No it's not, but it doesn't have to have your genetic material to be your child. If that's a route you do not want to take, that's your personal choice. It's just an option that IS available to you, should you decide to explore it.
BUT IT NOT THE SAME AS HAVING YOUR OWN WHEN YOU GO DO ADOPTION
The purpose of a ligation is so you do not have children again - If you want to have children you will have to see if you qualify for a reversal (depending on the type done, as well as damage it might not be successful), go through rounds of IVF, have a surrogate carry a child or adopt.