NMOS (N-channel metal oxide semiconductor) device, with GaAs material growing in silicon grooves, based on ART (aspect radio trapping ) structure

The invention discloses a preparation method of an NMOS (N-channel metal oxide semiconductor) device and the corresponding NMOS device. The preparation method includes the steps of S1, selecting a silicon substrate which deviates 6-10 degrees in a direction from (100) to (111), and growing a SiO2 layer on the silicon substrate; S2, etching the SiO2 layer to form a plurality of grooves with aspect ratio larger than 2 on the SiO2 layer, and allowing the bottom of each groove to be exposed out of the silicon substrate; S3, under a growth pressure of 100-150 mBar, using a MOCVD (metal organic chemical vapor deposition) process to sequentially grow a barrier layer, a buffer layer and a top layer in each groove; and S4, producing a source, a drain and a grid on each top layer. Mismatch dislocation at an interface and antiphase domain boundary are stopped at a SiO2 wall, hetero-junction interface defect extension is restrained effectively, epitaxial layer quality is improved, and good device quality is achieved when an epitaxial layer is used at the substrate of the NMOS.