In:
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, American Vacuum Society, Vol. 30, No. 1 ( 2012-01-01)
Abstract:
For the purpose of extending the upper temperature limit of metallorganic atomic layer deposition, mixed ligand precursors containing cyclopentadienyl (Cp, C5H5) ligands have been shown to exhibitsuperior thermal stability compared to the widely adopted tetrakis(ethylmethylamino)hafnium (TEMAH) precursor while also possessing adequate vapor pressure characteristics for use in atomic layer deposition (ALD) processing. In order to prevent the deleterious oxidation of the underlying Si from O3 the use of a milder oxidant such as H2O is preferred. Accordingly in this study, we investigated ALD using the liquid precursors CpHf(NMe2)3 and (CpMe)2Hf(OMe)Me in the temperature range 305 – 410 °C with H2O as a co-reactant and compared the film growth and electrical properties with films deposited using a conventional TEMAH/H2O process at 305 °C as well as the same process with an optimized annealing scheme. The CpHf(NMe2)3/H2O process was observed toexhibit a growth-per-cycle (GPC) in the range 0.23 – 0.36 Å/cycle which is roughly half that of the TEMAH/H2O process (∼0.6 Å/cycle). In the 340 – 375 °C range this process is comparable toTEMAH/H2O in terms of equivalent oxide thickness but with slightly higher leakage. Even thoughthis process allows for higher processing temperatures it is not able to scale to the level of theTEMAH/H2O process using an optimized annealing scheme. For (CpMe)2Hf(OMe)Me withH2O,in the process space investigated in this study this process was unable to afford a viable growth rate ( & lt;0.03 Å/cycle) for device testing although a GPC of 0.33 Å/cycle was obtained using O3.
Type of Medium:
Online Resource
ISSN:
0734-2101
,
1520-8559
Language:
English
Publisher:
American Vacuum Society
Publication Date:
2012
detail.hit.zdb_id:
1475424-1
detail.hit.zdb_id:
797704-9
