Considering　the　important　influence　of　the　deposition　pressure　on　the　growth　of　thin　films,　such　as　deposition　rate,　crystalline　volume　fraction　and　density,　etc.,　and　based　on　the　analysis　of　the　advantages　and　disadvantages　on　the　mono-pressure　method,　we　proposed　a　new　method　of　high-　and　low-pressure　combination　to　prepare　hydrogenated　microcrystalline　silicon　(mu　c-Si:H)　films,　i.e.　at　first　we　used　high　pressure　to　deposit　film　in　2　min　in　order　to　minish　the　thickness　of　incubation　layer　from　the　amorphous　phase　transition　to　crystalline　phase,　and　then　used　low　pressure　to　deposit　film　in　18　min　to　improve　the　density　and　decrease　the　oxidation　of　the　film.　The　experimental　results　showed　that　using　this　new　method　the　thin　film　with　high　crystalline　volume　fraction　of　61%　and　low　light-induced　degradation　ratio　of　5.6%　at　210　min　was　obtained,　and　meanwhile,　it　also　possessed　higher　density　and　better　photoelectronic　properties　than　mono-pressure　method.　(C)　2008　Elsevier　Ltd.　All　rights　reserved