A method for forming a semiconductor device comprises forming a fin on a substrate and forming a sacrificial gate over a channel region of the fin. A hydrogen terminated surface is formed on sidewalls of the sacrificial gate, and a spacer is deposited on the hydrogen terminated surface of the sacrificial gate. An insulator layer is formed over portions of the fin. The sacrificial gate is removed to expose the channel region of the fin, and a gate stack is formed over the channel region of the fin.