Fe-doped　high-resistivity　GaN　films　and　AlGaN/GaN　high　electron　mobility　transistor　(HEMT)　structures　have　been　grown　on　sapphire　substrates　by　metal　organic　chemical　vapor　deposition.　The　lattice　quality,　surfaces,　sheet　resistances　and　luminescent　characteristics　of　Fe-doped　high-resistivity　GaN　with　different　Cp2Fe　flow　rates　are　studied.　It　is　found　that　high　resistivity　can　be　obtained　by　Fe　impurity　introduced　Fe3+/2+　deep　acceptor　level　in　GaN,　which　compensates　for　the　background　carrier　concentration.　Meanwhile,　Fe　impurity　can　introduce　more　edge　dislocations　acting　as　acceptors,　which　also　compensate　for　the　background　carrier　concentration　to　some　extent.　In　a　certain　range,　the　sheet　resistance　of　GaN　material　increases　with　increasing　Cp2Fe　flow　rate.　When　the　Cp2Fe　flow　rate　is　100　sccm　(1　sccm　=　1　mL　/min),　the　compensation　efficiency　decreases　due　to　the　self-compensation　effect,　which　leads　to　the　fact　that　the　increase　of　the　sheet　resistance　of　GaN　material　is　not　obvious.　In　addition,　the　compensation　for　Fe　atom　at　the　vacancy　of　Ga　atom　can　be　explained　as　the　result　of　suppressing　yellow　luminescence.　Although　the　lattice　quality　is　marginally　affected　while　the　Cp2Fe　flow　rate　is　50　sccm,　the　increase　of　Cp2Fe　flow　rate　will　lead　to　a　deterioration　in　quality　due　to　the　damage　to　the　lattice,　which　is　because　more　Ga　atoms　are　substituted　by　Fe　atoms.　Meanwhile,　Fe　on　the　GaN　surface　reduces　the　surface　mobilities　of　Ga　atoms　and　promotes　a　transition　from　two-dimensional　to　three-dimensional　(3D)　GaN　growth,　which　is　confirmed　by　atomic　force　microscope　measurements　of　RMS　roughness　with　increasing　Cp2Fe　flow　rate.　The　island　generated　by　the　3D　GaN　growth　will　produce　additional　edge　dislocations　during　the　coalescence,　resulting　in　the　increase　of　the　full　width　at　half　maximum　of　the　X-ray　diffraction　rocking　curve　at　the　GaN　(102)　plane　faster　than　that　at　the　GaN　(002)　plane　with　increasing　Cp2Fe　flow　rate.　Therefore,　the　Cp2Fe　flow　rate　of　75　sccm,　which　makes　the　sheet　resistance　of　GaN　as　high　as　1　x　10(10)　Omega/square,　is　used　to　grow　AlGaN/GaN　HEMT　structures　with　various　values　of　Fe-doped　layer　thickness,　which　are　processed　into　devices.　All　the　HEMT　devices　possess　satisfactory　turn-off　and　gate-controlled　characteristics.　Besides,　the　increase　of　Fe-doped　layer　thickness　can　improve　the　breakdown　voltage　of　the　HEMT　device　by　39.3%,　without　the　degradation　of　the　transfer　characteristic.