You can use 'grep' with the option '-rwl' (force case distinctions) or '-rwli' (ignore case distinctions)
grep -rwl "your_keyword" folder_to_search
OR
grep -rwli "your_keyword" folder_to_search
The meaning of those options are as follows:
-l, --files-with-matches print only names of FILEs containing matches-r, --recursive like --directories=recurse-w, --word-regexp force PATTERN to match only whole words-i, --ignore-case ignore case distinctions