A process for depositing aluminum nitride is disclosed. The process comprises providing a plurality of semiconductor substrates in a batch process chamber and depositing an aluminum nitride layer on the substrates by performing a plurality of deposition cycles without exposing the substrates to plasma during the deposition cycles. Each deposition cycle comprises flowing an aluminum precursor pulse into the batch process chamber, removing the aluminum precursor from the batch process chamber, and removing the nitrogen precursor from the batch process chamber after flowing the nitrogen precursor and before flowing another pulse of the aluminum precursor. The process chamber may be a hot wall process chamber and the deposition may occur at a deposition pressure of less than 1 Torr.