X
Concentration depth profiling of a heavily-boron-doped Si substrate
**
*
K. Kakushima, J. Kanehara, K. Tsutsui, T. Hattori, H. Iwai
IGSSE, Tokyo Institute of Technology
*FRC, Tokyo Institute of Technology
1
Lg
Plasma
Doping
SIMS profiles of plasma doped (PD) samples
K. Tsutsui et al., JAP, 104 (2008) 093709.
w/o RTA
Anneal
Diffusion
Xj
after spike-RTA
year 2011 2012 2013 2014 2015
L g
(nm) 24 22 20 18 17
Xj (nm) 10.5 9.5 8.7 8.0 7.3
(ITRS 2010 update, High performance)
+FLA
2
p +
K. Tsutsui et al., JAP, 104 (2008) 093709.
hν=500eVXXPS
(SPring-8 BL27SU)
B1s
B1s, Si2p 3/2
IMFP1nm
B
Si0.5nm
XPSB
30nmSIMS
3
I
⎛ x ⎞
= ∫ ∞ ⎜ − ⎟
0
⎝ λ sinθ
⎠
( z) A c( z + x) σ exp dx
dI
dz
c: σ:
λ: IMFP, A: , θ:
( z) c( z + x)
⎛ x ⎞
= A∫ ∞ σ exp⎜
− ⎟dx
0 dz ⎝ λ sinθ
⎠
z=0
z
(x=0)
x
contribute
for I(z)
c(z)
⎡ = Aσ
⎢ − c ∫ ∞ ⎜ ⎟dx
⎣ λ sinθ
0
⎝ λ sinθ
⎠
A
= −Aσc( z) + I( z)
λ sinθ
1 dI
( )
( z)
1
1
c z = − + I( z)
c0 Aσ
dz λσ sinθ
=
1
⎛ x ⎞ ⎤
( z) + c( z + x) exp − ⎥ ⎦
I
λσ sinθ
( z)
4
(abruptness)
Undrestimation of surface
concentration, c 0 /c(z)
1.0
0.8
0.6
0.4
0.2
λsinθ=0.5nm
c
c
0
= a a
λsinθ=1.0nm
( z) + ln( 10) λ sinθ
0
0 2 4 6 8 10
Abruptness (a), (nm/decade)
c
B concentration (cm -3 )
( z)
= −
10 22
10 21
10 20
10 19
10 18
10 17
1 dI
Aσ
dz
( z)
1
+ I
λσ sinθ
steep profile at surface
after RTA
before RTA
SIMS
10 16 0 5 10 15 20 25 30 35
Distance from surface (nm)
( z)
λsinθ
Spike-RTA34nm/dec.
5
1.
2. SiO 2
XPS
B 2 H 6 (He)
(as doped)
spike-RTA:1075 o C
SPring-8 BL26SU
hν=500eV, B1s, Si2p
TOA=15~80 o
6
O 3 HF
(0.5nm)
XPS
c
c
0
=
( z)
TOA: θ=80 o
1
I
λσ sinθ
= −
( z)
1 dI
Aσ
dz
( z)
1
+ I
λσ sinθ
B concentration
( z)
(x10 21 cm -3 )
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0 1 2 3 4 5
Depth (nm)
Si
7
1.
2. /SiO 2
D.-A. Luh et al., Phys. Rev. Lett. 79, 3014 (1997).
3. Si2pSi2p 3/2
G. Hollinger et al., Appl. Phys. Lett., 44, pp. 93-95 (1984).
4. SiO 2 SiBλ1.18, 1.00nm
5. σ(Si2p 3/2 )/σ(B1s)=3.18
SiO 2
T. Hattori, et al., J. Vac. Sci. Technol., B 11, 1528-1532 (1993).
S. Tanuma et al., Surf. Interface Anal., 17, pp. 927-939 (1991).
J. J. Yeh and I. Lindau, At. Data and Nucl. Data Tables 32, 1 (1985).
6. SiO 2 B
d
Si
φ
θ
I(SiO 2 )
I(Si)
7. z=5~10nm
SIMS
8
B1sSi2p
Intensity (Arb. Units)
Intensity (Arb. Units)
before RTA
BO x
B
TOA=80 o
20 o
205 195 180 175
Binding energy (eV)
after RTA
105
after RTA SiO
BO 2
x
B
15 o
TOA=80 o
205 195 180 175
Binding energy (eV)
Intensity (Arb. Units)
Intensity (Arb. Units)
before RTA
TOA=80 o
SiO 2
20 o
Si
110 100 95
Binding energy (eV)
TOA=80 o
15 o
Si
110 105 100 95
Binding energy (eV)
Si2p
9
Intensity ratio (Arb. Units)
I(Si)
I(SiO)
before RTA
after RTA
0 30 60 90
TOA (degree)
SiO 2
SiO 2
0.87nm
λ Si2p3/2,Si
0.24nm
RTA
1.47nm
(SiSi2pIMFP)
0.43nm
Spike-RTA
SiIMFP
10
Intensity ratio (Arb. Units)
I(BO)
I(SiO)
after RTA
before RTA
0 30 60 90
TOA (degree)
RTA
SiO 2
SiO 2
0.87nm
0.87nm
0.60nm
1.5x10 20 cm -3
1.5x10 21 cm -3
0.6nm
Si
11
Si
Intensity ratio (Arb. Units)
after RTA
I(B)
I(Si)
before RTA
0 30 60 90
TOA (degree)
B concentration
(x10 21 cm -3 )
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
0 1 2 3 4 5
Depth (nm)
c(z)
IMFP
λ B1s,Si
0.35nm
(SiB1sIMFP)
0.61nm
Spike-RTA
SiIMFP
12
Si
B concentration (cm -3 )
(x10 21 )
3
2
1
0
-2
SiO 2
surface
surface
-1
0
Si
4.8x10 13 cm -3
3.8x10 13 cm -3
1 2 3 4
Distance from SiO 2 /Si interface (nm)
SiO 2
13
0.8nm
XPS
SiO 2 2
14
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