Anyone can become a multimillionaire, but they never do it by working a job. Income leads to investments, investments lead to passive income and wealth growth, and wealth growth is what you're looking for.
It's currently a good field of law to go into, that's for sure, but there are some risks. IP Law is starting to get legislated to hell the way bankruptcy and personal injury were, thanks to the patent trolls. You need to get a useful undergrad degree in a science or discipline of engineering. This would include computer science, insofar as it covers programming. You can get paid well if you go to a top-tier law school, graduate in the top of your class, were on law review, and were published at some point. But even then, you won't earn enough to be a millionaire, let alone a multi-millionaire unless you learn how to build and/or invest in passive income producing businesses.
Wealthy lawyers are *gasp* a Hollywood myth. Most of them live paycheck to paycheck thanks to stupid money decisions.