The documentation states precisely what kind of file it is: A sequence of binary instructions, nothing else. This is in contrast to an object file, for example, which contains not just a sequence of binary instructions, but auxilliary information such as stating addresses of functions or global data, where such information may be used in linking of objects files into executable, for example. Like many other platforms, CUDA uses ELF format (https://en.wikipedia.org/wiki/Executable_and_Linkable_Format) for object files.
I am not aware of any part of the CUDA toolchain that produces a raw binary of this nature. The typical situation where a raw binary would occur is if you simply copy instruction memory contents and save it to a binary file. I highly doubt there is a need for this in the regular course of programming with CUDA. I have been using CUDA for as long as it has existed (about 13 years) and have not needed this functionality yet.
What prompted you to ask the question? I sense there could be an XY problem here.