Generally, if you want to target your homepage for the single main keyword, you'd rather point keywords at the homepage.
Or have a single page, focused on the main keyword, and point all the links you can get to the page.
The thing is that your homepage is one of the most powerful pages on the site and it's a shame not to use it for your main keyword. On the other hand, if you want a great landing page (if your homepage isn't, but it should), you can shoot for a separate page. Won't make much sense, though.
What you can do when it comes to deep linking is to create pages with more focused keyword phrases that have the same main keyword in them. This will make your site more prominent in the field. Again, that's
the Long Tail of search, though, not targetting main keywords.