In:
Japanese Journal of Applied Physics, IOP Publishing, Vol. 44, No. 7S ( 2005-07-01), p. 5811-
Abstract:
The dry etching characteristics of the TaN/HfO 2 gate stack structure using Cl 2 /Ar, Cl 2 /SF 6 /Ar and Cl 2 /SF 6 /O 2 /Ar inductively coupled plasmas (ICPs) were investigated and the etch rates of the TaN and HfO 2 layers and TaN/HfO 2 etch rate selectivities were compared. The results obtained for the TaN/HfO 2 etching by varying the Cl 2 /Ar gas mixing ratio, the top ICP electrode power, and the dc self-bias voltage ( V dc ) in the Cl 2 /Ar plasmas showed that low etch selectivities were obtained, due to the high HfO 2 etch rate. The effects of adding SF 6 to the Cl 2 /Ar plasmas and adding O 2 flow to the SF 6 /Cl 2 /Ar chemistry were investigated for the purpose of improving the etch selectivity. Etch experiments performed by varying the Cl 2 /SF 6 /Ar gas mixing ratio and V dc value in SF 6 /Cl 2 /Ar plasmas, combined with X-ray photoelectron spectroscopy measurements, showed that the etch rates were reduced compared to those in Cl 2 /Ar chemistry, due to the heavy fluorination of the surface, however the etch selectivity was increased, due to a disproportionate decrease in the TaN and HfO 2 etch rates. The addition of O 2 flow to the SF 6 /Cl 2 /Ar plasma also increased the etch selectivity at an O 2 flow rate of 5 sccm, due to the TaN etch rate being increased, while the HfO 2 etch rate remained almost constant.
Type of Medium:
Online Resource
ISSN:
0021-4922
,
1347-4065
DOI:
10.1143/JJAP.44.5811
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
2005
detail.hit.zdb_id:
218223-3
detail.hit.zdb_id:
797294-5
detail.hit.zdb_id:
2006801-3
detail.hit.zdb_id:
797295-7
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