Design of Small Chemical Vapor Deposition System for Materials ...

Shamil Baldeosingh

Dasney Joseph

Walter McKinley


March 4
th

, 2010

EML 4905 Senior Design Project

Advisor: Dr. K. H. Wu

March 24, 2010

1


Background


Problem Statement


Design Specifications


Conceptual Designs


Project Management


Future Plans

2


Chemical Vapor Deposition ( CVD )



Widely used for engineering applications


•
Scalable to industrial production

•
20
-
100 % yield



•
Controllable parameters to determine properties


3


Large Research Interest



Properties

•
Mechanical

•
Electrical

•
Thermal

•
Novel Applications



Variations

•
Dimensions and Geometry

•
Quality and Yield


Zhao
et al.
,
Physical Review Letters
,

4


CNT synthesis for current CVD system


3 hours for sample size of 1
–

5 grams

▪
Furnace heating of entire reaction chamber

▪
Such a large sample size is not necessary for research




CNT synthesis for proposed CVD system


0.5 hours for sample size of less than 1 gram

▪
Localized heating of gases and substrate

▪
Appropriate for research applications



5


Preheated Gas Temperature

•
At least
400

̊c


Substrate Temperature

•
600
-
1000

̊c




6





Volumetric flow Rate
(
mL
/min)

PROCESS GAS

Hydrogen (H
2
)

400

PRECURSOR GAS

Acetylene (C
2
H
2
)

100

CARRIER GAS

Argon (
Ar
)

600


Packaging


Accessibility


Substrate should be easily loaded


Maintenance of system


Gas flow


Reynolds number << 2100 : Laminar Flow


Peclet number << 1


Knudsen number > 1


7

8

9

10

Design A

Straight Tube

Design

B

Variable Cross
Section Tube

Design C

Cube

Packaging

4

4

1

Accessibility

5

5

1

Gas

Flow


3

2

4

Price

1

2

5

Excellent
–

1

Very Good
-
2

Good
–

3


Fair
–

4


Poor
-

5

11


Substrate Material

•
Wafer

•
Powder




Resistive Heating
Element

•
Material

•
Configurations

•
Life span




Thermal Strength

•
Thermal Shock


•
Thermal Expansion

•
Deflection



Power Input

•
AC vs. DC

•
H
-
Current/ L
-
Voltage

•
L
-
Voltage/H
-
Current


12


Heat Generation


Dasney

Joseph



Instrumentation and Fluid Mechanics


Shamil

Baldeosingh



Conceptual Designs and Prototype


Walter McKinley

13

Gantt Chart
-
Spring 2010

14

15

Gantt Chart
-

Fall 2010

16

0
5
10
15
20
25
TIME (hours)

January
February
March
April
SHAMIL

DASNEY

WALTER


Design Modeling

•
SolidWorks



Simulation

•
ANSYS CFX

▪
Fluid Mechanics

▪
Heat Transfer from Resistive
Heating Elements


Instrumentation and
Control

•
LabVIEW

•
Thermocouple

•
Infrared Temperature
Sensor

•
Mass Flow Controller



Prototype Testing

•
Scanning Electron
Microscope ( SEM )

▪
Verify growth of CNT’s


17


Dr. Wu ( Florida International University )


Amit

Datye

( Oak Ridge National Laboratory )


John Hart ( Massachusetts Institute of Technology )



18

19