The quote that you have about the 1997 patent, namely "U.S. Pat. No. 5,659,925 teaches a process for adjusting the deposition rate..." is from the specification. That is written by either the inventors or more likely the attorneys filing the application. The specification is not legally enforceable or binding. It is supposed to disclose enough information to let somebody reproduce the claimed invention. As a matter of practice, the specification can say almost anything it wants, including non-enforceable things.
Only the claims are legally enforceable. I suggest taking a closer look at the claims and seeing if these are problematic for your application or not. You may want to consult an attorney if you have further questions.
You can look up the patent examiner's reasoning for allowing the application here:
https://patentcenter.uspto.gov/applications/17667081
Click on "Documents and Transactions" and look for "Notice of Allowance and Fees Due". Also look for the "Non-Final Rejection" for additional information from the examiner from an earlier version of the application.
I should note that it does not appear that the patent examiner considered the 1997 patent directly relevant because they did not cite it in any of the office actions or specifically the PTO-892 forms (search the documents page for 892 to see what I'm talking about). However, they likely did at least look at it since it is listed in the specification.
Again, if you have further questions, you really should consult an attorney. This is not a good forum for this kind of discussion, in my opinion.