26
DEPOSITION
(a-Si) layer, on top of SiO
2
, was etched completely and
uniformly. All the obtained oxide etch rates and oxide etch non
uniformities of the Ar/N
2
/F
2
cleaning gas mixture on SiO
2
are
equal or better than the standard CF
4
based BKM (Best Known
Method) chamber clean of Applied Materials. The Ar/N
2
/F
2
etching rate of amorphous Si was tested, resulting in etch rates
of > 1200 nm/min.
The superior etch rate performance of Ar/N
2
/F
2
gas mixture
was combined with excellent etch non uniformities values. On
Figure 5: View inside the AMAT P5000 chamber lid after the SiO2 the Ar/N
2
/F
2
gas shows a very low etch non uniformity of
repeatability of SiO
2
deposition and Ar/N
2
/F
2
gas cleaning ±3 (1sigma) and on Si
3
N
4
of ±8% (1sigma), respectively. This
runs (total 75 wafers) with the Susceptor and creamed data were achieved for a total of 75 wafers, within as well as
coloured large and small O-rings (a.) as well as the wafer to wafer, demonstrating a very repeatable and stable oxide
shower head (b.). etching rate. The etch non uniformity of C2F6/O2 with ±10%
(1sigma) and NF
3
with ±9% (1sigma) are significant lower
compared to Ar/N
2
/F
2
.
Conclusions The particle performance data of the Ar/N
2
/F
2
cleaning gas,
In this work, an Ar/N
2
/F
2
gas mixture was used with 10% Ar, showed in average just 14 particle adders (0.25µm) generated
20% F
2
and 70% N
2
in order to obtain a maximum of 20% from run to run. The data indicate that no significant particle
fluorine as inert gas. The evaluation of the Ar/N
2
/F
2
gas mixture contamination was induced by the process and Ar/N
2
/F
2
can very
was performed in a 200mm Applied Materials PECVD reactor well be used as a high performance clean etching gas. The tested
on a P5000 main frame. The etch rate and etch non uniformity, mixture Ar/N
2
/F
2
shows improvements in both parameters,
of Ar/N
2
/F
2
on SiO
2
and Si
3
N
4
, respectively, was tested on cleaning at a faster rate, even requiring a lower amount of gas.
standard CVD cleaning gases, like NF
3
, CF
4
and C
2
F
6
/O
2
. The Particularly, the NF
3
cleaning method requires, for SiO
2
repeatability (total 75 wafers) of the Ar/N
2
/F
2
etch rates on SiO
2
processes, a longer cleaning time (+27%) and almost the double
within wafer, wafer to wafer and batch to batch as well as the amount of process gas (+196%). The high etching rate of the
particle performance, has been performed. selected Ar/N
2/
F
2
mixture and the low gas requirement indicate
The highest etching rates of all gases (NF
3
, C
2
F
6
/O
2
, CF
4
) are that a significant Cost of Ownership reduction can be achieved,
achieved by Ar/N
2
/F
2
mixture of 1216 nm/min for SiO
2
and both increasing the tool throughput and reducing the
1850 nm/min for Si
3
N
4
. The Ar/N
2
/F
2
cleaning gas mixture consumables requirement, in comparison with the CF
4
and NF
3
achieved a higher cleaning rates for dielectric films, like SiO
2
based cleaning chemistries that have been tested.
and Si
3
N
4
compared to the standard CF
4
cleaning recipe and an These results have been achieved with a cleaning chemistry
optimised NF
3
chamber clean. Also a 300nm amorphous Silicon with GWP=0. F
2
mixtures are available world wide in standard
cylinders from Solvay Fluor.
REFERENCES: Solid State Technology, 2000.
1] Ronald Hellriege, Bernd Hintze, Hubert Winzig, Matthias [7] Yutaka Ohira, Yuki Mitsui, Taisuke Yonemura, Katsuo
Albert, Johann W. Bartha, Thomas Schwarze and Michael Sakai, Tsuyoshi Takaichi, Tadao Takase, Tatsuro Beppu and
Pittroff, “Feasibility Study for Usage of diluted Fluorine for Akira Sekiya, “Evaluation of fluorine gas as an alternative PE-
Chamber Clean Etch Applications as an Environmental Friendly CVD chamber cleaning chemical”, Research Institute of
Replacement of NF
3
”, Materials Research Society, Volume 914, Innovative Technology for the Earth (RITE) and National
pp. 445, Paper #0914-F09-23, 2006. Institute of Advanced Industrial Science and Technology (AIST),
[2] Charles Allgood, “Delivering Fluorine to the June 2002
Semiconductor Industry; balancing performance, safety, health [8] Stephen H. Siegele, Frederick J. Siegele and Daniel B.
and environmental issues”, Gases and Technology, Hage, “On-Site Generation of High Purity Fluorine as a Safe
September/October 2003. and Economical Alternative for CVD Chamber Cleaning” Future
[3] Franco Blundo, Manfredi Alberghina and Marcello Fab. Intl. Volume 13, July 2002
Frazzica, “Selecting proper chamber-cleaning processes for [9] Nancy Irwin, Graham Hodgson, Brian Zievis, Christopher
installed-base CVD tools”, IEEE/ SEMI Advanced Myers, Susan Orneals and Joe Van Gompel, “Integrated fluorine
Semiconductor Manufacturing conference, April 2005. supply strategy for CVD chamber cleaning applications”,
[4] Walter F. Worth, “Achieving sustainability in the Semiconductor Equipment and Technologies (ISBN # 1-
semiconductor manufacturing industry”, International Sematech 882688-78-4), 2002.
Manufacturing Initiative (ISMI), MicroMagazine, March 2006 [10] Benjamin Jurcik, Jun Sonobe and Jean-Marc Girard,
[5] Oliver F. Schedlbauer and Hubert F. Winzig, “Cost “Improving Thermal cleaning process”, Euro Asia
reduction challenges in CVD chamber cleaning: strategies to Semiconductor, April 2007
reduce gas”, Future Fab Intl., Volume 13, July 2002. [11] Robert Wieland, Handbook of 3D Integration , Vol. 1,
[6] Andrew D. Johnson, William R. Entley, Peter J. Maroulis, chapter 6, ,”SiO2”, edited by P. Garrou/ C. Bower/ P. Ramm,
“Reducing PFC gas emission from CVD chamber cleaning”, (978-3-527-32034-9), to be published in June 2008.
Acknowledgement:
The authors would like to acknowledge Trelleborg Sealing Solutions GmbH (Stuttgart, Germany) for the delivery of excellent F2
resistant O-ring seals (Isolast 9675).
www.euroasiasemiconductor.com August 2008
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44