title 'GaN HEMT Double 1um Gate Time Dependent'

Coordinates
  cartesian3
variables
    Temp !(threshold=0.1)

select initgridlimit=0 smoothinit=off

definitions
k          { thermal conductivity -- values supplied later }
kgan=0.00021 {hexagonal GaN, W/um-K}
ksic=0.00049 {6H-SiC}
kau=0.000381 {Gold }
kcu=0.000401 {Cu}
kair=0.0000000257
Q          { Thermal source }
h=3e-11   {Heat transfer coefficient, here 30 W/m2-K = 30*10-12 W/um2-K}
Rho
RhoSic=3.211e-9 {g/um^3}
RhoCu=8.94e-9
RhoAu=19.30E-9
RhoGaN=6.1e-9
Cp
CpSic=1.09 {J/molK}
CpGaN=35.3 {*can be temperature dependent Cp=32.960+0.162*10^-1*Temp+2360170T^-2-775370000T^-3  Tomaskiewicz et al. "Heat Capacity of GaN" Journal of Thermal analysis and colorimetry}
CpCu=24.44
CpAu=25.418

! comment this out on first run:
transfermesh("afrl_mesh_2.xfr")

initial values
    Temp = 60+40*exp(-z/100)

equations
 div ( k * grad(Temp) ) + Q = Rho * Cp * dt(Temp)
   ! div[k*grad(Temp)] + Q = 0        { the heat equation }
Extrusion
Surface 'Bottom' Z=0
Layer 'Package'
Surface 'Substrate' Z=630
Layer 'SiC'
Surface 'Buffer' Z=880
Layer 'GaN'
Surface 'Active Layer' Z=882.248
Layer 'Channel'
Surface 'Contact' Z=882.268
Layer 'Gate'
Surface 'Top' Z=882.298

BOUNDARIES
Surface 'Bottom' Value(temp)=100
Surface 'Top' Natural(temp)=h*(25-temp)



Region 1 'SiC'
Layer 'Package' k=kcu Q=0 Rho=RhoCu Cp=CpCu
Layer 'SiC'  k=ksic Q=0 Rho=RhoSic Cp= CpSic
Layer 'GaN' k=kgan Q=0 Rho=RhoGaN Cp=CpGaN
Layer 'Channel' Void
Layer 'Gate' Void
start (-487.5,-1212.5)
line to (-487.5,1212.5)
	to (487.5,1212.5)
	to (487.5,-1212.5)
	line to close


Limited Region 3 'Active Area'
!Layer 'Package' Void !k=kcu Q=0 Rho=RhoCu Cp=CpCu
!Layer 'SiC' Void !k=ksic Q=0  Rho=RhoSic Cp=CpSic
!Layer 'GaN' Void !k=kgan Q=0  Rho=RhoGaN Cp=CpGaN
Layer 'Channel' k=kgan Q=0.898  Rho=RhoGaN Cp=CpGaN
Layer 'Gate' k=kau Q=0 Rho=RhoAu Cp=CpAu
start (-16,-80)
line to (-16,80)
	to (-15,80)
	to (-15,-80)
	line to close

start (15,-80)
line to (15,80)
	to (16,80)
	to (16,-80)
	line to close


TIME 0 TO 1 ! by 1   { if time dependent}
plots
 	
!for t=1
for cycle=10
grid(x,y,z)
grid(x,z) on y=0
grid(y,z) on x=0
grid(x,y) on "Active Layer"
contour(TEMP) painted on "Active Layer"  as "XY Temp"
 contour(TEMP) painted on x=0  as "YZ Temp"
contour(TEMP) painted on y=0  as "XZ Temp"
 elevation(TEMP) painted from (-488,0,0) to (488,0,0)  as "X-Axis Temp" !range=(0,tmax)
      elevation(TEMP) painted from (0,-1213,0) to (0,1213,0)  as "Y-Axis Temp" !range=(0,tmax)
      elevation(TEMP) painted from (0,0,0) to (0,0,883)  as "Z-Axis Temp" !range=(0,tmax)}
 surface(temp) on x=0
surface(temp) on y=0
surface (temp) on "Active Layer"

for t=0,endtime  transfer(temp) file="afrl_mesh.xfr"

end