In and N2 at 550 °C, forcing CVD of InN to be done at lower temperatures than AlN and GaN which is carried out at 800-1000 °C. The lower CVD temperature should give a lower degree of decomposition of NH3 to N2 and H2 and therefore require a lower NH3/InMe3 ratio, but the opposite is required; CVD of InN uses NH3/InMe3 of 10 000 -100 000. Previous studies on NH3 decomposition kinetics shows that the decomposition is limited, especially at lower temperatures. found that at close to atmospheric pressure and at temperatures between 1123 and 1423 K less than 25 % NH3 had decomposed at residence times of 50-800 ms. These studies do not show an in-depth investigation of the chemistry over a wide range of conditions obtainable during CVD.