Fundamentals of Chemical Vapor Deposition: Notation Used in the Tutorial
Gases, Kinetic Theory
symbol
standard units
description
alternative units
P
Pa
Pressure
Torr, atm
V
m3
volume
cm3, liter
N
moles
number of moles
R
J/mole K
universal gas constant
liter atm/mole °C, torr liter/mole °C
T
K
temperature
°C
m
kg
molecular mass
gm, amu
k
joules/K
Boltzmann's constant
ev/K, erg/K
v
m/s
molecular velocity
cm/s
c
m/s
average molecular velocity (various)
cm/s
J
#/m2 sec
flux (number crossing unit area/time)
#/cm2 sec
n
#/m3
molecular density
#/cm3
M
g/mole
molar mass
kgm/mole
λ
m
mean free path
cm
a
m
effective molecular diameter
cm
Reactor Analysis
X
[dimensionless]
utilization
Rs
moles/second
surface reaction rate
molecules/second
Ks
m/sec
surface reaction rate constant (first order)
cm/second
S
m2
surface area
cm2
[species]
moles/m3
concentration of species
moles/cm3, molecules/cm3
Q
moles
total reactant
molecules
Fin
m3/sec
volumetric flow in (or out)
cm3/sec
tres
seconds
residence time
tcon
seconds
consumption time
NAv
#/gm mole
Avogadro's number
Mass Transport
D
m2/sec
diffusion constant
cm2/sec
A
m2
cross-sectional area
cm2
Ld
m
diffusion length
cm
L
m
characteristic system length
cm
Pe
[dimensionless]
Peclet number = (feature size/diffusion length)^2
ρm
moles/m3
molar density
moles/cm3
ρ
kg/m3
mass density
g/cm3
U
m/sec
fluid velocity
cm/sec
μ
kg/m sec
viscosity
gm/cm sec = Poise
Re
[dimensionless]
Reynolds number = (feature size/momentum diffusion length)^2
Fsccm
std. cm3/min
molar flow (standard units)
H
m
height of chamber
cm
r
m
radial distance
cm
Rc
m
radius of chamber
cm
Fm
moles/second
molar flow
C
molecules/m3
molar concentration
moles/cm3
LTh
m
Thiele length
cm
ν
m2/sec
kinematic viscosity, μ/ρ
cm2/sec
Heat Transport
cp
J/kgm
heat capacity at constant pressure
J/gm
cvol
J/m3
volumetric heat capacity
J/cm3
Kth
W/m K
thermal conductivity
W/cm K
c
m/s
velocity of light
cm/s
Sigma
W/m2 K4
Stefan-Boltzmann constant
W/cm2 K4
ϵ
[dimensionless]
emissivity
Pm
W/m2
radiated power
W/cm2
d
m
gap between planes
cm
Chemistry
G
Joules/mole
free enthalpy or Gibbs Free Energy
calories/mole
S
Joules/mole K
entropy
calories/mole
E
Joules/mole
internal energy
calories/mole
H
Joules/mole
enthalpy
calories/mole
ΔHvap
Joules/mole
heat of vaporization
calories/mole
Ea
Joules/mole
activation energy
calories/mole
θ
[dimensionless]
fraction of occupied surface sites
RSC
[dimensionless]
reactive sticking coefficient
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