Electrical characterization of Al 2 O 3 on Si from thermally oxidized

The scaling limit for VLSI gate oxide (SiO 2 ) is 15}20 As that is determined by the large direct-tunneling leakage current. Further scaling to improve device performance can be obtained using a higher dielectric constant material. We have studied the Al 2 O 3 to use as an alternative gate dielectric. To ensure good quality, Al 2 O 3 is thermally oxidized from MBE-grown AlAs or Al on Si-substrates. Experimental results indicate that the leakage current from oxidized AlAs is larger than that from directly oxidized Al, which may be due to the weak As 2 O 3 inside Al 2 O 3 . The leakage current of a 53 As Al 2 O 3 is already lower than that of SiO 2 with an equivalent oxide thickness of 21 As . ( 1999 Published by Elsevier Science B.V. All rights reserved.