who are we? charged particle optics group. what we want 1. pattern dimensions: nm-scale single atom!...
TRANSCRIPT
Our approach(nm-sized patterns & any material)
simulation
EBID experiments
surface science
Rutgers Univ.
Howard Fairbrother, Johns Hopkins Univ.
Our approach(nm-sized patterns & any material)
modelling
EBID experiments
surface science
Rutgers Univ.
Howard Fairbrother, Johns Hopkins Univ.
our simulation: <1 nm!
literature: >15 nm
EBID resolution
transmissionelectron
microscope
Poisson distributions
0.0
0.1
0.2
0.3
0.4
-5 0 5 10 15 20Deposit mass (arb. units)
Num
ber
of o
ccur
ance
s (n
orm
aliz
ed)
0.250 s0.125 s0.060 s0.030 s
Dwell time
Deposit mass distributions
Volume per λ: 0.4 nm3
Volume of W(CO)6 molecule: 0.22 nm3
Our approach(nm-sized patterns & any material)
modelling
EBID experiments
surface science
Rutgers Univ.
Howard Fairbrother, Johns Hopkins Univ.
our simulation: <1 nm!
literature: 15 nm
EBID resolution
transmissionelectron
microscope
TPD experiments
XPS, RAIRS, MS
Better understanding:
dissociation mechanism
Step 1. Cool Au sample to ~120 K and expose
to precursor gas.
gas nozzle
Step 2. Heat in front of QMS while the QMS
monitors m/z = 289
0
2
4
6
8
10
-150 -100 -50 0 50 100 150Temperature (C)
Inte
nsity
m/z
= 2
89 (
a. u
.)
7260483630241812642
gas exposure
x 10-9Torr x 100s
0
2
4
6
8
10
-150 -100 -50 0 50 100 150Temperature (C)
Inte
nsity
m/z
= 2
89 (
a. u
.) 5448423630241812 6 4 3 1
gas exposure
x 10-9Torr x 100s
Step 1. Cool Au sample to ~120 K and expose
to precursor gas.
gas nozzle
Step 2. Heat in front of QMS while the QMS
monitors m/z = 289
0.0
0.5
1.0
1.5
2.0
2.5
-200 -100 0 100 200 300Temperature (C)
Inte
nsity
(ar
b. u
nits
) 0s20s40s60s80s100s180s 0
0.20.40.60.8
1
0 4 8 12
e- dose (x1015 cm2)
A/A
0
Step 1. Cool Au sample to ~120 K and expose
to precursor gas.
gas nozzle
Step 3. Heat in front of QMS while the QMS
monitors m/z = 289
Step 2. Irradiate with electrons (broad beam)
e-gun
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
1 10 100 1000Electron energy (eV)
Cro
ss s
ect
ion
(x
1016
cm
2 )
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
1 10 100 1000Electron energy (eV)
Cro
ss s
ect
ion
(x
1016
cm
2 )
Dissociative electron
attachment
Dipolardissociation
Directionization