Background
I changed jobs a little over one and a half years ago because I wanted a more technical role (I'm a junior SW developer now, before I was a developer using a low-code platform). I even took a few percent cut out of my total compensation to make the switch and I enjoy my current job more.
Our company gives raises every half year - December and May. I didn't get a raise during first wave of raises (May 2018) because of my performance, which I managed to fix and my managers have been satisfied with me for over a year now. Unfortunately, the company got into financial issues and didn't give any raises last December and only gave raises to a few exceptions this May. I was one of the exceptions, but I believe I'm still earning below market rate. My boss wanted to give me double the raise I received, but our big boss denied his initial suggestion. I told my boss that I expected a bigger raise and he said I still can talk to our big boss, which I'm not comfortable with. It's also not clear when will company's financial situations improve, so I might see a limited or no raise again in December. I'm also afraid I'm less likely to be promoted in this environment.
Actual problem/question
So I've been seriously thinking about switching jobs with money being the primary motivator. My problem is that I'm not sure how to approach this correctly. Should I talk to my boss and make it very clear that I'm not satisfied? Is it a good idea to mention this when interviewing or should I completely focus on other reasons why I'd like to make the change?