adiabatic technologies
DESCRIPTION
TRANSCRIPT
1
Adiabatic deposition of
films/coatings and adiabatic
surface modification of
materials
Dr. Sergey Korenev
2
Content
1. Introduction.
2. Main principles of adiabatic
technologies.
3. Examples of applications.
4. Conclusion.
3
Goal and motivation
• Information about new method of deposition of films and coatings and surface modification of materials by pulsed beams.
4
Main concept
Energy storageCapacitor
E = CU2/2
ELECTRO-KINETIC TRANSFORMER
OF ENERGY
Charge particle
transformerE = N*mv2/2
Object -
condensed
matter
Potential
energy
Kinetic
energy
Dissipation
of energy
Small size of particles, high speed,
penetration and depth of penetration
depends on kinetic energy
5
Definition of adiabatic processes for
materials
• The main parameter of this process ( technology) is
time:
where: tbeam is pulse duration of energy source, tthermal is
time of dissipation of energy – heating, h is depth of
penetration for energy source in irradiated sample;
,C, are respectively density, heat capacity and heat
conductivity of target.
Chtt thermbeam
22
6
Electrons
][][
][Gray
kg
J
baL
NtIU
m
ED
opt
p
7
Example of adiabatic re-crystallization
of materials by e-beam A
bso
rbed
e-b
ea
m
do
se
Distance
Tem
pera
ture
gra
die
nt
E-beam
Sample
Penetration of
beam: X =F ( W)
time
time
Beam
current
Temperature
1
2
3
8
Re-crystallization
Semiconductor HTSC
9
Ion beams
• The difference between electrons consists
in the different mass and different depth of
penetration of ions to matter.
• Types of ions: all periodical element table.
10
Pulsed ion/electron diode method for
deposition and modification of films
Marx pulsed
high voltage
generator
Ion/Electron
Diode
Substrate
Vacuum
system
Anode/
Cathode
Cathode/
Anode
Control and
monitoring
system
Holder
11
tvoltage<tion
Voltage
Ion current time
timeVoltage
tvoltage>tion
Ion current
Full current of
diode
time
time
time
Main processes:
•Cleaning of surface of substrate by
first pulse ion beam as a result of
ions bombardment.
•Ion mixing of deposited layers with
substrate until the kinetic energy
ions will be enough for penetration.
Typically it is few tens –hundred
layers and depends on type of ion
and material of film.
*Deposition of films and growing of
film structure on the substrate
without heating.
12
Mixing of film and substrate
13
Economical question
1. Cost of equipment: $M 0.05-1.0
2. Efficiency: 75-80%.
3. Time of treatment: from single pulse to 5-
10 minutes ( in compared with diffusion
process few hours).
Disadvantages:
1. Qualified operation.
14
Applications of adiabatic
technologies
• Metals and alloys.
• Semiconductors.
• Polymers and dielectrics.