Hello, I am trying to find some specs concerning physical parameters such as silicon thickness and resistivities. I know about the pdk manual at readthedocs but I can't find some last few parameters. Does anyone know where I can find those?

Maybe resistivity is here https://skywater-pdk.readthedocs.io/en/main/rules/rcx.html#resistance-values When you say silicon thickness, are you referring to wafer thickness or the thickness of the layers above silicon (i.e., poly, metal, etc.)?

I want to find the thickness or "height" of the substrate, for example 150 um. I found the thickness of the above layers from the stack diagram, but it doesn't go below silicon surface.

There is no “the height” 🙂 The wafer during manufacturing is 0.75-1mm thick, and later it is back-lapped to the target thickness according to the package and is different depending on the package.