Comparative Study of Diamond-Comparative Study of Diamond-like Carbon Films Deposited like Carbon Films Deposited from Different Hydrocarbon from Different Hydrocarbon SourcesSources

Se Jun Park, Kwang-Ryeol Lee

Future Technology Research DivisionKorea Institute of Science and Technology

The International Conference OnMetallurgical Coatings And Thin films

ICMCTF 2006

Various Applications of DLC FilmVarious Applications of DLC Film

Im

pact

Ene

rgy

(eV

)

1

10

100

1000

HydrocarbonSource

DenseHydro-Carbon

PolymerPolymerLikeLike

CarbonCarbon

PlasmaPolymers

Energy

Ion Source

Cold Substrate

The Effect of Ion Energy on the The Effect of Ion Energy on the Structure of DLC FilmsStructure of DLC Films

bVIon Energy

P

GraphiticCarbon

Hydrocarbon Source for DLC FilmHydrocarbon Source for DLC Film

• CH4 (Alkane)

• C6H6 (Aromatic) • C6H14 (Alkane)

• C2H2 (Alkyne)

Previous Works

A. Grill et al. DRM (1993) 2 1519

High mean ion energyHigh free H to C ratio

High Stress

acetylene

methane

methane

cyclohexane

cyclohexane

acetylene

Previous Works

K.-R. Lee et al. Diamon.Rel.Mater. 1994(3) 1230

• Methane (CH4) • Benzene (C6H6)

CH4 : CH5+ or C2H5

+

C6H6 : C6H6+ Difference of

Ion energy

Carbon atom

MotivationMotivation

• C6H6 (Aromatic) • C6H14 (Alkane)

Same carbon atom numbers Different hydrocarbon structure ?

Purposes of Present WorkPurposes of Present Work

To characterize DLC films from the hydrocarbon source of the different structure

• Hexane (C6H14) : Alkane structure

• Benzene (C6H6) : Aromatic structure

To find the relation between the properties of DLC films and the structure of hydrocarbon source

Deposition ConditionDeposition Condition

•RF PACVD(13.56 MHz)

•Precursor Gas : C6H6, C6H14

•Deposition Pressure : 1.33 Pa

•Bias Voltage : - 200 - 800 V

•Substrate : P-type (100) Si-wafer

•Film Thickness : 500 nm

Growth Rate of DLC Films

Mechanical Properties of DLC Films Mechanical Properties of DLC Films from Hexane and Benzenefrom Hexane and Benzene

• Residual Stress • Hardness

FT-IR Spectra of DLC FilmsFT-IR Spectra of DLC Films

• Benzene • Hexane

sp1 C-Hsp2 C-H

sp3 C-H

sp1 C-Hsp2 C-H

sp3 C-Hsp2 C=C sp2 C=C

FT-IR Spectra of DLC FilmsFT-IR Spectra of DLC Films

• Benzene • Hexane

sp1 C-Hsp2 C-H

sp3 C-H

sp1 C-Hsp2 C-H

sp3 C-Hsp2 C=C sp2 C=C

Binding Energy of Hydrocarbons

Organic Chemistry, J. McMurry (2004)

Ch. Wild et al. JVST A. 5 (1987) 2227

420 KJ/mole355 KJ/mole 464 KJ/mole

Dependence of properties of DLC film on precursor gases

Binding Energy of Methane

438 KJ/mole

Dependence of properties of DLC film on precursor gases

• Methane (CH4)

K.-R. Lee et al. Diamon.Rel.Mater. 1994(3) 1230

• Hexane (C6H14),Benzene (C6H6)

ConclusionsConclusions

The structure and properties of DLC films were strongly dependent on the precursor gases.

• Energy per mass of ion was the main factor to determine the properties and structure of DLC films

• As the average ion energy increased, properties of DLC film deposited from the hydrocarbon sources in same functional group showed similar dependence on ion energy.

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