Top injection reactor tool with in situ spectroscopic ellipsometry for growth and characterization of ALD thin films

Ta–N based thin films were grown by thermal atomic layer deposition (ALD) with an alternating supply of the reactant source TBTDET (tert-butylimidotris(diethylamido)tantalum) and NH3 (ammonia). The films were deposited using a newly designed and constructed atomic layer deposition prototype tool combined with several in situ metrology. It was observed that thin films were successfully deposited on a 300 mm Wafer with a saturated growth rate of approximately 0.55 Å/cycle at 270 °C. The as deposited films resulted in the formation of Ta(C)N consisting of 38 at% Ta, 32 at% N and 10 at% C. With in situ spectroscopic ellipsometry (SE) the growing behaviour of the film was investigated and compared to atomic force microscopy (AFM) images.