It sounds like you are feeling exploited as well. Have you sought out getting a raise that's, at least, on par to these hires? Since they've kept you around, I imagine you're a very valuable employee. Is getting another job as a senior semiconductor engineer easily done? Money is certainly not everything. I still have mixed feelings about leaving my current employer. Other than the salary, I really like working there so if that's why you're staying, I totally understand. Besides the salary, another motivator for me is that my wife is expecting with our first. Subconsciously, I think this has driven me more to seek out to be a better provider. I guess it's called "provider panic".
Yeah - so I've tried to get a raise, and no go. We are a startup, and we are always low on cash. So it's a hard sell, and I hear "well, you have STOCK!" Uh huh, and I'm fully vested, I can exercise and leave.
I live in a small town, with not a lot of options. I have dipped my toe into the job hunt, and had a couple of interviews. One place was super scary. The other place was awesome, but they ended up not filling the position that I interviewed for.
My problem is, somewhat, that I am picky.
1. I can't move. My husband makes more money, his job is primary.
2. I'm not willing to increase my work hours to a ridiculous amount. I work about 40 now. I have two kids, almost 9 and 2.5, and well, working FT with them sucks - I'm not going to make it worse.
3. I want the job to be interesting.
So, I go along with the idea that if it feels right, I'll send my resume and interview. For the job that I really wanted, though, I took 3 days off work - one to prep for a presentation (while my husband was out of town), one to practice it, and a full 8 hour interview day. With two kids, I don't have a lot of spare PTO so using that and not getting the job really hurt.
It really sucks about not being many women in engineering. There were several senior female engineers, then we got a new (awful) VP boss, and man, I'd never ever felt the glass ceiling so hard. Even the guy who got the (my) promotion to engineering manager said "your problem was being born a woman". (Really, my problem was the new boss, the old boss was going to promote me and when he transferred, he recommended me for the position.)
BUT, those things are out of my control and fighting for them and stewing about it will do me no good, so I transferred to a new position where I am learning new things and I'm pretty independent. And I work my 40 and go home to my family.