(CVD)

,

.

.

(deposition) (etching)

,

.

, ,

,

(uniform) (reliable)

.

, ,

.

( CVD), ,

.

, CVD

.

.

deposition '' . ,

, CVD

. vapor

, chemical

. ,

(Physical Vapor Deposition, PVD) , CVD

.

,

(CVD)

http://dx.doi.org/10.5757/vacmag.1.3.9

Thin Film Vacuum Process Technology via Chemical Vapor Deposition Methods

Wan-Shick Hong

Vacuumgrowthofthinfilmsviachemicalvapordeposition(CVD)

methods has been extensively used in modern semiconductor

and flat panel display industries. The CVD processes have a wide

range of variation and are categorized according to their working

conditions,powersources,precursormaterials,andsoforth.Basic

components and process steps common to all CVD branches are

discussed. Inaddition,characteristicsandapplicationsof two

majorCVDtechniquesLPCVDandPECVDarereviewedbriefly.

1995 U.C.Berkeley , , (

), . (wshong@uos.ac.kr)

9 _

. CVD

,

CVD

.

~ mTorr

Low Pressure CVD (LPCVD),

Plasma-Enhanced CVD

(PECVD),

Metal-Organic CVD

(MOCVD) .

CVD

CVD

,

1

.

chamber

(gas inlet),

(exhaust),

(substrate holder),

(power source) .

chamber

regulator, chamber

mass flow controller

valve ,

exhaust(throttle) valve

. ,

, ,

,

[1-3].

CVD 2

.

. , (

, , )

.

. ,

(source gas reactant gas)

. , , ,

, (excite)

(activate)

(radical) . ,

,

. CVD

radical ,

radical

.

radical

,

(surface migration)

(network)

.

(by-product)

.

[Fig. 1] Common Components of the CVD system

[Fig. 2] Basic Steps in the CVD Process [1]

Vacuum Magazine 2014 09 September10

Low-Pressure CVD

1000

LPCVD

, transistor gate

(polysilicon), silicon dioxide, silicon nitride

, tungsten, molybdenum,

tantalum [4].

,

.

hot-wall LPCVD 3

3-zone furnace tube [5].

~

mTorr .

600

(thermal decomposition)

.

, ,

step coverage

.

.

, cold-wall system

hot-wall system ( chamber)

.

,

cleaning .

Plasma-Enhanced Chemical Vapor Deposition

, (flexible)

(wearable)

.

(11

3000 mm x 3320 mm2)

. 600~700

. ,

200~300

.

,

.

.

Plasma Enhanced Chemical Vapor Deposition

(PECVD)

display device, .

PECVD electric field()

. Plasma , ,

4 ,

,

.

1%

.

(SiNx)

parallel-plate (capacitively coupled) PECVD

4 [6]. Chamber

aluminum mm

.

heater

susceptor ,

,

showerhead

.

(CVD)

[Fig. 3] Schematic of the LPCVD System [5]

11 _

PECVD

amorphous silicon (a-Si), silicon nitride (SiNx),

silicon oxide (SiOx) . PECVD

electric field

400 . ,

radical

surface mobility

, stoichiometric

composition ( )

x [7].

silane (SiH4) . SiH4

dopant (PH3,

B2H6 ), n-type p-type doping silicon

, H2

microcrystalline silicon (c-Si)

. 550

, amorphous phase

,

. amorphous silicon

dangling bond( ) ,

,

.

dangling bond

, hydrogenated

amorphous silicon (a-Si:H) . 400

H2

,

SiH4

plasma.

5 8 PECVD system .

process chamber .

2m system

2 .

PECVD ,

. Chamber

mean free path ,

. Radical

powder .

flow rate chamber

(residence time) . RF power

growth rate

.

.

Hydrogenated amorphous silicon defect

dangling bond (

) density

RF power ,

.

dangling bond density 1015 cm-3

, 200 ~

[Fig. 4] SchematicoftheCapacitively-CoupledPECVDSystem[6]

[Fig. 5] APECVDSystemUsed in theDisplay Industry [Source:

AppliedMaterials]

Vacuum Magazine 2014 09 September12

300 RF power .

SiH4 , growth rate

1 ~ 10/sec , RF power growth

rate . RF power

SiH4

depletion effect ,

.

PECVD ,

nitride 10 ~ 35 % .

nitride 20

~ 25 % . silicon nitrogen

Si H N H , PECVD

nitride ( 6%) .

3 amorphous random network

(coordination number) 6 = 2.45 . ,

2.45

, . Si

4 N

3 , 2.45

. Si N

3 network

strain . Si H N

H ,

Si/N stoichiometric composition 0.75

, Si 1.7

. Si/N Si - H N

- H Si/N Si

N .

silicon dioxide network O

2 overconstraint

3 random network .

OH H2O

, O Si

. silicon Si H ,

Si OH H2O .

dominant

, PECVD oxide 2 ~

9% .

.

PECVD silicon nitride refractive index 1.8 ~ 2.6,

105 ~ 1021 cm, breakdown field 106 ~ 107

V/cm .

CVD

.

, LCD

(active matrix flat panel

display) CVD

. CVD

.

CVD

.

(CVD)

[1]H.O.Pierson,HandbookofChemicalVaporDeposition:Principles,TechnologyandApplications(MaterialsScienceandProcessTechnology),2ndEd.,WilliamAndrew,(1999).

[2]S.Sivaram,ChemicalVaporDeposition:ThermalandPlasmaDepositionofElectronicMaterials,Springer,(2013).

[3]D.DobkinandM.K.Zuraw,PrinciplesofChemicalVaporDeposition:WhatsGoingonInsidetheReactor,Springer,(2003).

[4]A.Sherman,ChemicalVaporDepositionofMicroelectronics,NoyesPublications,(1999).

[5]R.C.Jaeger,IntroductiontoMicroelectronicFabrication,2ndEd.,PrenticeHall,(2002).

[6]JanSchmidtetal.,Semicond.Sci.Technol.16,164(2001)[7],,,,,,,,

,2,,2014

References

13 _