Hydride vapor phase epitaxy of Si-doped AlN layers using SiCl4 as a doping gas

•Si-doped AlN layers were grown by HVPE using SiCl4 as a doping gas.•Linear control of Si concentration was achieved.•Pit- and stress-free Si-doped AlN layers were obtained on bulk AlN substrates.•Si-doped layers showed n-type conductivity with an activation energy of 253 meV.•Introduction of Al vacancy related acceptors compensated the n-type carriers.