xSection: lift-off process

tnoradam

Negative values for the lateral component in etch() don't work. It produces non-sensical shapes, missing material. I wanted to visualize a lift-off resist process but got stuck there. I was able to piece it together by etching the layer.inverted with a positive angle, and the fill it with material. It does have a negative sidewall angle in the end, but maybe this could be updated ?

Besides that, there is no option in deposit() or grow() that would emulate a line-of-sight evaporation. Growing on a material with an overhang always deposits on its backside. I can set the lateral component to zero, but the overhang has a normal component to it that I cannot seem to get to forbid to grow on. Am I missing something here ? Maybe I am doing it all wrong and there is some other way niftier way ...

If not, can I request this to be considered for implementation into the next version ? It could literally be called evap(), the only difference to grow() and deposit() is that it would deposit/grow on surfaces that are at the interface to air (as normal), but not where there is material above it (with an airgap). Maybe "angle" could be an input variable ?

Thank you !!

Thomas.

Matthias

Hi Thomas,

the cross section script is very limited unfortunately. It is based on very simply geometrical operations and "line of sight" is definitely beyond the capabilities of this scheme.

I feel the current version is already exploring the very limits of this approach. I think that for advanced features new core algorithms will be required.

I'd also like to point out that xsection is a community project. Everyone's invited to contribute: https://github.com/klayoutmatthias/xsection

Just drop me a pull request.

Matthias