$addanisomobility

$addanisomobility is the command to replace the const mobility setting in the $parameter setting. It is used for carriers with different mobility in different directions.

$addanisomobility
$m{u}_{n,x}m{u}_{n,y}m{u}_{p,x}m{u}_{p,y}$ 
$m{u}_{n,x}m{u}_{n,y}m{u}_{p,x}m{u}_{p,y}$ 
$m{u}_{n,x}m{u}_{n,y}m{u}_{p,x}m{u}_{p,y}$ 
$m{u}_{n,x}m{u}_{n,y}m{u}_{p,x}m{u}_{p,y}$ 
$m{u}_{n,x}m{u}_{n,y}m{u}_{p,x}m{u}_{p,y}$ 
$m{u}_{n,x}m{u}_{n,y}m{u}_{p,x}m{u}_{p,y}$ 

If you have n layers (regions), you need to put n lines. The mobility should not be zero.