Semiconductor devices and methods of forming the same include forming a gate stack over a semiconductor fin. An interlayer dielectric is formed to a height of the gate stack. The interlayer dielectric is etched away in regions outside of junction regions for the semiconductor fin to form first gaps. A dielectric cap is formed over the gate stack and in the first gaps. The remaining interlayer dielectric is etched away to expose a source and drain region of the semiconductor fin. A conductive junction is formed on the semiconductor fin.