ALD of Hafnium Dioxide Thin Films Using the New Alkoxide Precursor Hafnium 3-Methyl-3-pentoxide, Hf(mp)4

✍ Scribed by W. Cho; K.-S. An; T.-M. Chung; C. G. Kim; B.-S. So; Y.-H. You; J.-H. Hwang; D. Jung; Y. Kim

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 332 KB
• Volume: 12
• Category: Article
• ISSN: 0948-1907
• DOI: 10.1002/cvde.200506458

✦ Synopsis

A new alkoxide precursor, Hf(mp) 4 [mp = 3-methyl-3-pentoxide, OC(CH 3 )(C 2 H 5 ) 2 ] has been employed in the atomic layer deposition (ALD) of HfO 2 thin films using water (H 2 O) as the oxygen source. The self-limiting ALD process via alternate surface reactions of Hf(mp) 4 and H 2 O is confirmed from thickness measurements of the HfO 2 films grown with varied Hf(mp) 4 supply time and number of Hf(mp) 4 /H 2 O ALD cycles. The ALD temperature window for this precursor is found to be between 250 and 350 °C. Under optimal reaction conditions, the growth rate of the HfO 2 films is ∼0.9 Å per cycle. Amorphous films can be obtained across the entire temperature range with atomically flat and uniform surfaces. X-ray photoelectron spectroscopy (XPS) and depth-profiling Auger electron spectroscopy (AES) indicate that the films are stoichiometric with negligible amounts (less than 2 %) of carbon impurities.