The influence of N2/H2 and ammonia N source materials on optical and structural properties of AlN films grown by plasma enhanced atomic layer deposition

► Self-limited true ALD growth of AlN films within 100-200 C is reported. ► Saturated chemisorption reactions betweenTMA and NH3 or N2/H2 precursors are achieved. ► The ALD temperature window remained the same for both group-V source materials (NH3 and N2/H2). ► Optical properties of both AlN films were similar except for a slight difference in the optical band edge and optical phonon positions. ► Al-Al bond was detected near the surface of AlN(NH3) samples, whereas AlN(N2/H2) films exhibited Al-N bond only.