Two Dimensions

Grid Specification - Example 2 Two Dimensions

line x loc=0.0 spac=0.02 tag=top
line x loc=1.0 spac=0.075
line x loc=3.0 spac=0.25
line x loc=6.0 spac=2.0 tag=bot

The first set of lines specifies the grid in the vertical direction. A line is placed at a depth of 0.0um with a nearby spacing of 20nm. The spacing will be graded out to 75nm at a depth of 1.0um. It is further increased to 250nm at 3.0um and again to 2.0um at a depth of 6.0um. The first and last lines are tagged "top" and "bot" respectively. These tags can be used in the region command to specify material types rectangle by rectangle.

line y loc=0.0 spac=0.75 tag=left
line y loc=3.0 spac=0.025
line y loc=4.5 spac=0.5
line y loc=6.0 spac=0.025
line y loc=9.0 spac=0.75 tag=right

This next set of lines define the lateral spacing. The structure is 9.0um wide, with the finest grid of 250Ã… placed at the lateral positions of 3.0um and 6.0um. The spacing is increased away from these points both toward the middle and toward the edges. The left and right edges are tagged "left" and "right", respectively.

region silicon xlo=top xhi=bot ylo=left yhi=right

This region command sets the material type of the contained rectangle from tagged lines "left", "right", "top", and "bottom" to silicon. In this example, this is the entire mesh.

init

The initial structure is assembled and completed. No initial doping was specified, so the sample starts undoped. A gas mesh is added across the top line at the lowest value in the vertical direction. Interface meshes are built. Because both x and y directional lines were specified, a two-dimensional grid is constructed.

If you'd like to save your structure out at this point, you can use (one of these)

struct outf=filname.str;#saves to current directory
struct outf=OTHER/PATH/filename.str;#save to any directory you want

You can read this back in later using

init inf=filname.str;#or similar