According to one aspect of the inventive concept there is provided a process for manufacturing a semiconductor device, comprising: providing a channel layer (104), providing a mask (106) on the channel layer, epitaxially growing a contact layer (108) in contact with the channel layer, epitaxially growing a support layer (110) on the contact layer, wherein the support layer is arranged to be etched at a higher rate than the contact layer, forming a trench extending through the support layer by removing the mask, and providing a conductor (118) in the trench. There is also provided an intermediate product for the manufacture of a semiconductor device.