A　high　electron　mobility　transistor　(HEMT)　device　with　ZnO　nanowires　as　light　sensing　gate　is　successfully　prepared　by　hydrothermal　growth　method.　The　HEMT　is　etched　under　source　drain　(S/D)　with　an　etching　depth　of　120/150　nm　to　explore　the　effects　of　different　S/D　etching　depths　on　the　device　performance.　At　the　same　time,　ZnO　crystal　seed　layer　is　deposited　on　the　gate　electrode　by　magnetron　sputtering.　The　hydrothermal　growth　time　is　controlled　to　6/8/10　h　at　80℃　to　explore　the　effects　of　different　hydrothermal　growth　time　on　the　surface　morphology　of　ZnO　nanowires　and　the　UV　detection　performance　of　HEMT.　The　results　show　that　compared　with　conventional　devices,　ZnO　nanowire　gate　devices　have　higher　optical　absorptivity　in　the　wavelength　range　of　350~450　nm.　Under　the　same　hydrothermal　growth　time,　when　the　etching　depth　is　150　nm,　the　source　drain　saturation　current　is　smaller　than　that　of　120　nm,　but　the　saturation　current　difference　under　dark/ultraviolet　light　is　larger,　up　to　8　mA,　showing　higher　detection　efficiency　for　ultraviolet　light.　When　the　hydrothermal　growth　time　is　controlled　to　6　h,　the　growth　morphology　of　nanowires　is　good,　and　when　the　etching　depth　is　150　nm,　the　optical　response/recovery　time　of　the　device　reaches　the　minimum,　which　are　0.005　7　s　and　2.128　s　respectively.　©　2023　Chinese　Institute　of　Electronics.　All　rights　reserved.