Described is a method of manufacturing a gate-all-around electronic device. The method includes forming a thermal oxide layer though an enhanced in situ steam generation process in combination with atomic layer deposition of a low-κ layer. The thin thermal oxide layer passivates the interface between the silicon layer and the dielectric layer of the GAA. A passivation process after the deposition of the low-κ layer reduces the bulk trap and enhances the breakdown performance of the GAA transistor.