Silicon carbide (SiC) was etched in a NF3CH4 inductively coupled plasma. The etch process was modeled by using a neural network called generalized regression neural network (GRNN). For modeling, the process was characterized by a 24 full factorial experiment with one center point. To test model appropriateness, additional test data of 16 experiments were conducted. The GRNN prediction performance was optimized by means of a genetic algorithm (GA). Compared to a conventional GRNN model, the GA-GRNN model demonstrated a significant improvement of more than 85%. Predicted model behaviors were highly consistent with actual measurements. From the GA-optimized model, several plots were predicted to examine etch mechanisms. The model predicted that parameter effects are a complex function of plasma conditions. The etch rate was strongly correlated to the variations in the pressure-induced dc bias. This was also illustrated for the variations in the gas ratio.

1.
B.
Kim
,
K.
Kim
, and
B.-T.
Lee
,
Appl. Surf. Sci.
217
,
261
(
2003
).
2.
J. J.
Wang
,
E. S.
Lambers
,
S. J.
Pearton
,
M.
Ostling
,
C.-M
Zetterling
,
J. M.
Grow
, and
R. J.
Shul
,
J. Vac. Sci. Technol. A
16
,
2204
(
1998
).
3.
B.
Kim
and
B. T.
Lee
,
IEEE Trans. Plasma Sci.
30
,
2074
(
2002
).
4.
B.
Kim
,
S.
Kong
, and
B. T.
Lee
,
J. Vac. Sci. Technol. A
20
,
146
(
2002
).
5.
B.
Kim
,
H. J.
Choi
, and
B. T.
Lee
,
J. Vac. Sci. Technol. A
20
,
424
(
2002
).
6.
F. A.
Khan
and
I.
Adesida
,
Appl. Phys. Lett.
75
,
2268
(
1999
).
7.
L.
Cao
,
B.
Li
and
J.
Zhao
,
J. Electrochem. Soc.
145
,
3609
(
1998
).
8.
A.
Tasaka
,
K.
Takahashi
,
K.
Tanaka
,
K.
Shimzu
,
K.
Mori
,
S.
Tada
,
W.
Shimzu
,
T.
Abe
,
M.
Inaba
,
Z.
Ogumi
, and
T.
Tojo
,
J. Vac. Sci. Technol. A
20
,
1254
(
2002
).
9.
R.
Wolf
and
R.
Helbig
,
J. Electrochem. Soc.
143
,
1037
(
1996
).
10.
S. M.
Kong
,
H. J.
Choi
,
B. T.
Lee
,
S. Y.
Han
, and
J. L.
Lee
,
J. Electron. Mater.
31
,
209
(
2002
).
11.
P. H.
Yih
and
A. J.
Steckl
,
J. Electrochem. Soc.
142
,
312
(
1995
).
12.
J. B.
Casady
,
S. S.
Mani
,
R. R.
Siergiej
,
W.
Urban
,
V.
Balakrishna
,
P. A.
Sanger
, and
C. D.
Brandt
,
J. Electrochem. Soc.
145
,
L58
(
1998
).
13.
J. R.
Flemish
,
K.
Xie
,
J. R.
Flemish
, and
K.
Xie
,
J. Electrochem. Soc.
143
,
2620
(
1996
).
14.
P.
Chabert
,
N.
Proust
,
J.
Perrin
, and
R. W.
Boswell
,
Appl. Phys. Lett.
76
,
2310
(
2000
).
15.
R.
Van Roijen
,
C. W. T.
Bulle-Lieuwma
, and
E. A.
Montie
,
J. Vac. Sci. Technol. B
10
,
2188
(
1992
).
16.
B.-T
Lee
,
S.-Y.
Jung
,
J.-L.
Lee
,
Y.-J
Park
,
M.-C.
Paekkk
, and
K.-I.
Cho
,
Semicond. Sci. Technol.
16
,
471
(
2001
).
17.
D. F.
Specht
,
IEEE Trans. Neural Netw.
2
,
568
(
1991
).
18.
D. E.
Goldbeg
,
Genetic Algorithms in Search, Optimization and Machine Learning
(
Addison-Wesley
, Reading, MA,
1989
).
19.
B.
Kim
and
K.
Kim
,
Appl. Surf. Sci.
222
,
17
(
2004
).
20.
D. C.
Montgomery
,
Design and Analysis of Experiments
(
Wiley
, Singapore,
1991
).
You do not currently have access to this content.