This problem usually occurs when the layer names in the rcx techfile run script RCXspiceINIT goes out of sync with the layers used in the lvs extract.rul file. During compilation of the techfile to generate the runscripts, commands such as "-res_blocking" requires layer names that are used in the extract.rul file. Sometimes the extract.rul file might be updated with some changes in layer names (e.g. rblock_poly1 might have now become rb_poly1). When this happens, you get the above errors.
Here is what you can do to resolve the problem:
a. Examine the Assura extract.rul file and make an intelligent guess on the new name for layer "rblock_poly1"
b. Copy the entire rcx technology directory to your home directory. The is the directory with the files caps2d, capsw3d, etc.
c. Copy the design.xcn file in the Assura lvs run dir to the rcx tech dir and rename it as "lvsfile"
d. Redo capgen compilation using the following cmd and the new layer names:
unix>capgen -C -length_units meters -cap_unit 1.0 -selected_paths_proper -p
poly1,capgen_gate,diffusion -no_cap_correction -cap_ground_layer
net_psub -dsub net_nwell,net_psub -lexclude poly2,poly1 -blocking
rblock_poly1,net_poly1 -res_blocking NEW_NAME,net_poly2
-res_blocking rblock_met1,net_met1 -res_blocking rblock_met2,net_met2
-res_blocking rblock_met3,net_met3 -res_blocking rblock_met4,net_met4
-sw3d -p2lvs p2lvsfile -lvs lvsfile .
Please also note the following:
a. With the introduction of the EXT package (latest version EXT815), it is no longer advisable to use the very out-dated Assura rcx to do parasitic extraction. Extraction should now be done using the unified extractor "qrc".
b. The corresponding replacement for "capgen" is "Techgen" from EXT package
c. The above error should be reported to the foundry so that they can updated their qrc/rcx packages.
d. I am not sure of the Assura version which you are using but it is advisable to use the latest Assura41HF4.