You can make the directory read-only in some way: with unix permissions (
chmod a-w), or with more stringent measures such as mounting a read-only filesystem at that spot. I don't think Linux offers a built-in way of preventing a single file from being created, without making the directory read-only as a whole. There is of course the multipurpose tool FUSE but I don't know of an existing FUSE filesystem that lets you create a file blacklist in this way.
You can try creating a dangling symbolic link, especially one pointing to a nonexistent file in a read-only directory. Depending on how the one program checks for the file existence and the other program tries to create the file, this may or may not work.
I'd recommend figuring out what program is creating that file and shutting it off. See Determine which process is creating a file