Adiabatic technologies

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Transcript of Adiabatic technologies

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Adiabatic deposition of

films/coatings and adiabatic

surface modification of

materials

Dr. Sergey Korenev

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Content

1. Introduction.

2. Main principles of adiabatic

technologies.

3. Examples of applications.

4. Conclusion.

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Goal and motivation

• Information about new method of deposition of films and coatings and surface modification of materials by pulsed beams.

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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

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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

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Electrons

][][

][Gray

kg

J

baL

NtIU

m

ED

opt

p

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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

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Re-crystallization

Semiconductor HTSC

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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.

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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

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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.

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Mixing of film and substrate

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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.

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Applications of adiabatic

technologies

• Metals and alloys.

• Semiconductors.

• Polymers and dielectrics.