$adddiffusivedope

$adddiffusivedope is the command to put diffusive dopant distribution in the device. The doping density decay can be either exponential decay or Gaussian distribution. The command is

$adddiffusivedope
N_region
type  regionID Ndope  activation_energy  x_left  y_bottom  x_right y_top $L_x$ $L_y$  
type  regionID Ndope  activation_energy  x_left  y_bottom  x_right y_top $L_x$ $L_y$  
...
...
Nth_type ....  

type: Can be 1, 11, 111, 101. Please see below
regionID:  The region No to use the diffusive doping
Ndope: Na pr Nd  Posive is for n-type, negative is for p-type
$alphax$ and $alphay$ is the diffusion length in x and y direction. The unit is $\mu m$

For type = 1, inside regionID
x_left < x < x_right  y_bottom < y < y_top :  $N_{d,a}=Ndope$
x < x_left    : $N_{d,a}=N_{d,a}+Ndope*exp(-1/L_x*(|x-x_{left}|))$ 
x > x_right   : $N_{d,a}=N_{d,a}+Ndope*exp(-1/L_x*(|x-x_{left}|))$ 
y < y_bottom  : $N_{d,a}=N_{d,a}+Ndope*exp(-1/L_y*(|y-y_{bottom}|))$ 
y > y_top     : $N_{d,a}=N_{d,a}+Ndope*exp(-1/L_y*(|y-y_{top}|))$
For type = 11, inside regionID
x_left < x < x_right  y_bottom < y < y_top :  $N_{d,a}=Ndope$
x < x_left    : $N_{d,a}=Ndope*exp(-1/L_x*(|x-x_{left}|))$ 
x > x_right   : $N_{d,a}=Ndope*exp(-1/L_x*(|x-x_{left}|))$ 
y < y_bottom  : $N_{d,a}=Ndope*exp(-1/L_y*(|y-y_{bottom}|))$ 
y > y_top     : $N_{d,a}=Ndope*exp(-1/L_y*(|y-y_{top}|))$

As shown in above equation, the difference between 11 and 1 is that for, the diffusive dopant is additional to the regionID. For example, in parameters, you already set doping density to be -1.0e19. If you use 1, Ndope = 2.0e19. Then the final doping density in this region is 2e19-1e19 = 1.0e19. If you use 11, the doping density becomes 2e19

For 101 and 111, it is applied in impurity. The difference between N_impuriy and N_{d,a} is that N_impuriy is 100% activated.

For type = 101, inside regionID
x_left < x < x_right  y_bottom < y < y_top :  $N_{impurity}=Ndope$
x < x_left    : $N_{impurity}=N_{impurity}+Ndope*exp(-1/L_x*(|x-x_{left}|))$ 
x > x_right   : $N_{impurity}=N_{impurity}+Ndope*exp(-1/L_x*(|x-x_{left}|))$ 
y < y_bottom  : $N_{impurity}=N_{impurity}+Ndope*exp(-1/L_y*(|y-y_{bottom}|))$ 
y > y_top     : $N_{impurity}=N_{impurity}+Ndope*exp(-1/L_y*(|y-y_{top}|))$
For type = 111, inside regionID
x_left < x < x_right  y_bottom < y < y_top :  $N_{impurity}=Ndope$
x < x_left    : $N_{impurity}=Ndope*exp(-1/L_x*(|x-x_{left}|))$ 
x > x_right   : $N_{impurity}=Ndope*exp(-1/L_x*(|x-x_{left}|))$ 
y < y_bottom  : $N_{impurity}=Ndope*exp(-1/L_y*(|y-y_{bottom}|))$ 
y > y_top     : $N_{impurity}=Ndope*exp(-1/L_y*(|y-y_{top}|))$