Due to some previous save errors, i turned on phped backups which creates all of these *.php~ files

although i have the file mask set to *.php, when i search in all files, the search returns results in the backup files

is there a way to ignore these?

Yes, add the *.php~ extension to the list in file associations for "Picture" filetype -- misleading but extensions and wildcards listed there will be ignored by search.