A method for manufacturing a semiconductor device includes forming a channel layer on a semiconductor substrate and forming at least two spacers on the channel layer. A first portion of a gate metal layer is formed between the spacers, and a dielectric layer is conformally deposited on the spacers and the first portion of the gate metal layer. In the method, part of the dielectric layer is directionally removed from surfaces which are parallel to an upper surface of the substrate. A second portion of the gate metal layer is formed between remaining portions of the dielectric layer and on the first portion of the gate metal layer, and a cap layer is deposited on the second portion of the gate metal layer. A lateral width the second portion of the gate metal layer is less than a lateral width of the first portion of the gate metal layer.