The　problem　of　etching　holes　was　researched　during　the　fabrication　of　boron-doped　p+-silicon　free-handing　diaphragm　using　anisotropic　wet　etching　techniques.　Many　MEMS　structures　need　twice　deep　etching　or　even　more,　and　usually　the　free-handing　diaphragm　is　achieved　after　several　deep　etching,　In　this　case,　it　is　likely　that　some　micro-etching　holes　can　be　found　on　the　surface　of　the　film.　Researches　show　that　the　formation　of　the　etching　holes　does　not　begin　in　the　second　deep　etching,　but　begin　with　the　destroy　of　the　mask　in　the　first　deep　etching.　The　destroy　of　the　mask　leads　to　a　slight　etching　of　the　Si　film,　and　some　slight　concaves　are　formed.　These　concaves　are　magnified　during　the　boron　doping　and　the　second　deep　etching.　Finally,　the　micro-etching　holes　are　formed　on　the　Si　film.　The　reason　for　the　formation　of　etching　holes　was　analyzed,　and　solutions　were　proposed,　then　a　repeatable　film　fabrication　process　was　formed.