DepositCommand

Synopsis

deposit

rate = <n>
time = <n>
 MaterialType
[spacing = <n>] [grid = <n>] [tolerance = <n>]

Description

rate

This allows the specification of a deposition rate in mm/min.

time

This parameter specifies the length of the deposition step in minutes.

MaterialType

This allows the specification of the material to be deposited. Material specification rules are uniform for all commands.

spacing

This allows the user to set the spacing in the rectangular mesh used for the level set. This controls the accuracy of the level set calculation. Smaller spacings are more accurate, but also more memory and cpu intensive. This is probably not a choice for the faint hearted.

grid

This is the integer number of grid steps to use in the deposition. Grid is laid conformally to the original surface and this gives the number of division in the direction normal to the surface.

tolerance

Desired accuracy of the calculation. This is a bit easier to use than the spacing command.

Examples

deposit time=5 rate = 0.1 oxide grid=10

This command will deposit a 0.5mm layer of oxide on the top surface with ten layers of grid. This will result in a spacing of roughly 0.05mm in the direction normal to the surface.

deposit time=2 rate = 0.1 poly grid=5

This command deposits 0.2mm of polysilicon with a normal grid spacing of 0.04mm.

Bugs and Missing Features

There is no calculation performed of deposition parameters such as poly grain size or oxide density. It is rather stupid when it comes to material data.

Arbitrary materials can be created and deposited, but will not inherit reasonable defaults for oxide / silicide growth or dopant diffusion. These codes may core dump without appropriate defaults being defined. We need to implement some sort of inheritance for material parameters!

See Also

etch