Surface structures from NH3 chemisorption in CVD and ALD of AlN, GaN and InN films

24 January 2022, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Aluminum nitride (AlN), gallium nitride (GaN) and indium nitride (InN) form a family of technologically important semiconductors of high importance to light-emitting diodes and high frequency electronics. Although thin films of these materials are routinely manufactured by chemical vapor deposition (CVD) and atomic layer deposition (ALD), the methods are far from optimal and knowledge of the underlaying chemical processes are lacking. In this work we performed ab-initio investigations of the surface coverage of these materials under an ammonia rich atmosphere. Periodic density functional theory (DFT) calculations were used to test probable surface structures, their electronic and thermal energies were used to calculate their contribution to the surface composition at temperature and pressure conditions relevant for CVD and ALD processes of these materials. The results show similarities between the group of materials with similar NHx surface structure present for all three. Comparison of the coverage showed that at low growth temperatures the surface is expected to be covered by NH2 while at high temperatures most surface sites would be vacant. The surface structures where all found to be most stable on AlN and least stable on InN. These results are important for further investigations of the material growth mechanisms.


surface chemistry

Supplementary materials

Supporting information
Additional figures


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.