the future just like you’re having. We tried the sonic boom clock but it only woke everyone else up and not him. He was responsible for taking his brother & a neighbor to school so I continued to wake him up because I didn’t think his brother & the neighbor should have to suffer the consequence of being late. However,on occasion throughout 11th grade, he diddn’t have to take anyone to school so we used these days as a trial run for him being responsible to get himself up. We told him well In advance that he needed to get himself up. We set him up for success by helping him get ready the night before and going to bed at a decent time. We set several alarms. At least three. And two of them required that he get up to turn them off. We also discovered that the fan he had on in his room was just loud enough to keep him from hearing any of his alarms so we tried turning it off on the nights he was getting himself up in the morning. He knew ahead of time that if he did not get up we would not wake him up and that he would have to suffer the consequences of being late to school. Sometimes he got up and totally surprised us but other times he was late. It was hard to let go and allow the consequences to happen but by the time senior year rolled around he had enough practice and enough consequences that we knew it was time to make him responsible to get up every day on his own. Some days he did really well and others he did not but once he suffered the consequences at school on several occasions he began to wake himself up on his own, on time. It wasn’t pretty and he was often in a rush but he did get up on his own. Even now going to college he still wakes up late sometimes but instead of getting mad at us he gets mad at himself and realizes that it’s time to switch the sound on his alarm. He can’t leave it on the same sound more than 2 or 3 days in a row because his brain will get used to it and not wake him up anymore. I don’t know what will work for your son but that’s what we did and he now gets himself up and figures out what works and what doesn’t on his own. Good luck and just keep trying different things until he gets better and wakes up on his own.