N-600
Fingerprint Fee Was Received
Certificate of Citizenship
What this means
USCIS has the biometrics fee for your case. Next they typically schedule a fingerprint / photo appointment at an Application Support Center (ASC).
What to do next
Watch your mail and myUSCIS for an ASC appointment notice. Bring the notice and a photo ID. If you already submitted biometrics for a related case, USCIS sometimes reuses them — still keep checking for notices.