HELLO, EVERYONE

I WONDER WHAT IS " STOICHIMETRY AND KOH etch " ??

AND IN LPCVD I HAVE SEEN THAT THE FILM GETS AT 800C,
    TO BE DOWN THE TEMPERATURE PEOPLE ARE TRYING TMAH(tetra metal
    amminium hydroxide)

WOULD YOU INFORM ME ABOUT THE PROCESS MECHANICM SHORTLY

THANK YOU